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sqlalchemy/lib/sqlalchemy/sql/compiler.py
T
Mike Bayer 2ce8a04e72 Invoke column_expression() for subsequent SELECTs in CompoundSelect 
Fixed bug where :meth:`.TypeEngine.column_expression` method would not be
applied to subsequent SELECT statements inside of a UNION or other
:class:`.CompoundSelect`, even though the SELECT statements are rendered at
the topmost level of the statement.   New logic now differentiates between
rendering the column expression, which is needed for all SELECTs in the
list, vs. gathering the returned data type for the result row, which is
needed only for the first SELECT.

Fixes: #4787
Change-Id: Iceb63e430e76d2365649aa25ead09c4e2a062e10
2019-07-29 14:52:40 -04:00

3805 lines
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# sql/compiler.py
# Copyright (C) 2005-2019 the SQLAlchemy authors and contributors
# <see AUTHORS file>
#
# This module is part of SQLAlchemy and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php
"""Base SQL and DDL compiler implementations.
Classes provided include:
:class:`.compiler.SQLCompiler` - renders SQL
strings
:class:`.compiler.DDLCompiler` - renders DDL
(data definition language) strings
:class:`.compiler.GenericTypeCompiler` - renders
type specification strings.
To generate user-defined SQL strings, see
:doc:`/ext/compiler`.
"""
import contextlib
import itertools
import re
from . import coercions
from . import crud
from . import elements
from . import functions
from . import operators
from . import roles
from . import schema
from . import selectable
from . import sqltypes
from .. import exc
from .. import util
RESERVED_WORDS = set(
[
"all",
"analyse",
"analyze",
"and",
"any",
"array",
"as",
"asc",
"asymmetric",
"authorization",
"between",
"binary",
"both",
"case",
"cast",
"check",
"collate",
"column",
"constraint",
"create",
"cross",
"current_date",
"current_role",
"current_time",
"current_timestamp",
"current_user",
"default",
"deferrable",
"desc",
"distinct",
"do",
"else",
"end",
"except",
"false",
"for",
"foreign",
"freeze",
"from",
"full",
"grant",
"group",
"having",
"ilike",
"in",
"initially",
"inner",
"intersect",
"into",
"is",
"isnull",
"join",
"leading",
"left",
"like",
"limit",
"localtime",
"localtimestamp",
"natural",
"new",
"not",
"notnull",
"null",
"off",
"offset",
"old",
"on",
"only",
"or",
"order",
"outer",
"overlaps",
"placing",
"primary",
"references",
"right",
"select",
"session_user",
"set",
"similar",
"some",
"symmetric",
"table",
"then",
"to",
"trailing",
"true",
"union",
"unique",
"user",
"using",
"verbose",
"when",
"where",
]
)
LEGAL_CHARACTERS = re.compile(r"^[A-Z0-9_$]+$", re.I)
LEGAL_CHARACTERS_PLUS_SPACE = re.compile(r"^[A-Z0-9_ $]+$", re.I)
ILLEGAL_INITIAL_CHARACTERS = {str(x) for x in range(0, 10)}.union(["$"])
FK_ON_DELETE = re.compile(
r"^(?:RESTRICT|CASCADE|SET NULL|NO ACTION|SET DEFAULT)$", re.I
)
FK_ON_UPDATE = re.compile(
r"^(?:RESTRICT|CASCADE|SET NULL|NO ACTION|SET DEFAULT)$", re.I
)
FK_INITIALLY = re.compile(r"^(?:DEFERRED|IMMEDIATE)$", re.I)
BIND_PARAMS = re.compile(r"(?<![:\w\$\x5c]):([\w\$]+)(?![:\w\$])", re.UNICODE)
BIND_PARAMS_ESC = re.compile(r"\x5c(:[\w\$]*)(?![:\w\$])", re.UNICODE)
BIND_TEMPLATES = {
"pyformat": "%%(%(name)s)s",
"qmark": "?",
"format": "%%s",
"numeric": ":[_POSITION]",
"named": ":%(name)s",
}
OPERATORS = {
# binary
operators.and_: " AND ",
operators.or_: " OR ",
operators.add: " + ",
operators.mul: " * ",
operators.sub: " - ",
operators.div: " / ",
operators.mod: " % ",
operators.truediv: " / ",
operators.neg: "-",
operators.lt: " < ",
operators.le: " <= ",
operators.ne: " != ",
operators.gt: " > ",
operators.ge: " >= ",
operators.eq: " = ",
operators.is_distinct_from: " IS DISTINCT FROM ",
operators.isnot_distinct_from: " IS NOT DISTINCT FROM ",
operators.concat_op: " || ",
operators.match_op: " MATCH ",
operators.notmatch_op: " NOT MATCH ",
operators.in_op: " IN ",
operators.notin_op: " NOT IN ",
operators.comma_op: ", ",
operators.from_: " FROM ",
operators.as_: " AS ",
operators.is_: " IS ",
operators.isnot: " IS NOT ",
operators.collate: " COLLATE ",
# unary
operators.exists: "EXISTS ",
operators.distinct_op: "DISTINCT ",
operators.inv: "NOT ",
operators.any_op: "ANY ",
operators.all_op: "ALL ",
# modifiers
operators.desc_op: " DESC",
operators.asc_op: " ASC",
operators.nullsfirst_op: " NULLS FIRST",
operators.nullslast_op: " NULLS LAST",
}
FUNCTIONS = {
functions.coalesce: "coalesce",
functions.current_date: "CURRENT_DATE",
functions.current_time: "CURRENT_TIME",
functions.current_timestamp: "CURRENT_TIMESTAMP",
functions.current_user: "CURRENT_USER",
functions.localtime: "LOCALTIME",
functions.localtimestamp: "LOCALTIMESTAMP",
functions.random: "random",
functions.sysdate: "sysdate",
functions.session_user: "SESSION_USER",
functions.user: "USER",
functions.cube: "CUBE",
functions.rollup: "ROLLUP",
functions.grouping_sets: "GROUPING SETS",
}
EXTRACT_MAP = {
"month": "month",
"day": "day",
"year": "year",
"second": "second",
"hour": "hour",
"doy": "doy",
"minute": "minute",
"quarter": "quarter",
"dow": "dow",
"week": "week",
"epoch": "epoch",
"milliseconds": "milliseconds",
"microseconds": "microseconds",
"timezone_hour": "timezone_hour",
"timezone_minute": "timezone_minute",
}
COMPOUND_KEYWORDS = {
selectable.CompoundSelect.UNION: "UNION",
selectable.CompoundSelect.UNION_ALL: "UNION ALL",
selectable.CompoundSelect.EXCEPT: "EXCEPT",
selectable.CompoundSelect.EXCEPT_ALL: "EXCEPT ALL",
selectable.CompoundSelect.INTERSECT: "INTERSECT",
selectable.CompoundSelect.INTERSECT_ALL: "INTERSECT ALL",
}
class Compiled(object):
"""Represent a compiled SQL or DDL expression.
The ``__str__`` method of the ``Compiled`` object should produce
the actual text of the statement. ``Compiled`` objects are
specific to their underlying database dialect, and also may
or may not be specific to the columns referenced within a
particular set of bind parameters. In no case should the
``Compiled`` object be dependent on the actual values of those
bind parameters, even though it may reference those values as
defaults.
"""
_cached_metadata = None
execution_options = util.immutabledict()
"""
Execution options propagated from the statement. In some cases,
sub-elements of the statement can modify these.
"""
def __init__(
self,
dialect,
statement,
bind=None,
schema_translate_map=None,
compile_kwargs=util.immutabledict(),
):
"""Construct a new :class:`.Compiled` object.
:param dialect: :class:`.Dialect` to compile against.
:param statement: :class:`.ClauseElement` to be compiled.
:param bind: Optional Engine or Connection to compile this
statement against.
:param schema_translate_map: dictionary of schema names to be
translated when forming the resultant SQL
.. versionadded:: 1.1
.. seealso::
:ref:`schema_translating`
:param compile_kwargs: additional kwargs that will be
passed to the initial call to :meth:`.Compiled.process`.
"""
self.dialect = dialect
self.bind = bind
self.preparer = self.dialect.identifier_preparer
if schema_translate_map:
self.preparer = self.preparer._with_schema_translate(
schema_translate_map
)
if statement is not None:
self.statement = statement
self.can_execute = statement.supports_execution
if self.can_execute:
self.execution_options = statement._execution_options
self.string = self.process(self.statement, **compile_kwargs)
@util.deprecated(
"0.7",
"The :meth:`.Compiled.compile` method is deprecated and will be "
"removed in a future release. The :class:`.Compiled` object "
"now runs its compilation within the constructor, and this method "
"does nothing.",
)
def compile(self):
"""Produce the internal string representation of this element.
"""
pass
def _execute_on_connection(self, connection, multiparams, params):
if self.can_execute:
return connection._execute_compiled(self, multiparams, params)
else:
raise exc.ObjectNotExecutableError(self.statement)
@property
def sql_compiler(self):
"""Return a Compiled that is capable of processing SQL expressions.
If this compiler is one, it would likely just return 'self'.
"""
raise NotImplementedError()
def process(self, obj, **kwargs):
return obj._compiler_dispatch(self, **kwargs)
def __str__(self):
"""Return the string text of the generated SQL or DDL."""
return self.string or ""
def construct_params(self, params=None):
"""Return the bind params for this compiled object.
:param params: a dict of string/object pairs whose values will
override bind values compiled in to the
statement.
"""
raise NotImplementedError()
@property
def params(self):
"""Return the bind params for this compiled object."""
return self.construct_params()
def execute(self, *multiparams, **params):
"""Execute this compiled object."""
e = self.bind
if e is None:
raise exc.UnboundExecutionError(
"This Compiled object is not bound to any Engine "
"or Connection.",
code="2afi",
)
return e._execute_compiled(self, multiparams, params)
def scalar(self, *multiparams, **params):
"""Execute this compiled object and return the result's
scalar value."""
return self.execute(*multiparams, **params).scalar()
class TypeCompiler(util.with_metaclass(util.EnsureKWArgType, object)):
"""Produces DDL specification for TypeEngine objects."""
ensure_kwarg = r"visit_\w+"
def __init__(self, dialect):
self.dialect = dialect
def process(self, type_, **kw):
return type_._compiler_dispatch(self, **kw)
# this was a Visitable, but to allow accurate detection of
# column elements this is actually a column element
class _CompileLabel(elements.ColumnElement):
"""lightweight label object which acts as an expression.Label."""
__visit_name__ = "label"
__slots__ = "element", "name"
def __init__(self, col, name, alt_names=()):
self.element = col
self.name = name
self._alt_names = (col,) + alt_names
@property
def proxy_set(self):
return self.element.proxy_set
@property
def type(self):
return self.element.type
def self_group(self, **kw):
return self
class SQLCompiler(Compiled):
"""Default implementation of :class:`.Compiled`.
Compiles :class:`.ClauseElement` objects into SQL strings.
"""
extract_map = EXTRACT_MAP
compound_keywords = COMPOUND_KEYWORDS
isdelete = isinsert = isupdate = False
"""class-level defaults which can be set at the instance
level to define if this Compiled instance represents
INSERT/UPDATE/DELETE
"""
isplaintext = False
returning = None
"""holds the "returning" collection of columns if
the statement is CRUD and defines returning columns
either implicitly or explicitly
"""
returning_precedes_values = False
"""set to True classwide to generate RETURNING
clauses before the VALUES or WHERE clause (i.e. MSSQL)
"""
render_table_with_column_in_update_from = False
"""set to True classwide to indicate the SET clause
in a multi-table UPDATE statement should qualify
columns with the table name (i.e. MySQL only)
"""
contains_expanding_parameters = False
"""True if we've encountered bindparam(..., expanding=True).
These need to be converted before execution time against the
string statement.
"""
ansi_bind_rules = False
"""SQL 92 doesn't allow bind parameters to be used
in the columns clause of a SELECT, nor does it allow
ambiguous expressions like "? = ?". A compiler
subclass can set this flag to False if the target
driver/DB enforces this
"""
_textual_ordered_columns = False
"""tell the result object that the column names as rendered are important,
but they are also "ordered" vs. what is in the compiled object here.
"""
_ordered_columns = True
"""
if False, means we can't be sure the list of entries
in _result_columns is actually the rendered order. Usually
True unless using an unordered TextualSelect.
"""
_numeric_binds = False
"""
True if paramstyle is "numeric". This paramstyle is trickier than
all the others.
"""
insert_prefetch = update_prefetch = ()
def __init__(
self, dialect, statement, column_keys=None, inline=False, **kwargs
):
"""Construct a new :class:`.SQLCompiler` object.
:param dialect: :class:`.Dialect` to be used
:param statement: :class:`.ClauseElement` to be compiled
:param column_keys: a list of column names to be compiled into an
INSERT or UPDATE statement.
:param inline: whether to generate INSERT statements as "inline", e.g.
not formatted to return any generated defaults
:param kwargs: additional keyword arguments to be consumed by the
superclass.
"""
self.column_keys = column_keys
# compile INSERT/UPDATE defaults/sequences inlined (no pre-
# execute)
self.inline = inline or getattr(statement, "inline", False)
# a dictionary of bind parameter keys to BindParameter
# instances.
self.binds = {}
# a dictionary of BindParameter instances to "compiled" names
# that are actually present in the generated SQL
self.bind_names = util.column_dict()
# stack which keeps track of nested SELECT statements
self.stack = []
# relates label names in the final SQL to a tuple of local
# column/label name, ColumnElement object (if any) and
# TypeEngine. ResultProxy uses this for type processing and
# column targeting
self._result_columns = []
# true if the paramstyle is positional
self.positional = dialect.positional
if self.positional:
self.positiontup = []
self._numeric_binds = dialect.paramstyle == "numeric"
self.bindtemplate = BIND_TEMPLATES[dialect.paramstyle]
self.ctes = None
self.label_length = (
dialect.label_length or dialect.max_identifier_length
)
# a map which tracks "anonymous" identifiers that are created on
# the fly here
self.anon_map = util.PopulateDict(self._process_anon)
# a map which tracks "truncated" names based on
# dialect.label_length or dialect.max_identifier_length
self.truncated_names = {}
Compiled.__init__(self, dialect, statement, **kwargs)
if (
self.isinsert or self.isupdate or self.isdelete
) and statement._returning:
self.returning = statement._returning
if self.positional and self._numeric_binds:
self._apply_numbered_params()
@property
def prefetch(self):
return list(self.insert_prefetch + self.update_prefetch)
@util.memoized_instancemethod
def _init_cte_state(self):
"""Initialize collections related to CTEs only if
a CTE is located, to save on the overhead of
these collections otherwise.
"""
# collect CTEs to tack on top of a SELECT
self.ctes = util.OrderedDict()
self.ctes_by_name = {}
self.ctes_recursive = False
if self.positional:
self.cte_positional = {}
@contextlib.contextmanager
def _nested_result(self):
"""special API to support the use case of 'nested result sets'"""
result_columns, ordered_columns = (
self._result_columns,
self._ordered_columns,
)
self._result_columns, self._ordered_columns = [], False
try:
if self.stack:
entry = self.stack[-1]
entry["need_result_map_for_nested"] = True
else:
entry = None
yield self._result_columns, self._ordered_columns
finally:
if entry:
entry.pop("need_result_map_for_nested")
self._result_columns, self._ordered_columns = (
result_columns,
ordered_columns,
)
def _apply_numbered_params(self):
poscount = itertools.count(1)
self.string = re.sub(
r"\[_POSITION\]", lambda m: str(util.next(poscount)), self.string
)
@util.memoized_property
def _bind_processors(self):
return dict(
(key, value)
for key, value in (
(
self.bind_names[bindparam],
bindparam.type._cached_bind_processor(self.dialect),
)
for bindparam in self.bind_names
)
if value is not None
)
def is_subquery(self):
return len(self.stack) > 1
@property
def sql_compiler(self):
return self
def construct_params(self, params=None, _group_number=None, _check=True):
"""return a dictionary of bind parameter keys and values"""
if params:
pd = {}
for bindparam in self.bind_names:
name = self.bind_names[bindparam]
if bindparam.key in params:
pd[name] = params[bindparam.key]
elif name in params:
pd[name] = params[name]
elif _check and bindparam.required:
if _group_number:
raise exc.InvalidRequestError(
"A value is required for bind parameter %r, "
"in parameter group %d"
% (bindparam.key, _group_number),
code="cd3x",
)
else:
raise exc.InvalidRequestError(
"A value is required for bind parameter %r"
% bindparam.key,
code="cd3x",
)
elif bindparam.callable:
pd[name] = bindparam.effective_value
else:
pd[name] = bindparam.value
return pd
else:
pd = {}
for bindparam in self.bind_names:
if _check and bindparam.required:
if _group_number:
raise exc.InvalidRequestError(
"A value is required for bind parameter %r, "
"in parameter group %d"
% (bindparam.key, _group_number),
code="cd3x",
)
else:
raise exc.InvalidRequestError(
"A value is required for bind parameter %r"
% bindparam.key,
code="cd3x",
)
if bindparam.callable:
pd[self.bind_names[bindparam]] = bindparam.effective_value
else:
pd[self.bind_names[bindparam]] = bindparam.value
return pd
@property
def params(self):
"""Return the bind param dictionary embedded into this
compiled object, for those values that are present."""
return self.construct_params(_check=False)
@util.dependencies("sqlalchemy.engine.result")
def _create_result_map(self, result):
"""utility method used for unit tests only."""
return result.ResultMetaData._create_result_map(self._result_columns)
def default_from(self):
"""Called when a SELECT statement has no froms, and no FROM clause is
to be appended.
Gives Oracle a chance to tack on a ``FROM DUAL`` to the string output.
"""
return ""
def visit_grouping(self, grouping, asfrom=False, **kwargs):
return "(" + grouping.element._compiler_dispatch(self, **kwargs) + ")"
def visit_label_reference(
self, element, within_columns_clause=False, **kwargs
):
if self.stack and self.dialect.supports_simple_order_by_label:
selectable = self.stack[-1]["selectable"]
with_cols, only_froms, only_cols = selectable._label_resolve_dict
if within_columns_clause:
resolve_dict = only_froms
else:
resolve_dict = only_cols
# this can be None in the case that a _label_reference()
# were subject to a replacement operation, in which case
# the replacement of the Label element may have changed
# to something else like a ColumnClause expression.
order_by_elem = element.element._order_by_label_element
if (
order_by_elem is not None
and order_by_elem.name in resolve_dict
and order_by_elem.shares_lineage(
resolve_dict[order_by_elem.name]
)
):
kwargs[
"render_label_as_label"
] = element.element._order_by_label_element
return self.process(
element.element,
within_columns_clause=within_columns_clause,
**kwargs
)
def visit_textual_label_reference(
self, element, within_columns_clause=False, **kwargs
):
if not self.stack:
# compiling the element outside of the context of a SELECT
return self.process(element._text_clause)
selectable = self.stack[-1]["selectable"]
with_cols, only_froms, only_cols = selectable._label_resolve_dict
try:
if within_columns_clause:
col = only_froms[element.element]
else:
col = with_cols[element.element]
except KeyError:
coercions._no_text_coercion(
element.element,
extra="Can't resolve label reference for ORDER BY / GROUP BY.",
exc_cls=exc.CompileError,
)
else:
kwargs["render_label_as_label"] = col
return self.process(
col, within_columns_clause=within_columns_clause, **kwargs
)
def visit_label(
self,
label,
add_to_result_map=None,
within_label_clause=False,
within_columns_clause=False,
render_label_as_label=None,
**kw
):
# only render labels within the columns clause
# or ORDER BY clause of a select. dialect-specific compilers
# can modify this behavior.
render_label_with_as = (
within_columns_clause and not within_label_clause
)
render_label_only = render_label_as_label is label
if render_label_only or render_label_with_as:
if isinstance(label.name, elements._truncated_label):
labelname = self._truncated_identifier("colident", label.name)
else:
labelname = label.name
if render_label_with_as:
if add_to_result_map is not None:
add_to_result_map(
labelname,
label.name,
(label, labelname) + label._alt_names,
label.type,
)
return (
label.element._compiler_dispatch(
self,
within_columns_clause=True,
within_label_clause=True,
**kw
)
+ OPERATORS[operators.as_]
+ self.preparer.format_label(label, labelname)
)
elif render_label_only:
return self.preparer.format_label(label, labelname)
else:
return label.element._compiler_dispatch(
self, within_columns_clause=False, **kw
)
def _fallback_column_name(self, column):
raise exc.CompileError(
"Cannot compile Column object until " "its 'name' is assigned."
)
def visit_column(
self, column, add_to_result_map=None, include_table=True, **kwargs
):
name = orig_name = column.name
if name is None:
name = self._fallback_column_name(column)
is_literal = column.is_literal
if not is_literal and isinstance(name, elements._truncated_label):
name = self._truncated_identifier("colident", name)
if add_to_result_map is not None:
add_to_result_map(
name, orig_name, (column, name, column.key), column.type
)
if is_literal:
# note we are not currently accommodating for
# literal_column(quoted_name('ident', True)) here
name = self.escape_literal_column(name)
else:
name = self.preparer.quote(name)
table = column.table
if table is None or not include_table or not table.named_with_column:
return name
else:
effective_schema = self.preparer.schema_for_object(table)
if effective_schema:
schema_prefix = (
self.preparer.quote_schema(effective_schema) + "."
)
else:
schema_prefix = ""
tablename = table.name
if isinstance(tablename, elements._truncated_label):
tablename = self._truncated_identifier("alias", tablename)
return schema_prefix + self.preparer.quote(tablename) + "." + name
def visit_collation(self, element, **kw):
return self.preparer.format_collation(element.collation)
def visit_fromclause(self, fromclause, **kwargs):
return fromclause.name
def visit_index(self, index, **kwargs):
return index.name
def visit_typeclause(self, typeclause, **kw):
kw["type_expression"] = typeclause
return self.dialect.type_compiler.process(typeclause.type, **kw)
def post_process_text(self, text):
if self.preparer._double_percents:
text = text.replace("%", "%%")
return text
def escape_literal_column(self, text):
if self.preparer._double_percents:
text = text.replace("%", "%%")
return text
def visit_textclause(self, textclause, **kw):
def do_bindparam(m):
name = m.group(1)
if name in textclause._bindparams:
return self.process(textclause._bindparams[name], **kw)
else:
return self.bindparam_string(name, **kw)
if not self.stack:
self.isplaintext = True
# un-escape any \:params
return BIND_PARAMS_ESC.sub(
lambda m: m.group(1),
BIND_PARAMS.sub(
do_bindparam, self.post_process_text(textclause.text)
),
)
def visit_textual_select(
self, taf, compound_index=None, asfrom=False, **kw
):
toplevel = not self.stack
entry = self._default_stack_entry if toplevel else self.stack[-1]
populate_result_map = (
toplevel
or (
compound_index == 0
and entry.get("need_result_map_for_compound", False)
)
or entry.get("need_result_map_for_nested", False)
)
if populate_result_map:
self._ordered_columns = (
self._textual_ordered_columns
) = taf.positional
for c in taf.column_args:
self.process(
c,
within_columns_clause=True,
add_to_result_map=self._add_to_result_map,
)
return self.process(taf.element, **kw)
def visit_null(self, expr, **kw):
return "NULL"
def visit_true(self, expr, **kw):
if self.dialect.supports_native_boolean:
return "true"
else:
return "1"
def visit_false(self, expr, **kw):
if self.dialect.supports_native_boolean:
return "false"
else:
return "0"
def visit_clauselist(self, clauselist, **kw):
sep = clauselist.operator
if sep is None:
sep = " "
else:
sep = OPERATORS[clauselist.operator]
text = sep.join(
s
for s in (
c._compiler_dispatch(self, **kw) for c in clauselist.clauses
)
if s
)
if clauselist._tuple_values and self.dialect.tuple_in_values:
text = "VALUES " + text
return text
def visit_case(self, clause, **kwargs):
x = "CASE "
if clause.value is not None:
x += clause.value._compiler_dispatch(self, **kwargs) + " "
for cond, result in clause.whens:
x += (
"WHEN "
+ cond._compiler_dispatch(self, **kwargs)
+ " THEN "
+ result._compiler_dispatch(self, **kwargs)
+ " "
)
if clause.else_ is not None:
x += (
"ELSE " + clause.else_._compiler_dispatch(self, **kwargs) + " "
)
x += "END"
return x
def visit_type_coerce(self, type_coerce, **kw):
return type_coerce.typed_expression._compiler_dispatch(self, **kw)
def visit_cast(self, cast, **kwargs):
return "CAST(%s AS %s)" % (
cast.clause._compiler_dispatch(self, **kwargs),
cast.typeclause._compiler_dispatch(self, **kwargs),
)
def _format_frame_clause(self, range_, **kw):
return "%s AND %s" % (
"UNBOUNDED PRECEDING"
if range_[0] is elements.RANGE_UNBOUNDED
else "CURRENT ROW"
if range_[0] is elements.RANGE_CURRENT
else "%s PRECEDING"
% (self.process(elements.literal(abs(range_[0])), **kw),)
if range_[0] < 0
else "%s FOLLOWING"
% (self.process(elements.literal(range_[0]), **kw),),
"UNBOUNDED FOLLOWING"
if range_[1] is elements.RANGE_UNBOUNDED
else "CURRENT ROW"
if range_[1] is elements.RANGE_CURRENT
else "%s PRECEDING"
% (self.process(elements.literal(abs(range_[1])), **kw),)
if range_[1] < 0
else "%s FOLLOWING"
% (self.process(elements.literal(range_[1]), **kw),),
)
def visit_over(self, over, **kwargs):
if over.range_:
range_ = "RANGE BETWEEN %s" % self._format_frame_clause(
over.range_, **kwargs
)
elif over.rows:
range_ = "ROWS BETWEEN %s" % self._format_frame_clause(
over.rows, **kwargs
)
else:
range_ = None
return "%s OVER (%s)" % (
over.element._compiler_dispatch(self, **kwargs),
" ".join(
[
"%s BY %s"
% (word, clause._compiler_dispatch(self, **kwargs))
for word, clause in (
("PARTITION", over.partition_by),
("ORDER", over.order_by),
)
if clause is not None and len(clause)
]
+ ([range_] if range_ else [])
),
)
def visit_withingroup(self, withingroup, **kwargs):
return "%s WITHIN GROUP (ORDER BY %s)" % (
withingroup.element._compiler_dispatch(self, **kwargs),
withingroup.order_by._compiler_dispatch(self, **kwargs),
)
def visit_funcfilter(self, funcfilter, **kwargs):
return "%s FILTER (WHERE %s)" % (
funcfilter.func._compiler_dispatch(self, **kwargs),
funcfilter.criterion._compiler_dispatch(self, **kwargs),
)
def visit_extract(self, extract, **kwargs):
field = self.extract_map.get(extract.field, extract.field)
return "EXTRACT(%s FROM %s)" % (
field,
extract.expr._compiler_dispatch(self, **kwargs),
)
def visit_function(self, func, add_to_result_map=None, **kwargs):
if add_to_result_map is not None:
add_to_result_map(func.name, func.name, (), func.type)
disp = getattr(self, "visit_%s_func" % func.name.lower(), None)
if disp:
return disp(func, **kwargs)
else:
name = FUNCTIONS.get(func.__class__, None)
if name:
if func._has_args:
name += "%(expr)s"
else:
name = func.name
name = (
self.preparer.quote(name)
if self.preparer._requires_quotes_illegal_chars(name)
else name
)
name = name + "%(expr)s"
return ".".join(
[
(
self.preparer.quote(tok)
if self.preparer._requires_quotes_illegal_chars(tok)
else tok
)
for tok in func.packagenames
]
+ [name]
) % {"expr": self.function_argspec(func, **kwargs)}
def visit_next_value_func(self, next_value, **kw):
return self.visit_sequence(next_value.sequence)
def visit_sequence(self, sequence, **kw):
raise NotImplementedError(
"Dialect '%s' does not support sequence increments."
% self.dialect.name
)
def function_argspec(self, func, **kwargs):
return func.clause_expr._compiler_dispatch(self, **kwargs)
def visit_compound_select(
self, cs, asfrom=False, compound_index=0, **kwargs
):
toplevel = not self.stack
entry = self._default_stack_entry if toplevel else self.stack[-1]
need_result_map = toplevel or (
compound_index == 0
and entry.get("need_result_map_for_compound", False)
)
self.stack.append(
{
"correlate_froms": entry["correlate_froms"],
"asfrom_froms": entry["asfrom_froms"],
"selectable": cs,
"need_result_map_for_compound": need_result_map,
}
)
keyword = self.compound_keywords.get(cs.keyword)
text = (" " + keyword + " ").join(
(
c._compiler_dispatch(
self, asfrom=asfrom, compound_index=i, **kwargs
)
for i, c in enumerate(cs.selects)
)
)
kwargs["include_table"] = False
text += self.group_by_clause(cs, **dict(asfrom=asfrom, **kwargs))
text += self.order_by_clause(cs, **kwargs)
text += (
(cs._limit_clause is not None or cs._offset_clause is not None)
and self.limit_clause(cs, **kwargs)
or ""
)
if self.ctes and toplevel:
text = self._render_cte_clause() + text
self.stack.pop(-1)
return text
def _get_operator_dispatch(self, operator_, qualifier1, qualifier2):
attrname = "visit_%s_%s%s" % (
operator_.__name__,
qualifier1,
"_" + qualifier2 if qualifier2 else "",
)
return getattr(self, attrname, None)
def visit_unary(self, unary, **kw):
if unary.operator:
if unary.modifier:
raise exc.CompileError(
"Unary expression does not support operator "
"and modifier simultaneously"
)
disp = self._get_operator_dispatch(
unary.operator, "unary", "operator"
)
if disp:
return disp(unary, unary.operator, **kw)
else:
return self._generate_generic_unary_operator(
unary, OPERATORS[unary.operator], **kw
)
elif unary.modifier:
disp = self._get_operator_dispatch(
unary.modifier, "unary", "modifier"
)
if disp:
return disp(unary, unary.modifier, **kw)
else:
return self._generate_generic_unary_modifier(
unary, OPERATORS[unary.modifier], **kw
)
else:
raise exc.CompileError(
"Unary expression has no operator or modifier"
)
def visit_istrue_unary_operator(self, element, operator, **kw):
if (
element._is_implicitly_boolean
or self.dialect.supports_native_boolean
):
return self.process(element.element, **kw)
else:
return "%s = 1" % self.process(element.element, **kw)
def visit_isfalse_unary_operator(self, element, operator, **kw):
if (
element._is_implicitly_boolean
or self.dialect.supports_native_boolean
):
return "NOT %s" % self.process(element.element, **kw)
else:
return "%s = 0" % self.process(element.element, **kw)
def visit_notmatch_op_binary(self, binary, operator, **kw):
return "NOT %s" % self.visit_binary(
binary, override_operator=operators.match_op
)
def _emit_empty_in_warning(self):
util.warn(
"The IN-predicate was invoked with an "
"empty sequence. This results in a "
"contradiction, which nonetheless can be "
"expensive to evaluate. Consider alternative "
"strategies for improved performance."
)
def visit_empty_in_op_binary(self, binary, operator, **kw):
if self.dialect._use_static_in:
return "1 != 1"
else:
if self.dialect._warn_on_empty_in:
self._emit_empty_in_warning()
return self.process(binary.left != binary.left)
def visit_empty_notin_op_binary(self, binary, operator, **kw):
if self.dialect._use_static_in:
return "1 = 1"
else:
if self.dialect._warn_on_empty_in:
self._emit_empty_in_warning()
return self.process(binary.left == binary.left)
def visit_empty_set_expr(self, element_types):
raise NotImplementedError(
"Dialect '%s' does not support empty set expression."
% self.dialect.name
)
def visit_binary(
self, binary, override_operator=None, eager_grouping=False, **kw
):
# don't allow "? = ?" to render
if (
self.ansi_bind_rules
and isinstance(binary.left, elements.BindParameter)
and isinstance(binary.right, elements.BindParameter)
):
kw["literal_binds"] = True
operator_ = override_operator or binary.operator
disp = self._get_operator_dispatch(operator_, "binary", None)
if disp:
return disp(binary, operator_, **kw)
else:
try:
opstring = OPERATORS[operator_]
except KeyError:
raise exc.UnsupportedCompilationError(self, operator_)
else:
return self._generate_generic_binary(binary, opstring, **kw)
def visit_function_as_comparison_op_binary(self, element, operator, **kw):
return self.process(element.sql_function, **kw)
def visit_mod_binary(self, binary, operator, **kw):
if self.preparer._double_percents:
return (
self.process(binary.left, **kw)
+ " %% "
+ self.process(binary.right, **kw)
)
else:
return (
self.process(binary.left, **kw)
+ " % "
+ self.process(binary.right, **kw)
)
def visit_custom_op_binary(self, element, operator, **kw):
kw["eager_grouping"] = operator.eager_grouping
return self._generate_generic_binary(
element, " " + operator.opstring + " ", **kw
)
def visit_custom_op_unary_operator(self, element, operator, **kw):
return self._generate_generic_unary_operator(
element, operator.opstring + " ", **kw
)
def visit_custom_op_unary_modifier(self, element, operator, **kw):
return self._generate_generic_unary_modifier(
element, " " + operator.opstring, **kw
)
def _generate_generic_binary(
self, binary, opstring, eager_grouping=False, **kw
):
_in_binary = kw.get("_in_binary", False)
kw["_in_binary"] = True
text = (
binary.left._compiler_dispatch(
self, eager_grouping=eager_grouping, **kw
)
+ opstring
+ binary.right._compiler_dispatch(
self, eager_grouping=eager_grouping, **kw
)
)
if _in_binary and eager_grouping:
text = "(%s)" % text
return text
def _generate_generic_unary_operator(self, unary, opstring, **kw):
return opstring + unary.element._compiler_dispatch(self, **kw)
def _generate_generic_unary_modifier(self, unary, opstring, **kw):
return unary.element._compiler_dispatch(self, **kw) + opstring
@util.memoized_property
def _like_percent_literal(self):
return elements.literal_column("'%'", type_=sqltypes.STRINGTYPE)
def visit_contains_op_binary(self, binary, operator, **kw):
binary = binary._clone()
percent = self._like_percent_literal
binary.right = percent.__add__(binary.right).__add__(percent)
return self.visit_like_op_binary(binary, operator, **kw)
def visit_notcontains_op_binary(self, binary, operator, **kw):
binary = binary._clone()
percent = self._like_percent_literal
binary.right = percent.__add__(binary.right).__add__(percent)
return self.visit_notlike_op_binary(binary, operator, **kw)
def visit_startswith_op_binary(self, binary, operator, **kw):
binary = binary._clone()
percent = self._like_percent_literal
binary.right = percent.__radd__(binary.right)
return self.visit_like_op_binary(binary, operator, **kw)
def visit_notstartswith_op_binary(self, binary, operator, **kw):
binary = binary._clone()
percent = self._like_percent_literal
binary.right = percent.__radd__(binary.right)
return self.visit_notlike_op_binary(binary, operator, **kw)
def visit_endswith_op_binary(self, binary, operator, **kw):
binary = binary._clone()
percent = self._like_percent_literal
binary.right = percent.__add__(binary.right)
return self.visit_like_op_binary(binary, operator, **kw)
def visit_notendswith_op_binary(self, binary, operator, **kw):
binary = binary._clone()
percent = self._like_percent_literal
binary.right = percent.__add__(binary.right)
return self.visit_notlike_op_binary(binary, operator, **kw)
def visit_like_op_binary(self, binary, operator, **kw):
escape = binary.modifiers.get("escape", None)
# TODO: use ternary here, not "and"/ "or"
return "%s LIKE %s" % (
binary.left._compiler_dispatch(self, **kw),
binary.right._compiler_dispatch(self, **kw),
) + (
" ESCAPE " + self.render_literal_value(escape, sqltypes.STRINGTYPE)
if escape
else ""
)
def visit_notlike_op_binary(self, binary, operator, **kw):
escape = binary.modifiers.get("escape", None)
return "%s NOT LIKE %s" % (
binary.left._compiler_dispatch(self, **kw),
binary.right._compiler_dispatch(self, **kw),
) + (
" ESCAPE " + self.render_literal_value(escape, sqltypes.STRINGTYPE)
if escape
else ""
)
def visit_ilike_op_binary(self, binary, operator, **kw):
escape = binary.modifiers.get("escape", None)
return "lower(%s) LIKE lower(%s)" % (
binary.left._compiler_dispatch(self, **kw),
binary.right._compiler_dispatch(self, **kw),
) + (
" ESCAPE " + self.render_literal_value(escape, sqltypes.STRINGTYPE)
if escape
else ""
)
def visit_notilike_op_binary(self, binary, operator, **kw):
escape = binary.modifiers.get("escape", None)
return "lower(%s) NOT LIKE lower(%s)" % (
binary.left._compiler_dispatch(self, **kw),
binary.right._compiler_dispatch(self, **kw),
) + (
" ESCAPE " + self.render_literal_value(escape, sqltypes.STRINGTYPE)
if escape
else ""
)
def visit_between_op_binary(self, binary, operator, **kw):
symmetric = binary.modifiers.get("symmetric", False)
return self._generate_generic_binary(
binary, " BETWEEN SYMMETRIC " if symmetric else " BETWEEN ", **kw
)
def visit_notbetween_op_binary(self, binary, operator, **kw):
symmetric = binary.modifiers.get("symmetric", False)
return self._generate_generic_binary(
binary,
" NOT BETWEEN SYMMETRIC " if symmetric else " NOT BETWEEN ",
**kw
)
def visit_bindparam(
self,
bindparam,
within_columns_clause=False,
literal_binds=False,
skip_bind_expression=False,
**kwargs
):
if not skip_bind_expression:
impl = bindparam.type.dialect_impl(self.dialect)
if impl._has_bind_expression:
bind_expression = impl.bind_expression(bindparam)
return self.process(
bind_expression,
skip_bind_expression=True,
within_columns_clause=within_columns_clause,
literal_binds=literal_binds,
**kwargs
)
if literal_binds or (within_columns_clause and self.ansi_bind_rules):
if bindparam.value is None and bindparam.callable is None:
raise exc.CompileError(
"Bind parameter '%s' without a "
"renderable value not allowed here." % bindparam.key
)
return self.render_literal_bindparam(
bindparam, within_columns_clause=True, **kwargs
)
name = self._truncate_bindparam(bindparam)
if name in self.binds:
existing = self.binds[name]
if existing is not bindparam:
if (
existing.unique or bindparam.unique
) and not existing.proxy_set.intersection(bindparam.proxy_set):
raise exc.CompileError(
"Bind parameter '%s' conflicts with "
"unique bind parameter of the same name"
% bindparam.key
)
elif existing._is_crud or bindparam._is_crud:
raise exc.CompileError(
"bindparam() name '%s' is reserved "
"for automatic usage in the VALUES or SET "
"clause of this "
"insert/update statement. Please use a "
"name other than column name when using bindparam() "
"with insert() or update() (for example, 'b_%s')."
% (bindparam.key, bindparam.key)
)
self.binds[bindparam.key] = self.binds[name] = bindparam
return self.bindparam_string(
name, expanding=bindparam.expanding, **kwargs
)
def render_literal_bindparam(self, bindparam, **kw):
value = bindparam.effective_value
return self.render_literal_value(value, bindparam.type)
def render_literal_value(self, value, type_):
"""Render the value of a bind parameter as a quoted literal.
This is used for statement sections that do not accept bind parameters
on the target driver/database.
This should be implemented by subclasses using the quoting services
of the DBAPI.
"""
processor = type_._cached_literal_processor(self.dialect)
if processor:
return processor(value)
else:
raise NotImplementedError(
"Don't know how to literal-quote value %r" % value
)
def _truncate_bindparam(self, bindparam):
if bindparam in self.bind_names:
return self.bind_names[bindparam]
bind_name = bindparam.key
if isinstance(bind_name, elements._truncated_label):
bind_name = self._truncated_identifier("bindparam", bind_name)
# add to bind_names for translation
self.bind_names[bindparam] = bind_name
return bind_name
def _truncated_identifier(self, ident_class, name):
if (ident_class, name) in self.truncated_names:
return self.truncated_names[(ident_class, name)]
anonname = name.apply_map(self.anon_map)
if len(anonname) > self.label_length - 6:
counter = self.truncated_names.get(ident_class, 1)
truncname = (
anonname[0 : max(self.label_length - 6, 0)]
+ "_"
+ hex(counter)[2:]
)
self.truncated_names[ident_class] = counter + 1
else:
truncname = anonname
self.truncated_names[(ident_class, name)] = truncname
return truncname
def _anonymize(self, name):
return name % self.anon_map
def _process_anon(self, key):
(ident, derived) = key.split(" ", 1)
anonymous_counter = self.anon_map.get(derived, 1)
self.anon_map[derived] = anonymous_counter + 1
return derived + "_" + str(anonymous_counter)
def bindparam_string(
self, name, positional_names=None, expanding=False, **kw
):
if self.positional:
if positional_names is not None:
positional_names.append(name)
else:
self.positiontup.append(name)
if expanding:
self.contains_expanding_parameters = True
return "([EXPANDING_%s])" % name
else:
return self.bindtemplate % {"name": name}
def visit_cte(
self,
cte,
asfrom=False,
ashint=False,
fromhints=None,
visiting_cte=None,
**kwargs
):
self._init_cte_state()
kwargs["visiting_cte"] = cte
if isinstance(cte.name, elements._truncated_label):
cte_name = self._truncated_identifier("alias", cte.name)
else:
cte_name = cte.name
is_new_cte = True
embedded_in_current_named_cte = False
if cte_name in self.ctes_by_name:
existing_cte = self.ctes_by_name[cte_name]
embedded_in_current_named_cte = visiting_cte is existing_cte
# we've generated a same-named CTE that we are enclosed in,
# or this is the same CTE. just return the name.
if cte in existing_cte._restates or cte is existing_cte:
is_new_cte = False
elif existing_cte in cte._restates:
# we've generated a same-named CTE that is
# enclosed in us - we take precedence, so
# discard the text for the "inner".
del self.ctes[existing_cte]
else:
raise exc.CompileError(
"Multiple, unrelated CTEs found with "
"the same name: %r" % cte_name
)
if asfrom or is_new_cte:
if cte._cte_alias is not None:
pre_alias_cte = cte._cte_alias
cte_pre_alias_name = cte._cte_alias.name
if isinstance(cte_pre_alias_name, elements._truncated_label):
cte_pre_alias_name = self._truncated_identifier(
"alias", cte_pre_alias_name
)
else:
pre_alias_cte = cte
cte_pre_alias_name = None
if is_new_cte:
self.ctes_by_name[cte_name] = cte
if (
"autocommit" in cte.element._execution_options
and "autocommit" not in self.execution_options
):
self.execution_options = self.execution_options.union(
{
"autocommit": cte.element._execution_options[
"autocommit"
]
}
)
if pre_alias_cte not in self.ctes:
self.visit_cte(pre_alias_cte, **kwargs)
if not cte_pre_alias_name and cte not in self.ctes:
if cte.recursive:
self.ctes_recursive = True
text = self.preparer.format_alias(cte, cte_name)
if cte.recursive:
if isinstance(cte.element, selectable.Select):
col_source = cte.element
elif isinstance(cte.element, selectable.CompoundSelect):
col_source = cte.element.selects[0]
else:
assert False
recur_cols = [
c
for c in util.unique_list(col_source.inner_columns)
if c is not None
]
text += "(%s)" % (
", ".join(
self.preparer.format_column(ident)
for ident in recur_cols
)
)
if self.positional:
kwargs["positional_names"] = self.cte_positional[cte] = []
assert kwargs.get("subquery", False) is False
text += " AS \n(%s)" % (
cte.element._compiler_dispatch(
self, asfrom=True, **kwargs
),
)
if cte._suffixes:
text += " " + self._generate_prefixes(
cte, cte._suffixes, **kwargs
)
self.ctes[cte] = text
if asfrom:
if not is_new_cte and embedded_in_current_named_cte:
return self.preparer.format_alias(cte, cte_name)
if cte_pre_alias_name:
text = self.preparer.format_alias(cte, cte_pre_alias_name)
if self.preparer._requires_quotes(cte_name):
cte_name = self.preparer.quote(cte_name)
text += self.get_render_as_alias_suffix(cte_name)
return text
else:
return self.preparer.format_alias(cte, cte_name)
def visit_alias(
self,
alias,
asfrom=False,
ashint=False,
iscrud=False,
fromhints=None,
subquery=False,
lateral=False,
enclosing_alias=None,
**kwargs
):
if enclosing_alias is not None and enclosing_alias.element is alias:
inner = alias.element._compiler_dispatch(
self,
asfrom=asfrom,
ashint=ashint,
iscrud=iscrud,
fromhints=fromhints,
lateral=lateral,
enclosing_alias=alias,
**kwargs
)
if subquery and (asfrom or lateral):
inner = "(%s)" % (inner,)
return inner
else:
enclosing_alias = kwargs["enclosing_alias"] = alias
if asfrom or ashint:
if isinstance(alias.name, elements._truncated_label):
alias_name = self._truncated_identifier("alias", alias.name)
else:
alias_name = alias.name
if ashint:
return self.preparer.format_alias(alias, alias_name)
elif asfrom:
inner = alias.element._compiler_dispatch(
self, asfrom=True, lateral=lateral, **kwargs
)
if subquery:
inner = "(%s)" % (inner,)
ret = inner + self.get_render_as_alias_suffix(
self.preparer.format_alias(alias, alias_name)
)
if fromhints and alias in fromhints:
ret = self.format_from_hint_text(
ret, alias, fromhints[alias], iscrud
)
return ret
else:
# note we cancel the "subquery" flag here as well
return alias.element._compiler_dispatch(
self, lateral=lateral, **kwargs
)
def visit_subquery(self, subquery, **kw):
kw["subquery"] = True
return self.visit_alias(subquery, **kw)
def visit_lateral(self, lateral, **kw):
kw["lateral"] = True
return "LATERAL %s" % self.visit_alias(lateral, **kw)
def visit_tablesample(self, tablesample, asfrom=False, **kw):
text = "%s TABLESAMPLE %s" % (
self.visit_alias(tablesample, asfrom=True, **kw),
tablesample._get_method()._compiler_dispatch(self, **kw),
)
if tablesample.seed is not None:
text += " REPEATABLE (%s)" % (
tablesample.seed._compiler_dispatch(self, **kw)
)
return text
def get_render_as_alias_suffix(self, alias_name_text):
return " AS " + alias_name_text
def _add_to_result_map(self, keyname, name, objects, type_):
self._result_columns.append((keyname, name, objects, type_))
def _label_select_column(
self,
select,
column,
populate_result_map,
asfrom,
column_clause_args,
name=None,
within_columns_clause=True,
need_column_expressions=False,
):
"""produce labeled columns present in a select()."""
impl = column.type.dialect_impl(self.dialect)
if impl._has_column_expression and (
need_column_expressions or populate_result_map
):
col_expr = impl.column_expression(column)
if populate_result_map:
def add_to_result_map(keyname, name, objects, type_):
self._add_to_result_map(
keyname, name, (column,) + objects, type_
)
else:
add_to_result_map = None
else:
col_expr = column
if populate_result_map:
add_to_result_map = self._add_to_result_map
else:
add_to_result_map = None
if not within_columns_clause:
result_expr = col_expr
elif isinstance(column, elements.Label):
if col_expr is not column:
result_expr = _CompileLabel(
col_expr, column.name, alt_names=(column.element,)
)
else:
result_expr = col_expr
elif select is not None and name:
result_expr = _CompileLabel(
col_expr, name, alt_names=(column._key_label,)
)
elif (
asfrom
and isinstance(column, elements.ColumnClause)
and not column.is_literal
and column.table is not None
and not isinstance(column.table, selectable.Select)
):
result_expr = _CompileLabel(
col_expr,
coercions.expect(roles.TruncatedLabelRole, column.name),
alt_names=(column.key,),
)
elif (
not isinstance(column, elements.TextClause)
and (
not isinstance(column, elements.UnaryExpression)
or column.wraps_column_expression
)
and (
not hasattr(column, "name")
or isinstance(column, functions.Function)
)
):
result_expr = _CompileLabel(col_expr, column.anon_label)
elif col_expr is not column:
# TODO: are we sure "column" has a .name and .key here ?
# assert isinstance(column, elements.ColumnClause)
result_expr = _CompileLabel(
col_expr,
coercions.expect(roles.TruncatedLabelRole, column.name),
alt_names=(column.key,),
)
else:
result_expr = col_expr
column_clause_args.update(
within_columns_clause=within_columns_clause,
add_to_result_map=add_to_result_map,
)
return result_expr._compiler_dispatch(self, **column_clause_args)
def format_from_hint_text(self, sqltext, table, hint, iscrud):
hinttext = self.get_from_hint_text(table, hint)
if hinttext:
sqltext += " " + hinttext
return sqltext
def get_select_hint_text(self, byfroms):
return None
def get_from_hint_text(self, table, text):
return None
def get_crud_hint_text(self, table, text):
return None
def get_statement_hint_text(self, hint_texts):
return " ".join(hint_texts)
def _transform_select_for_nested_joins(self, select):
"""Rewrite any "a JOIN (b JOIN c)" expression as
"a JOIN (select * from b JOIN c) AS anon", to support
databases that can't parse a parenthesized join correctly
(i.e. sqlite < 3.7.16).
"""
cloned = {}
column_translate = [{}]
created = set()
def visit(element, **kw):
if element in column_translate[-1]:
return column_translate[-1][element]
elif element in cloned:
return cloned[element]
newelem = cloned[element] = element._clone()
if (
newelem._is_from_clause
and newelem._is_join
and isinstance(newelem.right, selectable.FromGrouping)
):
newelem._reset_exported()
newelem.left = visit(newelem.left, **kw)
right = visit(newelem.right, **kw)
selectable_ = selectable.Select(
[right.element], use_labels=True
).alias()
created.add(selectable_)
created.update(selectable_.c)
for c in selectable_.c:
c._key_label = c.key
c._label = c.name
translate_dict = dict(
zip(newelem.right.element.c, selectable_.c)
)
# translating from both the old and the new
# because different select() structures will lead us
# to traverse differently
translate_dict[right.element.left] = selectable_
translate_dict[right.element.right] = selectable_
translate_dict[newelem.right.element.left] = selectable_
translate_dict[newelem.right.element.right] = selectable_
# propagate translations that we've gained
# from nested visit(newelem.right) outwards
# to the enclosing select here. this happens
# only when we have more than one level of right
# join nesting, i.e. "a JOIN (b JOIN (c JOIN d))"
for k, v in list(column_translate[-1].items()):
if v in translate_dict:
# remarkably, no current ORM tests (May 2013)
# hit this condition, only test_join_rewriting
# does.
column_translate[-1][k] = translate_dict[v]
column_translate[-1].update(translate_dict)
newelem.right = selectable_
newelem.onclause = visit(newelem.onclause, **kw)
elif newelem._is_from_container:
# if we hit an Alias, CompoundSelect or ScalarSelect, put a
# marker in the stack.
kw["transform_clue"] = "select_container"
newelem._copy_internals(clone=visit, **kw)
elif newelem._is_returns_rows and newelem._is_select_statement:
barrier_select = (
kw.get("transform_clue", None) == "select_container"
)
# if we're still descended from an
# Alias/CompoundSelect/ScalarSelect, we're
# in a FROM clause, so start with a new translate collection
if barrier_select:
column_translate.append({})
kw["transform_clue"] = "inside_select"
if not newelem._is_select_container:
froms = newelem.froms
newelem._raw_columns = list(newelem.selected_columns)
newelem._from_obj.update(froms)
newelem._reset_memoizations()
newelem._copy_internals(clone=visit, **kw)
if barrier_select:
del column_translate[-1]
else:
newelem._copy_internals(clone=visit, **kw)
return newelem
return visit(select)
def _transform_result_map_for_nested_joins(
self, select, transformed_select
):
self._result_columns[:] = [
result_rec
if col is tcol
else (
result_rec[0],
name,
tuple([col if obj is tcol else obj for obj in result_rec[2]]),
result_rec[3],
)
for result_rec, (name, col), (tname, tcol) in zip(
self._result_columns,
select._columns_plus_names,
transformed_select._columns_plus_names,
)
]
# TODO: it's not anticipated that we need to correct anon_map
# however if we do, this is what it looks like:
# for (name, col), (tname, tcol) in zip(
# select._columns_plus_names,
# transformed_select._columns_plus_names,
# ):
# if isinstance(name, elements._anonymous_label) and name != tname:
# m1 = re.match(r"^%\((\d+ .+?)\)s$", name)
# m2 = re.match(r"^%\((\d+ .+?)\)s$", tname)
# self.anon_map[m1.group(1)] = self.anon_map[m2.group(1)]
_default_stack_entry = util.immutabledict(
[("correlate_froms", frozenset()), ("asfrom_froms", frozenset())]
)
def _display_froms_for_select(self, select, asfrom, lateral=False):
# utility method to help external dialects
# get the correct from list for a select.
# specifically the oracle dialect needs this feature
# right now.
toplevel = not self.stack
entry = self._default_stack_entry if toplevel else self.stack[-1]
correlate_froms = entry["correlate_froms"]
asfrom_froms = entry["asfrom_froms"]
if asfrom and not lateral:
froms = select._get_display_froms(
explicit_correlate_froms=correlate_froms.difference(
asfrom_froms
),
implicit_correlate_froms=(),
)
else:
froms = select._get_display_froms(
explicit_correlate_froms=correlate_froms,
implicit_correlate_froms=asfrom_froms,
)
return froms
def visit_select(
self,
select,
asfrom=False,
fromhints=None,
compound_index=0,
nested_join_translation=False,
select_wraps_for=None,
lateral=False,
**kwargs
):
needs_nested_translation = (
select.use_labels
and not nested_join_translation
and not self.stack
and not self.dialect.supports_right_nested_joins
)
if needs_nested_translation:
transformed_select = self._transform_select_for_nested_joins(
select
)
text = self.visit_select(
transformed_select,
asfrom=asfrom,
fromhints=fromhints,
compound_index=compound_index,
nested_join_translation=True,
**kwargs
)
toplevel = not self.stack
entry = self._default_stack_entry if toplevel else self.stack[-1]
populate_result_map = need_column_expressions = (
toplevel
or entry.get("need_result_map_for_compound", False)
or entry.get("need_result_map_for_nested", False)
)
if compound_index > 0:
populate_result_map = False
# this was first proposed as part of #3372; however, it is not
# reached in current tests and could possibly be an assertion
# instead.
if not populate_result_map and "add_to_result_map" in kwargs:
del kwargs["add_to_result_map"]
if needs_nested_translation:
if populate_result_map:
self._transform_result_map_for_nested_joins(
select, transformed_select
)
return text
froms = self._setup_select_stack(select, entry, asfrom, lateral)
column_clause_args = kwargs.copy()
column_clause_args.update(
{"within_label_clause": False, "within_columns_clause": False}
)
text = "SELECT " # we're off to a good start !
if select._hints:
hint_text, byfrom = self._setup_select_hints(select)
if hint_text:
text += hint_text + " "
else:
byfrom = None
if select._prefixes:
text += self._generate_prefixes(select, select._prefixes, **kwargs)
text += self.get_select_precolumns(select, **kwargs)
# the actual list of columns to print in the SELECT column list.
inner_columns = [
c
for c in [
self._label_select_column(
select,
column,
populate_result_map,
asfrom,
column_clause_args,
name=name,
need_column_expressions=need_column_expressions,
)
for name, column in select._columns_plus_names
]
if c is not None
]
if populate_result_map and select_wraps_for is not None:
# if this select is a compiler-generated wrapper,
# rewrite the targeted columns in the result map
translate = dict(
zip(
[name for (key, name) in select._columns_plus_names],
[
name
for (key, name) in select_wraps_for._columns_plus_names
],
)
)
self._result_columns = [
(key, name, tuple(translate.get(o, o) for o in obj), type_)
for key, name, obj, type_ in self._result_columns
]
text = self._compose_select_body(
text, select, inner_columns, froms, byfrom, kwargs
)
if select._statement_hints:
per_dialect = [
ht
for (dialect_name, ht) in select._statement_hints
if dialect_name in ("*", self.dialect.name)
]
if per_dialect:
text += " " + self.get_statement_hint_text(per_dialect)
if self.ctes and toplevel:
text = self._render_cte_clause() + text
if select._suffixes:
text += " " + self._generate_prefixes(
select, select._suffixes, **kwargs
)
self.stack.pop(-1)
return text
def _setup_select_hints(self, select):
byfrom = dict(
[
(
from_,
hinttext
% {"name": from_._compiler_dispatch(self, ashint=True)},
)
for (from_, dialect), hinttext in select._hints.items()
if dialect in ("*", self.dialect.name)
]
)
hint_text = self.get_select_hint_text(byfrom)
return hint_text, byfrom
def _setup_select_stack(self, select, entry, asfrom, lateral):
correlate_froms = entry["correlate_froms"]
asfrom_froms = entry["asfrom_froms"]
if asfrom and not lateral:
froms = select._get_display_froms(
explicit_correlate_froms=correlate_froms.difference(
asfrom_froms
),
implicit_correlate_froms=(),
)
else:
froms = select._get_display_froms(
explicit_correlate_froms=correlate_froms,
implicit_correlate_froms=asfrom_froms,
)
new_correlate_froms = set(selectable._from_objects(*froms))
all_correlate_froms = new_correlate_froms.union(correlate_froms)
new_entry = {
"asfrom_froms": new_correlate_froms,
"correlate_froms": all_correlate_froms,
"selectable": select,
}
self.stack.append(new_entry)
return froms
def _compose_select_body(
self, text, select, inner_columns, froms, byfrom, kwargs
):
text += ", ".join(inner_columns)
if froms:
text += " \nFROM "
if select._hints:
text += ", ".join(
[
f._compiler_dispatch(
self, asfrom=True, fromhints=byfrom, **kwargs
)
for f in froms
]
)
else:
text += ", ".join(
[
f._compiler_dispatch(self, asfrom=True, **kwargs)
for f in froms
]
)
else:
text += self.default_from()
if select._whereclause is not None:
t = select._whereclause._compiler_dispatch(self, **kwargs)
if t:
text += " \nWHERE " + t
if select._group_by_clause.clauses:
text += self.group_by_clause(select, **kwargs)
if select._having is not None:
t = select._having._compiler_dispatch(self, **kwargs)
if t:
text += " \nHAVING " + t
if select._order_by_clause.clauses:
text += self.order_by_clause(select, **kwargs)
if (
select._limit_clause is not None
or select._offset_clause is not None
):
text += self.limit_clause(select, **kwargs)
if select._for_update_arg is not None:
text += self.for_update_clause(select, **kwargs)
return text
def _generate_prefixes(self, stmt, prefixes, **kw):
clause = " ".join(
prefix._compiler_dispatch(self, **kw)
for prefix, dialect_name in prefixes
if dialect_name is None or dialect_name == self.dialect.name
)
if clause:
clause += " "
return clause
def _render_cte_clause(self):
if self.positional:
self.positiontup = (
sum([self.cte_positional[cte] for cte in self.ctes], [])
+ self.positiontup
)
cte_text = self.get_cte_preamble(self.ctes_recursive) + " "
cte_text += ", \n".join([txt for txt in self.ctes.values()])
cte_text += "\n "
return cte_text
def get_cte_preamble(self, recursive):
if recursive:
return "WITH RECURSIVE"
else:
return "WITH"
def get_select_precolumns(self, select, **kw):
"""Called when building a ``SELECT`` statement, position is just
before column list.
"""
return select._distinct and "DISTINCT " or ""
def group_by_clause(self, select, **kw):
"""allow dialects to customize how GROUP BY is rendered."""
group_by = select._group_by_clause._compiler_dispatch(self, **kw)
if group_by:
return " GROUP BY " + group_by
else:
return ""
def order_by_clause(self, select, **kw):
"""allow dialects to customize how ORDER BY is rendered."""
order_by = select._order_by_clause._compiler_dispatch(self, **kw)
if order_by:
return " ORDER BY " + order_by
else:
return ""
def for_update_clause(self, select, **kw):
return " FOR UPDATE"
def returning_clause(self, stmt, returning_cols):
raise exc.CompileError(
"RETURNING is not supported by this "
"dialect's statement compiler."
)
def limit_clause(self, select, **kw):
text = ""
if select._limit_clause is not None:
text += "\n LIMIT " + self.process(select._limit_clause, **kw)
if select._offset_clause is not None:
if select._limit_clause is None:
text += "\n LIMIT -1"
text += " OFFSET " + self.process(select._offset_clause, **kw)
return text
def visit_table(
self,
table,
asfrom=False,
iscrud=False,
ashint=False,
fromhints=None,
use_schema=True,
**kwargs
):
if asfrom or ashint:
effective_schema = self.preparer.schema_for_object(table)
if use_schema and effective_schema:
ret = (
self.preparer.quote_schema(effective_schema)
+ "."
+ self.preparer.quote(table.name)
)
else:
ret = self.preparer.quote(table.name)
if fromhints and table in fromhints:
ret = self.format_from_hint_text(
ret, table, fromhints[table], iscrud
)
return ret
else:
return ""
def visit_join(self, join, asfrom=False, **kwargs):
if join.full:
join_type = " FULL OUTER JOIN "
elif join.isouter:
join_type = " LEFT OUTER JOIN "
else:
join_type = " JOIN "
return (
join.left._compiler_dispatch(self, asfrom=True, **kwargs)
+ join_type
+ join.right._compiler_dispatch(self, asfrom=True, **kwargs)
+ " ON "
# TODO: likely need asfrom=True here?
+ join.onclause._compiler_dispatch(self, **kwargs)
)
def _setup_crud_hints(self, stmt, table_text):
dialect_hints = dict(
[
(table, hint_text)
for (table, dialect), hint_text in stmt._hints.items()
if dialect in ("*", self.dialect.name)
]
)
if stmt.table in dialect_hints:
table_text = self.format_from_hint_text(
table_text, stmt.table, dialect_hints[stmt.table], True
)
return dialect_hints, table_text
def visit_insert(self, insert_stmt, **kw):
toplevel = not self.stack
self.stack.append(
{
"correlate_froms": set(),
"asfrom_froms": set(),
"selectable": insert_stmt,
}
)
crud_params = crud._setup_crud_params(
self, insert_stmt, crud.ISINSERT, **kw
)
if (
not crud_params
and not self.dialect.supports_default_values
and not self.dialect.supports_empty_insert
):
raise exc.CompileError(
"The '%s' dialect with current database "
"version settings does not support empty "
"inserts." % self.dialect.name
)
if insert_stmt._has_multi_parameters:
if not self.dialect.supports_multivalues_insert:
raise exc.CompileError(
"The '%s' dialect with current database "
"version settings does not support "
"in-place multirow inserts." % self.dialect.name
)
crud_params_single = crud_params[0]
else:
crud_params_single = crud_params
preparer = self.preparer
supports_default_values = self.dialect.supports_default_values
text = "INSERT "
if insert_stmt._prefixes:
text += self._generate_prefixes(
insert_stmt, insert_stmt._prefixes, **kw
)
text += "INTO "
table_text = preparer.format_table(insert_stmt.table)
if insert_stmt._hints:
_, table_text = self._setup_crud_hints(insert_stmt, table_text)
text += table_text
if crud_params_single or not supports_default_values:
text += " (%s)" % ", ".join(
[preparer.format_column(c[0]) for c in crud_params_single]
)
if self.returning or insert_stmt._returning:
returning_clause = self.returning_clause(
insert_stmt, self.returning or insert_stmt._returning
)
if self.returning_precedes_values:
text += " " + returning_clause
else:
returning_clause = None
if insert_stmt.select is not None:
select_text = self.process(self._insert_from_select, **kw)
if self.ctes and toplevel and self.dialect.cte_follows_insert:
text += " %s%s" % (self._render_cte_clause(), select_text)
else:
text += " %s" % select_text
elif not crud_params and supports_default_values:
text += " DEFAULT VALUES"
elif insert_stmt._has_multi_parameters:
text += " VALUES %s" % (
", ".join(
"(%s)" % (", ".join(c[1] for c in crud_param_set))
for crud_param_set in crud_params
)
)
else:
text += " VALUES (%s)" % ", ".join([c[1] for c in crud_params])
if insert_stmt._post_values_clause is not None:
post_values_clause = self.process(
insert_stmt._post_values_clause, **kw
)
if post_values_clause:
text += " " + post_values_clause
if returning_clause and not self.returning_precedes_values:
text += " " + returning_clause
if self.ctes and toplevel and not self.dialect.cte_follows_insert:
text = self._render_cte_clause() + text
self.stack.pop(-1)
return text
def update_limit_clause(self, update_stmt):
"""Provide a hook for MySQL to add LIMIT to the UPDATE"""
return None
def update_tables_clause(self, update_stmt, from_table, extra_froms, **kw):
"""Provide a hook to override the initial table clause
in an UPDATE statement.
MySQL overrides this.
"""
kw["asfrom"] = True
return from_table._compiler_dispatch(self, iscrud=True, **kw)
def update_from_clause(
self, update_stmt, from_table, extra_froms, from_hints, **kw
):
"""Provide a hook to override the generation of an
UPDATE..FROM clause.
MySQL and MSSQL override this.
"""
raise NotImplementedError(
"This backend does not support multiple-table "
"criteria within UPDATE"
)
def visit_update(self, update_stmt, **kw):
toplevel = not self.stack
extra_froms = update_stmt._extra_froms
is_multitable = bool(extra_froms)
if is_multitable:
# main table might be a JOIN
main_froms = set(selectable._from_objects(update_stmt.table))
render_extra_froms = [
f for f in extra_froms if f not in main_froms
]
correlate_froms = main_froms.union(extra_froms)
else:
render_extra_froms = []
correlate_froms = {update_stmt.table}
self.stack.append(
{
"correlate_froms": correlate_froms,
"asfrom_froms": correlate_froms,
"selectable": update_stmt,
}
)
text = "UPDATE "
if update_stmt._prefixes:
text += self._generate_prefixes(
update_stmt, update_stmt._prefixes, **kw
)
table_text = self.update_tables_clause(
update_stmt, update_stmt.table, render_extra_froms, **kw
)
crud_params = crud._setup_crud_params(
self, update_stmt, crud.ISUPDATE, **kw
)
if update_stmt._hints:
dialect_hints, table_text = self._setup_crud_hints(
update_stmt, table_text
)
else:
dialect_hints = None
text += table_text
text += " SET "
include_table = (
is_multitable and self.render_table_with_column_in_update_from
)
text += ", ".join(
c[0]._compiler_dispatch(self, include_table=include_table)
+ "="
+ c[1]
for c in crud_params
)
if self.returning or update_stmt._returning:
if self.returning_precedes_values:
text += " " + self.returning_clause(
update_stmt, self.returning or update_stmt._returning
)
if extra_froms:
extra_from_text = self.update_from_clause(
update_stmt,
update_stmt.table,
render_extra_froms,
dialect_hints,
**kw
)
if extra_from_text:
text += " " + extra_from_text
if update_stmt._whereclause is not None:
t = self.process(update_stmt._whereclause, **kw)
if t:
text += " WHERE " + t
limit_clause = self.update_limit_clause(update_stmt)
if limit_clause:
text += " " + limit_clause
if (
self.returning or update_stmt._returning
) and not self.returning_precedes_values:
text += " " + self.returning_clause(
update_stmt, self.returning or update_stmt._returning
)
if self.ctes and toplevel:
text = self._render_cte_clause() + text
self.stack.pop(-1)
return text
@util.memoized_property
def _key_getters_for_crud_column(self):
return crud._key_getters_for_crud_column(self, self.statement)
def delete_extra_from_clause(
self, update_stmt, from_table, extra_froms, from_hints, **kw
):
"""Provide a hook to override the generation of an
DELETE..FROM clause.
This can be used to implement DELETE..USING for example.
MySQL and MSSQL override this.
"""
raise NotImplementedError(
"This backend does not support multiple-table "
"criteria within DELETE"
)
def delete_table_clause(self, delete_stmt, from_table, extra_froms):
return from_table._compiler_dispatch(self, asfrom=True, iscrud=True)
def visit_delete(self, delete_stmt, **kw):
toplevel = not self.stack
crud._setup_crud_params(self, delete_stmt, crud.ISDELETE, **kw)
extra_froms = delete_stmt._extra_froms
correlate_froms = {delete_stmt.table}.union(extra_froms)
self.stack.append(
{
"correlate_froms": correlate_froms,
"asfrom_froms": correlate_froms,
"selectable": delete_stmt,
}
)
text = "DELETE "
if delete_stmt._prefixes:
text += self._generate_prefixes(
delete_stmt, delete_stmt._prefixes, **kw
)
text += "FROM "
table_text = self.delete_table_clause(
delete_stmt, delete_stmt.table, extra_froms
)
if delete_stmt._hints:
dialect_hints, table_text = self._setup_crud_hints(
delete_stmt, table_text
)
else:
dialect_hints = None
text += table_text
if delete_stmt._returning:
if self.returning_precedes_values:
text += " " + self.returning_clause(
delete_stmt, delete_stmt._returning
)
if extra_froms:
extra_from_text = self.delete_extra_from_clause(
delete_stmt,
delete_stmt.table,
extra_froms,
dialect_hints,
**kw
)
if extra_from_text:
text += " " + extra_from_text
if delete_stmt._whereclause is not None:
t = delete_stmt._whereclause._compiler_dispatch(self, **kw)
if t:
text += " WHERE " + t
if delete_stmt._returning and not self.returning_precedes_values:
text += " " + self.returning_clause(
delete_stmt, delete_stmt._returning
)
if self.ctes and toplevel:
text = self._render_cte_clause() + text
self.stack.pop(-1)
return text
def visit_savepoint(self, savepoint_stmt):
return "SAVEPOINT %s" % self.preparer.format_savepoint(savepoint_stmt)
def visit_rollback_to_savepoint(self, savepoint_stmt):
return "ROLLBACK TO SAVEPOINT %s" % self.preparer.format_savepoint(
savepoint_stmt
)
def visit_release_savepoint(self, savepoint_stmt):
return "RELEASE SAVEPOINT %s" % self.preparer.format_savepoint(
savepoint_stmt
)
class StrSQLCompiler(SQLCompiler):
"""A :class:`.SQLCompiler` subclass which allows a small selection
of non-standard SQL features to render into a string value.
The :class:`.StrSQLCompiler` is invoked whenever a Core expression
element is directly stringified without calling upon the
:meth:`.ClauseElement.compile` method. It can render a limited set
of non-standard SQL constructs to assist in basic stringification,
however for more substantial custom or dialect-specific SQL constructs,
it will be necessary to make use of :meth:`.ClauseElement.compile`
directly.
.. seealso::
:ref:`faq_sql_expression_string`
"""
def _fallback_column_name(self, column):
return "<name unknown>"
def visit_getitem_binary(self, binary, operator, **kw):
return "%s[%s]" % (
self.process(binary.left, **kw),
self.process(binary.right, **kw),
)
def visit_json_getitem_op_binary(self, binary, operator, **kw):
return self.visit_getitem_binary(binary, operator, **kw)
def visit_json_path_getitem_op_binary(self, binary, operator, **kw):
return self.visit_getitem_binary(binary, operator, **kw)
def visit_sequence(self, seq, **kw):
return "<next sequence value: %s>" % self.preparer.format_sequence(seq)
def returning_clause(self, stmt, returning_cols):
columns = [
self._label_select_column(None, c, True, False, {})
for c in elements._select_iterables(returning_cols)
]
return "RETURNING " + ", ".join(columns)
def update_from_clause(
self, update_stmt, from_table, extra_froms, from_hints, **kw
):
return "FROM " + ", ".join(
t._compiler_dispatch(self, asfrom=True, fromhints=from_hints, **kw)
for t in extra_froms
)
def delete_extra_from_clause(
self, update_stmt, from_table, extra_froms, from_hints, **kw
):
return ", " + ", ".join(
t._compiler_dispatch(self, asfrom=True, fromhints=from_hints, **kw)
for t in extra_froms
)
class DDLCompiler(Compiled):
@util.memoized_property
def sql_compiler(self):
return self.dialect.statement_compiler(self.dialect, None)
@util.memoized_property
def type_compiler(self):
return self.dialect.type_compiler
def construct_params(self, params=None):
return None
def visit_ddl(self, ddl, **kwargs):
# table events can substitute table and schema name
context = ddl.context
if isinstance(ddl.target, schema.Table):
context = context.copy()
preparer = self.preparer
path = preparer.format_table_seq(ddl.target)
if len(path) == 1:
table, sch = path[0], ""
else:
table, sch = path[-1], path[0]
context.setdefault("table", table)
context.setdefault("schema", sch)
context.setdefault("fullname", preparer.format_table(ddl.target))
return self.sql_compiler.post_process_text(ddl.statement % context)
def visit_create_schema(self, create):
schema = self.preparer.format_schema(create.element)
return "CREATE SCHEMA " + schema
def visit_drop_schema(self, drop):
schema = self.preparer.format_schema(drop.element)
text = "DROP SCHEMA " + schema
if drop.cascade:
text += " CASCADE"
return text
def visit_create_table(self, create):
table = create.element
preparer = self.preparer
text = "\nCREATE "
if table._prefixes:
text += " ".join(table._prefixes) + " "
text += "TABLE " + preparer.format_table(table) + " "
create_table_suffix = self.create_table_suffix(table)
if create_table_suffix:
text += create_table_suffix + " "
text += "("
separator = "\n"
# if only one primary key, specify it along with the column
first_pk = False
for create_column in create.columns:
column = create_column.element
try:
processed = self.process(
create_column, first_pk=column.primary_key and not first_pk
)
if processed is not None:
text += separator
separator = ", \n"
text += "\t" + processed
if column.primary_key:
first_pk = True
except exc.CompileError as ce:
util.raise_from_cause(
exc.CompileError(
util.u("(in table '%s', column '%s'): %s")
% (table.description, column.name, ce.args[0])
)
)
const = self.create_table_constraints(
table,
_include_foreign_key_constraints=create.include_foreign_key_constraints, # noqa
)
if const:
text += separator + "\t" + const
text += "\n)%s\n\n" % self.post_create_table(table)
return text
def visit_create_column(self, create, first_pk=False):
column = create.element
if column.system:
return None
text = self.get_column_specification(column, first_pk=first_pk)
const = " ".join(
self.process(constraint) for constraint in column.constraints
)
if const:
text += " " + const
return text
def create_table_constraints(
self, table, _include_foreign_key_constraints=None
):
# On some DB order is significant: visit PK first, then the
# other constraints (engine.ReflectionTest.testbasic failed on FB2)
constraints = []
if table.primary_key:
constraints.append(table.primary_key)
all_fkcs = table.foreign_key_constraints
if _include_foreign_key_constraints is not None:
omit_fkcs = all_fkcs.difference(_include_foreign_key_constraints)
else:
omit_fkcs = set()
constraints.extend(
[
c
for c in table._sorted_constraints
if c is not table.primary_key and c not in omit_fkcs
]
)
return ", \n\t".join(
p
for p in (
self.process(constraint)
for constraint in constraints
if (
constraint._create_rule is None
or constraint._create_rule(self)
)
and (
not self.dialect.supports_alter
or not getattr(constraint, "use_alter", False)
)
)
if p is not None
)
def visit_drop_table(self, drop):
return "\nDROP TABLE " + self.preparer.format_table(drop.element)
def visit_drop_view(self, drop):
return "\nDROP VIEW " + self.preparer.format_table(drop.element)
def _verify_index_table(self, index):
if index.table is None:
raise exc.CompileError(
"Index '%s' is not associated " "with any table." % index.name
)
def visit_create_index(
self, create, include_schema=False, include_table_schema=True
):
index = create.element
self._verify_index_table(index)
preparer = self.preparer
text = "CREATE "
if index.unique:
text += "UNIQUE "
text += "INDEX %s ON %s (%s)" % (
self._prepared_index_name(index, include_schema=include_schema),
preparer.format_table(
index.table, use_schema=include_table_schema
),
", ".join(
self.sql_compiler.process(
expr, include_table=False, literal_binds=True
)
for expr in index.expressions
),
)
return text
def visit_drop_index(self, drop):
index = drop.element
return "\nDROP INDEX " + self._prepared_index_name(
index, include_schema=True
)
def _prepared_index_name(self, index, include_schema=False):
if index.table is not None:
effective_schema = self.preparer.schema_for_object(index.table)
else:
effective_schema = None
if include_schema and effective_schema:
schema_name = self.preparer.quote_schema(effective_schema)
else:
schema_name = None
index_name = self.preparer.format_index(index)
if schema_name:
index_name = schema_name + "." + index_name
return index_name
def visit_add_constraint(self, create):
return "ALTER TABLE %s ADD %s" % (
self.preparer.format_table(create.element.table),
self.process(create.element),
)
def visit_set_table_comment(self, create):
return "COMMENT ON TABLE %s IS %s" % (
self.preparer.format_table(create.element),
self.sql_compiler.render_literal_value(
create.element.comment, sqltypes.String()
),
)
def visit_drop_table_comment(self, drop):
return "COMMENT ON TABLE %s IS NULL" % self.preparer.format_table(
drop.element
)
def visit_set_column_comment(self, create):
return "COMMENT ON COLUMN %s IS %s" % (
self.preparer.format_column(
create.element, use_table=True, use_schema=True
),
self.sql_compiler.render_literal_value(
create.element.comment, sqltypes.String()
),
)
def visit_drop_column_comment(self, drop):
return "COMMENT ON COLUMN %s IS NULL" % self.preparer.format_column(
drop.element, use_table=True
)
def visit_create_sequence(self, create):
text = "CREATE SEQUENCE %s" % self.preparer.format_sequence(
create.element
)
if create.element.increment is not None:
text += " INCREMENT BY %d" % create.element.increment
if create.element.start is not None:
text += " START WITH %d" % create.element.start
if create.element.minvalue is not None:
text += " MINVALUE %d" % create.element.minvalue
if create.element.maxvalue is not None:
text += " MAXVALUE %d" % create.element.maxvalue
if create.element.nominvalue is not None:
text += " NO MINVALUE"
if create.element.nomaxvalue is not None:
text += " NO MAXVALUE"
if create.element.cache is not None:
text += " CACHE %d" % create.element.cache
if create.element.order is True:
text += " ORDER"
if create.element.cycle is not None:
text += " CYCLE"
return text
def visit_drop_sequence(self, drop):
return "DROP SEQUENCE %s" % self.preparer.format_sequence(drop.element)
def visit_drop_constraint(self, drop):
constraint = drop.element
if constraint.name is not None:
formatted_name = self.preparer.format_constraint(constraint)
else:
formatted_name = None
if formatted_name is None:
raise exc.CompileError(
"Can't emit DROP CONSTRAINT for constraint %r; "
"it has no name" % drop.element
)
return "ALTER TABLE %s DROP CONSTRAINT %s%s" % (
self.preparer.format_table(drop.element.table),
formatted_name,
drop.cascade and " CASCADE" or "",
)
def get_column_specification(self, column, **kwargs):
colspec = (
self.preparer.format_column(column)
+ " "
+ self.dialect.type_compiler.process(
column.type, type_expression=column
)
)
default = self.get_column_default_string(column)
if default is not None:
colspec += " DEFAULT " + default
if not column.nullable:
colspec += " NOT NULL"
return colspec
def create_table_suffix(self, table):
return ""
def post_create_table(self, table):
return ""
def get_column_default_string(self, column):
if isinstance(column.server_default, schema.DefaultClause):
if isinstance(column.server_default.arg, util.string_types):
return self.sql_compiler.render_literal_value(
column.server_default.arg, sqltypes.STRINGTYPE
)
else:
return self.sql_compiler.process(
column.server_default.arg, literal_binds=True
)
else:
return None
def visit_check_constraint(self, constraint):
text = ""
if constraint.name is not None:
formatted_name = self.preparer.format_constraint(constraint)
if formatted_name is not None:
text += "CONSTRAINT %s " % formatted_name
text += "CHECK (%s)" % self.sql_compiler.process(
constraint.sqltext, include_table=False, literal_binds=True
)
text += self.define_constraint_deferrability(constraint)
return text
def visit_column_check_constraint(self, constraint):
text = ""
if constraint.name is not None:
formatted_name = self.preparer.format_constraint(constraint)
if formatted_name is not None:
text += "CONSTRAINT %s " % formatted_name
text += "CHECK (%s)" % self.sql_compiler.process(
constraint.sqltext, include_table=False, literal_binds=True
)
text += self.define_constraint_deferrability(constraint)
return text
def visit_primary_key_constraint(self, constraint):
if len(constraint) == 0:
return ""
text = ""
if constraint.name is not None:
formatted_name = self.preparer.format_constraint(constraint)
if formatted_name is not None:
text += "CONSTRAINT %s " % formatted_name
text += "PRIMARY KEY "
text += "(%s)" % ", ".join(
self.preparer.quote(c.name)
for c in (
constraint.columns_autoinc_first
if constraint._implicit_generated
else constraint.columns
)
)
text += self.define_constraint_deferrability(constraint)
return text
def visit_foreign_key_constraint(self, constraint):
preparer = self.preparer
text = ""
if constraint.name is not None:
formatted_name = self.preparer.format_constraint(constraint)
if formatted_name is not None:
text += "CONSTRAINT %s " % formatted_name
remote_table = list(constraint.elements)[0].column.table
text += "FOREIGN KEY(%s) REFERENCES %s (%s)" % (
", ".join(
preparer.quote(f.parent.name) for f in constraint.elements
),
self.define_constraint_remote_table(
constraint, remote_table, preparer
),
", ".join(
preparer.quote(f.column.name) for f in constraint.elements
),
)
text += self.define_constraint_match(constraint)
text += self.define_constraint_cascades(constraint)
text += self.define_constraint_deferrability(constraint)
return text
def define_constraint_remote_table(self, constraint, table, preparer):
"""Format the remote table clause of a CREATE CONSTRAINT clause."""
return preparer.format_table(table)
def visit_unique_constraint(self, constraint):
if len(constraint) == 0:
return ""
text = ""
if constraint.name is not None:
formatted_name = self.preparer.format_constraint(constraint)
text += "CONSTRAINT %s " % formatted_name
text += "UNIQUE (%s)" % (
", ".join(self.preparer.quote(c.name) for c in constraint)
)
text += self.define_constraint_deferrability(constraint)
return text
def define_constraint_cascades(self, constraint):
text = ""
if constraint.ondelete is not None:
text += " ON DELETE %s" % self.preparer.validate_sql_phrase(
constraint.ondelete, FK_ON_DELETE
)
if constraint.onupdate is not None:
text += " ON UPDATE %s" % self.preparer.validate_sql_phrase(
constraint.onupdate, FK_ON_UPDATE
)
return text
def define_constraint_deferrability(self, constraint):
text = ""
if constraint.deferrable is not None:
if constraint.deferrable:
text += " DEFERRABLE"
else:
text += " NOT DEFERRABLE"
if constraint.initially is not None:
text += " INITIALLY %s" % self.preparer.validate_sql_phrase(
constraint.initially, FK_INITIALLY
)
return text
def define_constraint_match(self, constraint):
text = ""
if constraint.match is not None:
text += " MATCH %s" % constraint.match
return text
class GenericTypeCompiler(TypeCompiler):
def visit_FLOAT(self, type_, **kw):
return "FLOAT"
def visit_REAL(self, type_, **kw):
return "REAL"
def visit_NUMERIC(self, type_, **kw):
if type_.precision is None:
return "NUMERIC"
elif type_.scale is None:
return "NUMERIC(%(precision)s)" % {"precision": type_.precision}
else:
return "NUMERIC(%(precision)s, %(scale)s)" % {
"precision": type_.precision,
"scale": type_.scale,
}
def visit_DECIMAL(self, type_, **kw):
if type_.precision is None:
return "DECIMAL"
elif type_.scale is None:
return "DECIMAL(%(precision)s)" % {"precision": type_.precision}
else:
return "DECIMAL(%(precision)s, %(scale)s)" % {
"precision": type_.precision,
"scale": type_.scale,
}
def visit_INTEGER(self, type_, **kw):
return "INTEGER"
def visit_SMALLINT(self, type_, **kw):
return "SMALLINT"
def visit_BIGINT(self, type_, **kw):
return "BIGINT"
def visit_TIMESTAMP(self, type_, **kw):
return "TIMESTAMP"
def visit_DATETIME(self, type_, **kw):
return "DATETIME"
def visit_DATE(self, type_, **kw):
return "DATE"
def visit_TIME(self, type_, **kw):
return "TIME"
def visit_CLOB(self, type_, **kw):
return "CLOB"
def visit_NCLOB(self, type_, **kw):
return "NCLOB"
def _render_string_type(self, type_, name):
text = name
if type_.length:
text += "(%d)" % type_.length
if type_.collation:
text += ' COLLATE "%s"' % type_.collation
return text
def visit_CHAR(self, type_, **kw):
return self._render_string_type(type_, "CHAR")
def visit_NCHAR(self, type_, **kw):
return self._render_string_type(type_, "NCHAR")
def visit_VARCHAR(self, type_, **kw):
return self._render_string_type(type_, "VARCHAR")
def visit_NVARCHAR(self, type_, **kw):
return self._render_string_type(type_, "NVARCHAR")
def visit_TEXT(self, type_, **kw):
return self._render_string_type(type_, "TEXT")
def visit_BLOB(self, type_, **kw):
return "BLOB"
def visit_BINARY(self, type_, **kw):
return "BINARY" + (type_.length and "(%d)" % type_.length or "")
def visit_VARBINARY(self, type_, **kw):
return "VARBINARY" + (type_.length and "(%d)" % type_.length or "")
def visit_BOOLEAN(self, type_, **kw):
return "BOOLEAN"
def visit_large_binary(self, type_, **kw):
return self.visit_BLOB(type_, **kw)
def visit_boolean(self, type_, **kw):
return self.visit_BOOLEAN(type_, **kw)
def visit_time(self, type_, **kw):
return self.visit_TIME(type_, **kw)
def visit_datetime(self, type_, **kw):
return self.visit_DATETIME(type_, **kw)
def visit_date(self, type_, **kw):
return self.visit_DATE(type_, **kw)
def visit_big_integer(self, type_, **kw):
return self.visit_BIGINT(type_, **kw)
def visit_small_integer(self, type_, **kw):
return self.visit_SMALLINT(type_, **kw)
def visit_integer(self, type_, **kw):
return self.visit_INTEGER(type_, **kw)
def visit_real(self, type_, **kw):
return self.visit_REAL(type_, **kw)
def visit_float(self, type_, **kw):
return self.visit_FLOAT(type_, **kw)
def visit_numeric(self, type_, **kw):
return self.visit_NUMERIC(type_, **kw)
def visit_string(self, type_, **kw):
return self.visit_VARCHAR(type_, **kw)
def visit_unicode(self, type_, **kw):
return self.visit_VARCHAR(type_, **kw)
def visit_text(self, type_, **kw):
return self.visit_TEXT(type_, **kw)
def visit_unicode_text(self, type_, **kw):
return self.visit_TEXT(type_, **kw)
def visit_enum(self, type_, **kw):
return self.visit_VARCHAR(type_, **kw)
def visit_null(self, type_, **kw):
raise exc.CompileError(
"Can't generate DDL for %r; "
"did you forget to specify a "
"type on this Column?" % type_
)
def visit_type_decorator(self, type_, **kw):
return self.process(type_.type_engine(self.dialect), **kw)
def visit_user_defined(self, type_, **kw):
return type_.get_col_spec(**kw)
class StrSQLTypeCompiler(GenericTypeCompiler):
def __getattr__(self, key):
if key.startswith("visit_"):
return self._visit_unknown
else:
raise AttributeError(key)
def _visit_unknown(self, type_, **kw):
return "%s" % type_.__class__.__name__
class IdentifierPreparer(object):
"""Handle quoting and case-folding of identifiers based on options."""
reserved_words = RESERVED_WORDS
legal_characters = LEGAL_CHARACTERS
illegal_initial_characters = ILLEGAL_INITIAL_CHARACTERS
schema_for_object = schema._schema_getter(None)
def __init__(
self,
dialect,
initial_quote='"',
final_quote=None,
escape_quote='"',
quote_case_sensitive_collations=True,
omit_schema=False,
):
"""Construct a new ``IdentifierPreparer`` object.
initial_quote
Character that begins a delimited identifier.
final_quote
Character that ends a delimited identifier. Defaults to
`initial_quote`.
omit_schema
Prevent prepending schema name. Useful for databases that do
not support schemae.
"""
self.dialect = dialect
self.initial_quote = initial_quote
self.final_quote = final_quote or self.initial_quote
self.escape_quote = escape_quote
self.escape_to_quote = self.escape_quote * 2
self.omit_schema = omit_schema
self.quote_case_sensitive_collations = quote_case_sensitive_collations
self._strings = {}
self._double_percents = self.dialect.paramstyle in (
"format",
"pyformat",
)
def _with_schema_translate(self, schema_translate_map):
prep = self.__class__.__new__(self.__class__)
prep.__dict__.update(self.__dict__)
prep.schema_for_object = schema._schema_getter(schema_translate_map)
return prep
def _escape_identifier(self, value):
"""Escape an identifier.
Subclasses should override this to provide database-dependent
escaping behavior.
"""
value = value.replace(self.escape_quote, self.escape_to_quote)
if self._double_percents:
value = value.replace("%", "%%")
return value
def _unescape_identifier(self, value):
"""Canonicalize an escaped identifier.
Subclasses should override this to provide database-dependent
unescaping behavior that reverses _escape_identifier.
"""
return value.replace(self.escape_to_quote, self.escape_quote)
def validate_sql_phrase(self, element, reg):
"""keyword sequence filter.
a filter for elements that are intended to represent keyword sequences,
such as "INITIALLY", "INITIALLY DEFERRED", etc. no special characters
should be present.
.. versionadded:: 1.3
"""
if element is not None and not reg.match(element):
raise exc.CompileError(
"Unexpected SQL phrase: %r (matching against %r)"
% (element, reg.pattern)
)
return element
def quote_identifier(self, value):
"""Quote an identifier.
Subclasses should override this to provide database-dependent
quoting behavior.
"""
return (
self.initial_quote
+ self._escape_identifier(value)
+ self.final_quote
)
def _requires_quotes(self, value):
"""Return True if the given identifier requires quoting."""
lc_value = value.lower()
return (
lc_value in self.reserved_words
or value[0] in self.illegal_initial_characters
or not self.legal_characters.match(util.text_type(value))
or (lc_value != value)
)
def _requires_quotes_illegal_chars(self, value):
"""Return True if the given identifier requires quoting, but
not taking case convention into account."""
return not self.legal_characters.match(util.text_type(value))
def quote_schema(self, schema, force=None):
"""Conditionally quote a schema name.
The name is quoted if it is a reserved word, contains quote-necessary
characters, or is an instance of :class:`.quoted_name` which includes
``quote`` set to ``True``.
Subclasses can override this to provide database-dependent
quoting behavior for schema names.
:param schema: string schema name
:param force: unused
.. deprecated:: 0.9
The :paramref:`.IdentifierPreparer.quote_schema.force`
parameter is deprecated and will be removed in a future
release. This flag has no effect on the behavior of the
:meth:`.IdentifierPreparer.quote` method; please refer to
:class:`.quoted_name`.
"""
if force is not None:
# not using the util.deprecated_params() decorator in this
# case because of the additional function call overhead on this
# very performance-critical spot.
util.warn_deprecated(
"The IdentifierPreparer.quote_schema.force parameter is "
"deprecated and will be removed in a future release. This "
"flag has no effect on the behavior of the "
"IdentifierPreparer.quote method; please refer to "
"quoted_name()."
)
return self.quote(schema)
def quote(self, ident, force=None):
"""Conditionally quote an identfier.
The identifier is quoted if it is a reserved word, contains
quote-necessary characters, or is an instance of
:class:`.quoted_name` which includes ``quote`` set to ``True``.
Subclasses can override this to provide database-dependent
quoting behavior for identifier names.
:param ident: string identifier
:param force: unused
.. deprecated:: 0.9
The :paramref:`.IdentifierPreparer.quote.force`
parameter is deprecated and will be removed in a future
release. This flag has no effect on the behavior of the
:meth:`.IdentifierPreparer.quote` method; please refer to
:class:`.quoted_name`.
"""
if force is not None:
# not using the util.deprecated_params() decorator in this
# case because of the additional function call overhead on this
# very performance-critical spot.
util.warn_deprecated(
"The IdentifierPreparer.quote.force parameter is "
"deprecated and will be removed in a future release. This "
"flag has no effect on the behavior of the "
"IdentifierPreparer.quote method; please refer to "
"quoted_name()."
)
force = getattr(ident, "quote", None)
if force is None:
if ident in self._strings:
return self._strings[ident]
else:
if self._requires_quotes(ident):
self._strings[ident] = self.quote_identifier(ident)
else:
self._strings[ident] = ident
return self._strings[ident]
elif force:
return self.quote_identifier(ident)
else:
return ident
def format_collation(self, collation_name):
if self.quote_case_sensitive_collations:
return self.quote(collation_name)
else:
return collation_name
def format_sequence(self, sequence, use_schema=True):
name = self.quote(sequence.name)
effective_schema = self.schema_for_object(sequence)
if (
not self.omit_schema
and use_schema
and effective_schema is not None
):
name = self.quote_schema(effective_schema) + "." + name
return name
def format_label(self, label, name=None):
return self.quote(name or label.name)
def format_alias(self, alias, name=None):
return self.quote(name or alias.name)
def format_savepoint(self, savepoint, name=None):
# Running the savepoint name through quoting is unnecessary
# for all known dialects. This is here to support potential
# third party use cases
ident = name or savepoint.ident
if self._requires_quotes(ident):
ident = self.quote_identifier(ident)
return ident
@util.dependencies("sqlalchemy.sql.naming")
def format_constraint(self, naming, constraint):
if isinstance(constraint.name, elements._defer_name):
name = naming._constraint_name_for_table(
constraint, constraint.table
)
if name is None:
if isinstance(constraint.name, elements._defer_none_name):
return None
else:
name = constraint.name
else:
name = constraint.name
if isinstance(name, elements._truncated_label):
if constraint.__visit_name__ == "index":
max_ = (
self.dialect.max_index_name_length
or self.dialect.max_identifier_length
)
else:
max_ = self.dialect.max_identifier_length
if len(name) > max_:
name = name[0 : max_ - 8] + "_" + util.md5_hex(name)[-4:]
else:
self.dialect.validate_identifier(name)
return self.quote(name)
def format_index(self, index):
return self.format_constraint(index)
def format_table(self, table, use_schema=True, name=None):
"""Prepare a quoted table and schema name."""
if name is None:
name = table.name
result = self.quote(name)
effective_schema = self.schema_for_object(table)
if not self.omit_schema and use_schema and effective_schema:
result = self.quote_schema(effective_schema) + "." + result
return result
def format_schema(self, name):
"""Prepare a quoted schema name."""
return self.quote(name)
def format_column(
self,
column,
use_table=False,
name=None,
table_name=None,
use_schema=False,
):
"""Prepare a quoted column name."""
if name is None:
name = column.name
if not getattr(column, "is_literal", False):
if use_table:
return (
self.format_table(
column.table, use_schema=use_schema, name=table_name
)
+ "."
+ self.quote(name)
)
else:
return self.quote(name)
else:
# literal textual elements get stuck into ColumnClause a lot,
# which shouldn't get quoted
if use_table:
return (
self.format_table(
column.table, use_schema=use_schema, name=table_name
)
+ "."
+ name
)
else:
return name
def format_table_seq(self, table, use_schema=True):
"""Format table name and schema as a tuple."""
# Dialects with more levels in their fully qualified references
# ('database', 'owner', etc.) could override this and return
# a longer sequence.
effective_schema = self.schema_for_object(table)
if not self.omit_schema and use_schema and effective_schema:
return (
self.quote_schema(effective_schema),
self.format_table(table, use_schema=False),
)
else:
return (self.format_table(table, use_schema=False),)
@util.memoized_property
def _r_identifiers(self):
initial, final, escaped_final = [
re.escape(s)
for s in (
self.initial_quote,
self.final_quote,
self._escape_identifier(self.final_quote),
)
]
r = re.compile(
r"(?:"
r"(?:%(initial)s((?:%(escaped)s|[^%(final)s])+)%(final)s"
r"|([^\.]+))(?=\.|$))+"
% {"initial": initial, "final": final, "escaped": escaped_final}
)
return r
def unformat_identifiers(self, identifiers):
"""Unpack 'schema.table.column'-like strings into components."""
r = self._r_identifiers
return [
self._unescape_identifier(i)
for i in [a or b for a, b in r.findall(identifiers)]
]
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