Refined the behavior of :meth:`.Operators.op` such that in all cases,
if the :paramref:`.Operators.op.is_comparison` flag is set to True,
the return type of the resulting expression will be
:class:`.Boolean`, and if the flag is False, the return type of the
resulting expression will be the same type as that of the left-hand
expression, which is the typical default behavior of other operators.
Also added a new parameter :paramref:`.Operators.op.return_type` as well
as a helper method :meth:`.Operators.bool_op`.
Change-Id: Ifc8553cd4037d741b84b70a9702cbd530f1a9de0
Fixes: #4063
The operator precedence for all comparison operators such as LIKE, IS,
IN, MATCH, equals, greater than, less than, etc. has all been merged
into one level, so that expressions which make use of these against
each other will produce parentheses between them. This suits the
stated operator precedence of databases like Oracle, MySQL and others
which place all of these operators as equal precedence, as well as
Postgresql as of 9.5 which has also flattened its operator precendence.
Co-authored-by: Mike Bayer <mike_mp@zzzcomputing.com>
Fixes: #3999
Change-Id: I3f3d5124a64af0d376361cdf15a97e2e703be56f
Pull-request: https://github.com/zzzeek/sqlalchemy/pull/367
This patch moves the "doubling" of percent signs into
the base compiler and makes it completely a product
of whether or not the paramstyle is format/pyformat or
not. Without this paramstyle, percent signs
are not doubled across text(), literal_column(), and
column().
Change-Id: Ie2f278ab1dbb94b5078f85c0096d74dbfa049197
Fixes: #3740
method, and its interaction with result-row processing, now allows
the columns passed to the method to be positionally matched with the
result columns in the statement, rather than matching on name alone.
The advantage to this includes that when linking a textual SQL statement
to an ORM or Core table model, no system of labeling or de-duping of
common column names needs to occur, which also means there's no need
to worry about how label names match to ORM columns and so-forth. In
addition, the :class:`.ResultProxy` has been further enhanced to
map column and string keys to a row with greater precision in some
cases. fixes#3501
- reorganize the initialization of ResultMetaData for readability
and complexity; use the name "cursor_description", define the
task of "merging" cursor_description with compiled column information
as its own function, and also define "name extraction" as a separate task.
- fully change the name we use in the "ambiguous column" error to be the
actual name that was ambiguous, modify the C ext also
are now exercised within the normal unit test suite in both Python
2 and Python 3.
- remove the old testdocs.py runner and replace with test/base/test_tutorials.py
- use pytest's unicode fixer so that we can test for unicode strings
in both py2k/3k
- use py3k format overall for prints, exceptions
- add other fixers to guarantee deterministic results
- add skips and ellipses to outputs that aren't worth matching
statement. This feature is available by passing the
:paramref:`~.sqlalchemy.sql.expression.update.preserve_parameter_order`
flag either to the core :class:`.Update` construct or alternatively
adding it to the :paramref:`.Query.update.update_args` dictionary at
the ORM-level, also passing the parameters themselves as a list of 2-tuples.
Thanks to Gorka Eguileor for implementation and tests.
adapted from pullreq github:200
directly into the unit of work's facility for emitting INSERT
and UPDATE statements has been created. When used correctly,
this expert-oriented system can allow ORM-mappings to be used
to generate bulk insert and update statements batched into
executemany groups, allowing the statements to proceed at
speeds that rival direct use of the Core.
fixes#3100
constructs are now importable from the "from sqlalchemy" namespace,
just like every other Core construct.
- The implicit conversion of strings to :func:`.text` constructs
when passed to most builder methods of :func:`.select` as
well as :class:`.Query` now emits a warning with just the
plain string sent. The textual conversion still proceeds normally,
however. The only method that accepts a string without a warning
are the "label reference" methods like order_by(), group_by();
these functions will now at compile time attempt to resolve a single
string argument to a column or label expression present in the
selectable; if none is located, the expression still renders, but
you get the warning again. The rationale here is that the implicit
conversion from string to text is more unexpected than not these days,
and it is better that the user send more direction to the Core / ORM
when passing a raw string as to what direction should be taken.
Core/ORM tutorials have been updated to go more in depth as to how text
is handled.
fixes#2992
- add support for correlations to propagate all the way in; because
correlations require context now, need to make sure a select enclosure
of any level takes effect any number of levels deep.
- fix what we said correlate_except() was supposed to do when we first
released #2668 - "the FROM clause is left intact if the correlated SELECT
is not used in the context of an enclosing SELECT..." - it was not
considering the "existing_froms" collection at all, and prohibited
additional FROMs from being placed in an any() or has().
- add test for multilevel any()
- lots of docs, including glossary entries as we really need to define
"WHERE clause", "columns clause" etc. so that we can explain correlation better
- based on the insight that a SELECT can correlate anything that ultimately
came from an enclosing SELECT that links to this one via WHERE/columns/HAVING/ORDER BY,
have the compiler keep track of the FROM lists that correspond in this way,
link it to the asfrom flag, so that we send to _get_display_froms() the exact
list of candidate FROMs to correlate. no longer need any asfrom logic in the
Select() itself
- preserve 0.8.1's behavior for correlation when no correlate options are given, not
to mention 0.7 and prior's behavior of not propagating implicit correlation more than one level..
this is to reduce surprises/hard-to-debug situations when a user isn't trying
to correlate anything.
- remove most use of "whereclause" and "from_obj", not done yet,
part of [ticket:2679]
- add links to method chained versions for all Select.append_XYZ()
calls
- add "method chaining" and "generative" to glossary
- redefine inspect(Class.attrname).parent to be always an inspectable
target; either Mapper or AliasedInsp
- add most major features to 08 migration, document, link
to the "engines and connections" chapter nobody reads, put big green "note:"
boxes with the word "discouraged" in them for "bound metadata", "implicit execution",
"threadlocal strategy"
- epic documentation sweep for new operator system, making ORM links consistent
and complete, full documentation and examples for type/SQL expression feature
- type_coerce() explicitly accepts BindParamClause objects
- change UserDefinedType to coerce the other side to itself by default as this
is much more likely what's desired
- make coerce_compared_type() fully public on all types
- have profiling run the test no matter what so that the test_zoomarks don't fail
when callcounts are missing
Mike Bayer