Files
sqlalchemy/test/sql/test_identity_column.py
T
Federico Caselli 26e8d3b5bd Add support for identity columns
Added the :class:`_schema.Identity` construct that can be used to
configure identity columns rendered with GENERATED { ALWAYS |
BY DEFAULT } AS IDENTITY. Currently the supported backends are
PostgreSQL >= 10, Oracle >= 12 and MSSQL (with different syntax
and a subset of functionalities).

Fixes: #5362
Fixes: #5324
Fixes: #5360

Change-Id: Iecea6f3ceb36821e8b96f0b61049b580507a1875
2020-08-19 00:34:23 +02:00

240 lines
7.3 KiB
Python

import re
from sqlalchemy import Column
from sqlalchemy import Identity
from sqlalchemy import Integer
from sqlalchemy import MetaData
from sqlalchemy import Sequence
from sqlalchemy import Table
from sqlalchemy import testing
from sqlalchemy.exc import ArgumentError
from sqlalchemy.schema import CreateTable
from sqlalchemy.testing import assert_raises_message
from sqlalchemy.testing import fixtures
from sqlalchemy.testing import is_
from sqlalchemy.testing import is_not_
class _IdentityDDLFixture(testing.AssertsCompiledSQL):
__backend__ = True
@testing.combinations(
(dict(always=True), "ALWAYS AS IDENTITY"),
(
dict(always=False, start=5),
"BY DEFAULT AS IDENTITY (START WITH 5)",
),
(
dict(always=True, increment=2),
"ALWAYS AS IDENTITY (INCREMENT BY 2)",
),
(
dict(increment=2, start=5),
"BY DEFAULT AS IDENTITY (INCREMENT BY 2 START WITH 5)",
),
(
dict(always=True, increment=2, start=0, minvalue=0),
"ALWAYS AS IDENTITY (INCREMENT BY 2 START WITH 0 MINVALUE 0)",
),
(
dict(always=False, increment=2, start=1, maxvalue=5),
"BY DEFAULT AS IDENTITY (INCREMENT BY 2 START WITH 1 MAXVALUE 5)",
),
(
dict(always=True, increment=2, start=1, nomaxvalue=True),
"ALWAYS AS IDENTITY (INCREMENT BY 2 START WITH 1 NO MAXVALUE)",
),
(
dict(always=False, increment=2, start=0, nominvalue=True),
"BY DEFAULT AS IDENTITY "
"(INCREMENT BY 2 START WITH 0 NO MINVALUE)",
),
(
dict(always=True, start=1, maxvalue=10, cycle=True),
"ALWAYS AS IDENTITY (START WITH 1 MAXVALUE 10 CYCLE)",
),
(
dict(always=False, cache=1000, order=True),
"BY DEFAULT AS IDENTITY (CACHE 1000 ORDER)",
),
(dict(order=True), "BY DEFAULT AS IDENTITY (ORDER)",),
)
def test_create_ddl(self, identity_args, text):
t = Table(
"foo_table",
MetaData(),
Column("foo", Integer(), Identity(**identity_args)),
)
self.assert_compile(
CreateTable(t),
"CREATE TABLE foo_table (foo INTEGER GENERATED %s)" % text,
)
t2 = t.to_metadata(MetaData())
self.assert_compile(
CreateTable(t2),
"CREATE TABLE foo_table (foo INTEGER GENERATED %s)" % text,
)
def test_other_options(self):
t = Table(
"foo_table",
MetaData(),
Column(
"foo",
Integer(),
Identity(always=True, start=3),
nullable=False,
unique=True,
),
)
self.assert_compile(
CreateTable(t),
"CREATE TABLE foo_table ("
"foo INTEGER GENERATED ALWAYS AS IDENTITY (START "
"WITH 3) NOT NULL, UNIQUE (foo))",
)
def test_autoincrement_true(self):
t = Table(
"foo_table",
MetaData(),
Column(
"foo",
Integer(),
Identity(always=True, start=3),
primary_key=True,
autoincrement=True,
),
)
self.assert_compile(
CreateTable(t),
"CREATE TABLE foo_table ("
"foo INTEGER GENERATED ALWAYS AS IDENTITY (START WITH 3) NOT NULL"
", PRIMARY KEY (foo))",
)
class IdentityDDL(_IdentityDDLFixture, fixtures.TestBase):
# this uses the connection dialect
__requires__ = ("identity_columns_standard",)
def test_on_null(self):
t = Table(
"foo_table",
MetaData(),
Column(
"foo",
Integer(),
Identity(always=False, on_null=True, start=42, order=True),
),
)
text = " ON NULL" if testing.against("oracle") else ""
self.assert_compile(
CreateTable(t),
(
"CREATE TABLE foo_table (foo INTEGER GENERATED BY DEFAULT"
+ text
+ " AS IDENTITY (START WITH 42 ORDER))"
),
)
class DefaultDialectIdentityDDL(_IdentityDDLFixture, fixtures.TestBase):
# this uses the default dialect
__dialect__ = "default"
class NotSupportingIdentityDDL(testing.AssertsCompiledSQL, fixtures.TestBase):
@testing.skip_if(testing.requires.identity_columns)
def test_identity_is_ignored(self):
t = Table(
"foo_table",
MetaData(),
Column("foo", Integer(), Identity("always", start=3)),
)
t2 = Table("foo_table", MetaData(), Column("foo", Integer()),)
exp = CreateTable(t2).compile(dialect=testing.db.dialect)
self.assert_compile(
CreateTable(t), re.sub(r"[\n\t]", "", str(exp)),
)
class IdentityTest(fixtures.TestBase):
def test_server_default_onupdate(self):
text = (
"A column with an Identity object cannot specify a "
"server_default or a server_onupdate argument"
)
def fn(**kwargs):
Table(
"t", MetaData(), Column("y", Integer, Identity(), **kwargs),
)
assert_raises_message(ArgumentError, text, fn, server_default="42")
assert_raises_message(ArgumentError, text, fn, server_onupdate="42")
def test_to_metadata(self):
identity1 = Identity("by default", on_null=True, start=123)
m = MetaData()
t = Table(
"t", m, Column("x", Integer), Column("y", Integer, identity1)
)
is_(identity1.column, t.c.y)
# is_(t.c.y.server_onupdate, identity1)
is_(t.c.y.server_default, identity1)
m2 = MetaData()
t2 = t.to_metadata(m2)
identity2 = t2.c.y.server_default
is_not_(identity1, identity2)
is_(identity1.column, t.c.y)
# is_(t.c.y.server_onupdate, identity1)
is_(t.c.y.server_default, identity1)
is_(identity2.column, t2.c.y)
# is_(t2.c.y.server_onupdate, identity2)
is_(t2.c.y.server_default, identity2)
def test_autoincrement_column(self):
t = Table(
"t",
MetaData(),
Column("y", Integer, Identity(), primary_key=True),
)
assert t._autoincrement_column is t.c.y
t2 = Table("t2", MetaData(), Column("y", Integer, Identity()))
assert t2._autoincrement_column is None
def test_identity_and_sequence(self):
def go():
return Table(
"foo_table",
MetaData(),
Column("foo", Integer(), Identity(), Sequence("foo_seq")),
)
assert_raises_message(
ArgumentError,
"An column cannot specify both Identity and Sequence.",
go,
)
def test_identity_autoincrement_false(self):
def go():
return Table(
"foo_table",
MetaData(),
Column("foo", Integer(), Identity(), autoincrement=False),
)
assert_raises_message(
ArgumentError,
"A column with an Identity object cannot specify "
"autoincrement=False",
go,
)