test/sql/test_constraints.py

from sqlalchemy import CheckConstraint
from sqlalchemy import Column
from sqlalchemy import exc
from sqlalchemy import ForeignKey
from sqlalchemy import ForeignKeyConstraint
from sqlalchemy import func
from sqlalchemy import Index
from sqlalchemy import Integer
from sqlalchemy import MetaData
from sqlalchemy import PrimaryKeyConstraint
from sqlalchemy import schema
from sqlalchemy import String
from sqlalchemy import Table
from sqlalchemy import testing
from sqlalchemy import text
from sqlalchemy import UniqueConstraint
from sqlalchemy.engine import default
from sqlalchemy.testing import assert_raises
from sqlalchemy.testing import assert_raises_message
from sqlalchemy.testing import AssertsCompiledSQL
from sqlalchemy.testing import AssertsExecutionResults
from sqlalchemy.testing import engines
from sqlalchemy.testing import eq_
from sqlalchemy.testing import fixtures
from sqlalchemy.testing.assertions import expect_warnings
from sqlalchemy.testing.assertsql import AllOf
from sqlalchemy.testing.assertsql import CompiledSQL
from sqlalchemy.testing.assertsql import DialectSQL
from sqlalchemy.testing.assertsql import RegexSQL


class ConstraintGenTest(fixtures.TestBase, AssertsExecutionResults):
    __dialect__ = "default"
    __backend__ = True

    @testing.provide_metadata
    def test_pk_fk_constraint_create(self):
        metadata = self.metadata

        Table(
            "employees",
            metadata,
            Column("id", Integer),
            Column("soc", String(40)),
            Column("name", String(30)),
            PrimaryKeyConstraint("id", "soc"),
        )
        Table(
            "elements",
            metadata,
            Column("id", Integer),
            Column("stuff", String(30)),
            Column("emp_id", Integer),
            Column("emp_soc", String(40)),
            PrimaryKeyConstraint("id", name="elements_primkey"),
            ForeignKeyConstraint(
                ["emp_id", "emp_soc"], ["employees.id", "employees.soc"]
            ),
        )
        self.assert_sql_execution(
            testing.db,
            lambda: metadata.create_all(checkfirst=False),
            CompiledSQL(
                "CREATE TABLE employees ("
                "id INTEGER NOT NULL, "
                "soc VARCHAR(40) NOT NULL, "
                "name VARCHAR(30), "
                "PRIMARY KEY (id, soc)"
                ")"
            ),
            CompiledSQL(
                "CREATE TABLE elements ("
                "id INTEGER NOT NULL, "
                "stuff VARCHAR(30), "
                "emp_id INTEGER, "
                "emp_soc VARCHAR(40), "
                "CONSTRAINT elements_primkey PRIMARY KEY (id), "
                "FOREIGN KEY(emp_id, emp_soc) "
                "REFERENCES employees (id, soc)"
                ")"
            ),
        )

    @testing.force_drop_names("a", "b")
    def test_fk_cant_drop_cycled_unnamed(self):
        metadata = MetaData()

        Table(
            "a",
            metadata,
            Column("id", Integer, primary_key=True),
            Column("bid", Integer),
            ForeignKeyConstraint(["bid"], ["b.id"]),
        )
        Table(
            "b",
            metadata,
            Column("id", Integer, primary_key=True),
            Column("aid", Integer),
            ForeignKeyConstraint(["aid"], ["a.id"]),
        )
        metadata.create_all(testing.db)
        if testing.db.dialect.supports_alter:
            assert_raises_message(
                exc.CircularDependencyError,
                "Can't sort tables for DROP; an unresolvable foreign key "
                "dependency exists between tables: a, b.  Please ensure "
                "that the ForeignKey and ForeignKeyConstraint objects "
                "involved in the cycle have names so that they can be "
                "dropped using DROP CONSTRAINT.",
                metadata.drop_all,
                testing.db,
            )
        else:
            with expect_warnings(
                "Can't sort tables for DROP; an unresolvable "
                "foreign key dependency "
            ):
                with self.sql_execution_asserter() as asserter:
                    metadata.drop_all(testing.db, checkfirst=False)

            asserter.assert_(
                AllOf(CompiledSQL("DROP TABLE a"), CompiledSQL("DROP TABLE b"))
            )

    @testing.provide_metadata
    def test_fk_table_auto_alter_constraint_create(self):
        metadata = self.metadata

        Table(
            "a",
            metadata,
            Column("id", Integer, primary_key=True),
            Column("bid", Integer),
            ForeignKeyConstraint(["bid"], ["b.id"]),
        )
        Table(
            "b",
            metadata,
            Column("id", Integer, primary_key=True),
            Column("aid", Integer),
            ForeignKeyConstraint(["aid"], ["a.id"], name="bfk"),
        )
        self._assert_cyclic_constraint(
            metadata, auto=True, sqlite_warning=True
        )

    @testing.provide_metadata
    def test_fk_column_auto_alter_inline_constraint_create(self):
        metadata = self.metadata

        Table(
            "a",
            metadata,
            Column("id", Integer, primary_key=True),
            Column("bid", Integer, ForeignKey("b.id")),
        )
        Table(
            "b",
            metadata,
            Column("id", Integer, primary_key=True),
            Column("aid", Integer, ForeignKey("a.id", name="bfk")),
        )
        self._assert_cyclic_constraint(
            metadata, auto=True, sqlite_warning=True
        )

    @testing.provide_metadata
    def test_fk_column_use_alter_inline_constraint_create(self):
        metadata = self.metadata

        Table(
            "a",
            metadata,
            Column("id", Integer, primary_key=True),
            Column("bid", Integer, ForeignKey("b.id")),
        )
        Table(
            "b",
            metadata,
            Column("id", Integer, primary_key=True),
            Column(
                "aid", Integer, ForeignKey("a.id", name="bfk", use_alter=True)
            ),
        )
        self._assert_cyclic_constraint(metadata, auto=False)

    @testing.provide_metadata
    def test_fk_table_use_alter_constraint_create(self):
        metadata = self.metadata

        Table(
            "a",
            metadata,
            Column("id", Integer, primary_key=True),
            Column("bid", Integer),
            ForeignKeyConstraint(["bid"], ["b.id"]),
        )
        Table(
            "b",
            metadata,
            Column("id", Integer, primary_key=True),
            Column("aid", Integer),
            ForeignKeyConstraint(
                ["aid"], ["a.id"], use_alter=True, name="bfk"
            ),
        )
        self._assert_cyclic_constraint(metadata)

    @testing.provide_metadata
    def test_fk_column_use_alter_constraint_create(self):
        metadata = self.metadata

        Table(
            "a",
            metadata,
            Column("id", Integer, primary_key=True),
            Column("bid", Integer, ForeignKey("b.id")),
        )
        Table(
            "b",
            metadata,
            Column("id", Integer, primary_key=True),
            Column(
                "aid", Integer, ForeignKey("a.id", use_alter=True, name="bfk")
            ),
        )
        self._assert_cyclic_constraint(metadata, auto=False)

    def _assert_cyclic_constraint(
        self, metadata, auto=False, sqlite_warning=False
    ):
        if testing.db.dialect.supports_alter:
            self._assert_cyclic_constraint_supports_alter(metadata, auto=auto)
        else:
            self._assert_cyclic_constraint_no_alter(
                metadata, auto=auto, sqlite_warning=sqlite_warning
            )

    def _assert_cyclic_constraint_supports_alter(self, metadata, auto=False):
        table_assertions = []
        if auto:
            table_assertions = [
                CompiledSQL(
                    "CREATE TABLE b ("
                    "id INTEGER NOT NULL, "
                    "aid INTEGER, "
                    "PRIMARY KEY (id)"
                    ")"
                ),
                CompiledSQL(
                    "CREATE TABLE a ("
                    "id INTEGER NOT NULL, "
                    "bid INTEGER, "
                    "PRIMARY KEY (id)"
                    ")"
                ),
            ]
        else:
            table_assertions = [
                CompiledSQL(
                    "CREATE TABLE b ("
                    "id INTEGER NOT NULL, "
                    "aid INTEGER, "
                    "PRIMARY KEY (id)"
                    ")"
                ),
                CompiledSQL(
                    "CREATE TABLE a ("
                    "id INTEGER NOT NULL, "
                    "bid INTEGER, "
                    "PRIMARY KEY (id), "
                    "FOREIGN KEY(bid) REFERENCES b (id)"
                    ")"
                ),
            ]

        assertions = [AllOf(*table_assertions)]
        fk_assertions = []
        fk_assertions.append(
            CompiledSQL(
                "ALTER TABLE b ADD CONSTRAINT bfk "
                "FOREIGN KEY(aid) REFERENCES a (id)"
            )
        )
        if auto:
            fk_assertions.append(
                CompiledSQL(
                    "ALTER TABLE a ADD " "FOREIGN KEY(bid) REFERENCES b (id)"
                )
            )
        assertions.append(AllOf(*fk_assertions))

        with self.sql_execution_asserter() as asserter:
            metadata.create_all(checkfirst=False)
        asserter.assert_(*assertions)

        assertions = [
            CompiledSQL("ALTER TABLE b DROP CONSTRAINT bfk"),
            CompiledSQL("DROP TABLE a"),
            CompiledSQL("DROP TABLE b"),
        ]

        with self.sql_execution_asserter() as asserter:
            metadata.drop_all(checkfirst=False),
        asserter.assert_(*assertions)

    def _assert_cyclic_constraint_no_alter(
        self, metadata, auto=False, sqlite_warning=False
    ):
        table_assertions = []
        if auto:
            table_assertions.append(
                DialectSQL(
                    "CREATE TABLE b ("
                    "id INTEGER NOT NULL, "
                    "aid INTEGER, "
                    "PRIMARY KEY (id), "
                    "CONSTRAINT bfk FOREIGN KEY(aid) REFERENCES a (id)"
                    ")"
                )
            )
            table_assertions.append(
                DialectSQL(
                    "CREATE TABLE a ("
                    "id INTEGER NOT NULL, "
                    "bid INTEGER, "
                    "PRIMARY KEY (id), "
                    "FOREIGN KEY(bid) REFERENCES b (id)"
                    ")"
                )
            )
        else:
            table_assertions.append(
                DialectSQL(
                    "CREATE TABLE b ("
                    "id INTEGER NOT NULL, "
                    "aid INTEGER, "
                    "PRIMARY KEY (id), "
                    "CONSTRAINT bfk FOREIGN KEY(aid) REFERENCES a (id)"
                    ")"
                )
            )

            table_assertions.append(
                DialectSQL(
                    "CREATE TABLE a ("
                    "id INTEGER NOT NULL, "
                    "bid INTEGER, "
                    "PRIMARY KEY (id), "
                    "FOREIGN KEY(bid) REFERENCES b (id)"
                    ")"
                )
            )

        assertions = [AllOf(*table_assertions)]

        with self.sql_execution_asserter() as asserter:
            metadata.create_all(checkfirst=False)
        asserter.assert_(*assertions)

        assertions = [
            AllOf(CompiledSQL("DROP TABLE a"), CompiledSQL("DROP TABLE b"))
        ]

        if sqlite_warning:
            with expect_warnings("Can't sort tables for DROP; "):
                with self.sql_execution_asserter() as asserter:
                    metadata.drop_all(checkfirst=False),
        else:
            with self.sql_execution_asserter() as asserter:
                metadata.drop_all(checkfirst=False),
        asserter.assert_(*assertions)

    @testing.force_drop_names("a", "b")
    def test_cycle_unnamed_fks(self):
        metadata = MetaData(testing.db)

        Table(
            "a",
            metadata,
            Column("id", Integer, primary_key=True),
            Column("bid", Integer, ForeignKey("b.id")),
        )

        Table(
            "b",
            metadata,
            Column("id", Integer, primary_key=True),
            Column("aid", Integer, ForeignKey("a.id")),
        )

        assertions = [
            AllOf(
                CompiledSQL(
                    "CREATE TABLE b ("
                    "id INTEGER NOT NULL, "
                    "aid INTEGER, "
                    "PRIMARY KEY (id)"
                    ")"
                ),
                CompiledSQL(
                    "CREATE TABLE a ("
                    "id INTEGER NOT NULL, "
                    "bid INTEGER, "
                    "PRIMARY KEY (id)"
                    ")"
                ),
            ),
            AllOf(
                CompiledSQL(
                    "ALTER TABLE b ADD " "FOREIGN KEY(aid) REFERENCES a (id)"
                ),
                CompiledSQL(
                    "ALTER TABLE a ADD " "FOREIGN KEY(bid) REFERENCES b (id)"
                ),
            ),
        ]
        with self.sql_execution_asserter() as asserter:
            metadata.create_all(checkfirst=False)

        if testing.db.dialect.supports_alter:
            asserter.assert_(*assertions)

            assert_raises_message(
                exc.CircularDependencyError,
                "Can't sort tables for DROP; an unresolvable foreign key "
                "dependency exists between tables: a, b.  "
                "Please ensure that the "
                "ForeignKey and ForeignKeyConstraint objects involved in the "
                "cycle have names so that they can be dropped using "
                "DROP CONSTRAINT.",
                metadata.drop_all,
                checkfirst=False,
            )
        else:
            with expect_warnings(
                "Can't sort tables for DROP; an unresolvable "
                "foreign key dependency exists between tables"
            ):
                with self.sql_execution_asserter() as asserter:
                    metadata.drop_all(checkfirst=False)

            asserter.assert_(
                AllOf(CompiledSQL("DROP TABLE b"), CompiledSQL("DROP TABLE a"))
            )

    @testing.force_drop_names("a", "b")
    def test_cycle_named_fks(self):
        metadata = MetaData(testing.db)

        Table(
            "a",
            metadata,
            Column("id", Integer, primary_key=True),
            Column("bid", Integer, ForeignKey("b.id")),
        )

        Table(
            "b",
            metadata,
            Column("id", Integer, primary_key=True),
            Column(
                "aid",
                Integer,
                ForeignKey("a.id", use_alter=True, name="aidfk"),
            ),
        )

        assertions = [
            AllOf(
                CompiledSQL(
                    "CREATE TABLE b ("
                    "id INTEGER NOT NULL, "
                    "aid INTEGER, "
                    "PRIMARY KEY (id)"
                    ")"
                ),
                CompiledSQL(
                    "CREATE TABLE a ("
                    "id INTEGER NOT NULL, "
                    "bid INTEGER, "
                    "PRIMARY KEY (id), "
                    "FOREIGN KEY(bid) REFERENCES b (id)"
                    ")"
                ),
            ),
            CompiledSQL(
                "ALTER TABLE b ADD CONSTRAINT aidfk "
                "FOREIGN KEY(aid) REFERENCES a (id)"
            ),
        ]
        with self.sql_execution_asserter() as asserter:
            metadata.create_all(checkfirst=False)

        if testing.db.dialect.supports_alter:
            asserter.assert_(*assertions)

            with self.sql_execution_asserter() as asserter:
                metadata.drop_all(checkfirst=False)

            asserter.assert_(
                CompiledSQL("ALTER TABLE b DROP CONSTRAINT aidfk"),
                AllOf(
                    CompiledSQL("DROP TABLE b"), CompiledSQL("DROP TABLE a")
                ),
            )
        else:
            with self.sql_execution_asserter() as asserter:
                metadata.drop_all(checkfirst=False)

            asserter.assert_(
                AllOf(CompiledSQL("DROP TABLE b"), CompiledSQL("DROP TABLE a"))
            )

    @testing.requires.check_constraints
    @testing.provide_metadata
    def test_check_constraint_create(self):
        metadata = self.metadata

        Table(
            "foo",
            metadata,
            Column("id", Integer, primary_key=True),
            Column("x", Integer),
            Column("y", Integer),
            CheckConstraint("x>y"),
        )
        Table(
            "bar",
            metadata,
            Column("id", Integer, primary_key=True),
            Column("x", Integer, CheckConstraint("x>7")),
            Column("z", Integer),
        )

        self.assert_sql_execution(
            testing.db,
            lambda: metadata.create_all(checkfirst=False),
            AllOf(
                CompiledSQL(
                    "CREATE TABLE foo ("
                    "id INTEGER NOT NULL, "
                    "x INTEGER, "
                    "y INTEGER, "
                    "PRIMARY KEY (id), "
                    "CHECK (x>y)"
                    ")"
                ),
                CompiledSQL(
                    "CREATE TABLE bar ("
                    "id INTEGER NOT NULL, "
                    "x INTEGER CHECK (x>7), "
                    "z INTEGER, "
                    "PRIMARY KEY (id)"
                    ")"
                ),
            ),
        )

    @testing.provide_metadata
    def test_unique_constraint_create(self):
        metadata = self.metadata

        Table(
            "foo",
            metadata,
            Column("id", Integer, primary_key=True),
            Column("value", String(30), unique=True),
        )
        Table(
            "bar",
            metadata,
            Column("id", Integer, primary_key=True),
            Column("value", String(30)),
            Column("value2", String(30)),
            UniqueConstraint("value", "value2", name="uix1"),
        )

        self.assert_sql_execution(
            testing.db,
            lambda: metadata.create_all(checkfirst=False),
            AllOf(
                CompiledSQL(
                    "CREATE TABLE foo ("
                    "id INTEGER NOT NULL, "
                    "value VARCHAR(30), "
                    "PRIMARY KEY (id), "
                    "UNIQUE (value)"
                    ")"
                ),
                CompiledSQL(
                    "CREATE TABLE bar ("
                    "id INTEGER NOT NULL, "
                    "value VARCHAR(30), "
                    "value2 VARCHAR(30), "
                    "PRIMARY KEY (id), "
                    "CONSTRAINT uix1 UNIQUE (value, value2)"
                    ")"
                ),
            ),
        )

    @testing.provide_metadata
    def test_index_create(self):
        metadata = self.metadata

        employees = Table(
            "employees",
            metadata,
            Column("id", Integer, primary_key=True),
            Column("first_name", String(30)),
            Column("last_name", String(30)),
            Column("email_address", String(30)),
        )

        i = Index(
            "employee_name_index",
            employees.c.last_name,
            employees.c.first_name,
        )
        assert i in employees.indexes

        i2 = Index(
            "employee_email_index", employees.c.email_address, unique=True
        )
        assert i2 in employees.indexes

        self.assert_sql_execution(
            testing.db,
            lambda: metadata.create_all(checkfirst=False),
            RegexSQL("^CREATE TABLE"),
            AllOf(
                CompiledSQL(
                    "CREATE INDEX employee_name_index ON "
                    "employees (last_name, first_name)",
                    [],
                ),
                CompiledSQL(
                    "CREATE UNIQUE INDEX employee_email_index ON "
                    "employees (email_address)",
                    [],
                ),
            ),
        )

    @testing.provide_metadata
    def test_index_create_camelcase(self):
        """test that mixed-case index identifiers are legal"""

        metadata = self.metadata

        employees = Table(
            "companyEmployees",
            metadata,
            Column("id", Integer, primary_key=True),
            Column("firstName", String(30)),
            Column("lastName", String(30)),
            Column("emailAddress", String(30)),
        )

        Index("employeeNameIndex", employees.c.lastName, employees.c.firstName)

        Index("employeeEmailIndex", employees.c.emailAddress, unique=True)

        self.assert_sql_execution(
            testing.db,
            lambda: metadata.create_all(checkfirst=False),
            RegexSQL("^CREATE TABLE"),
            AllOf(
                CompiledSQL(
                    'CREATE INDEX "employeeNameIndex" ON '
                    '"companyEmployees" ("lastName", "firstName")',
                    [],
                ),
                CompiledSQL(
                    'CREATE UNIQUE INDEX "employeeEmailIndex" ON '
                    '"companyEmployees" ("emailAddress")',
                    [],
                ),
            ),
        )

    @testing.provide_metadata
    def test_index_create_inline(self):
        # test an index create using index=True, unique=True

        metadata = self.metadata

        events = Table(
            "events",
            metadata,
            Column("id", Integer, primary_key=True),
            Column("name", String(30), index=True, unique=True),
            Column("location", String(30), index=True),
            Column("sport", String(30)),
            Column("announcer", String(30)),
            Column("winner", String(30)),
        )

        Index(
            "sport_announcer", events.c.sport, events.c.announcer, unique=True
        )
        Index("idx_winners", events.c.winner)

        eq_(
            set(ix.name for ix in events.indexes),
            set(
                [
                    "ix_events_name",
                    "ix_events_location",
                    "sport_announcer",
                    "idx_winners",
                ]
            ),
        )

        self.assert_sql_execution(
            testing.db,
            lambda: events.create(testing.db),
            RegexSQL("^CREATE TABLE events"),
            AllOf(
                CompiledSQL(
                    "CREATE UNIQUE INDEX ix_events_name ON events " "(name)"
                ),
                CompiledSQL(
                    "CREATE INDEX ix_events_location ON events " "(location)"
                ),
                CompiledSQL(
                    "CREATE UNIQUE INDEX sport_announcer ON events "
                    "(sport, announcer)"
                ),
                CompiledSQL("CREATE INDEX idx_winners ON events (winner)"),
            ),
        )

    @testing.provide_metadata
    def test_index_functional_create(self):
        metadata = self.metadata

        t = Table(
            "sometable",
            metadata,
            Column("id", Integer, primary_key=True),
            Column("data", String(50)),
        )
        Index("myindex", t.c.data.desc())
        self.assert_sql_execution(
            testing.db,
            lambda: t.create(testing.db),
            CompiledSQL(
                "CREATE TABLE sometable (id INTEGER NOT NULL, "
                "data VARCHAR(50), PRIMARY KEY (id))"
            ),
            CompiledSQL("CREATE INDEX myindex ON sometable (data DESC)"),
        )


class ConstraintCompilationTest(fixtures.TestBase, AssertsCompiledSQL):
    __dialect__ = "default"

    def test_create_index_plain(self):
        t = Table("t", MetaData(), Column("x", Integer))
        i = Index("xyz", t.c.x)
        self.assert_compile(schema.CreateIndex(i), "CREATE INDEX xyz ON t (x)")

    def test_drop_index_plain_unattached(self):
        self.assert_compile(
            schema.DropIndex(Index(name="xyz")), "DROP INDEX xyz"
        )

    def test_drop_index_plain(self):
        self.assert_compile(
            schema.DropIndex(Index(name="xyz")), "DROP INDEX xyz"
        )

    def test_create_index_schema(self):
        t = Table("t", MetaData(), Column("x", Integer), schema="foo")
        i = Index("xyz", t.c.x)
        self.assert_compile(
            schema.CreateIndex(i), "CREATE INDEX xyz ON foo.t (x)"
        )

    def test_drop_index_schema(self):
        t = Table("t", MetaData(), Column("x", Integer), schema="foo")
        i = Index("xyz", t.c.x)
        self.assert_compile(schema.DropIndex(i), "DROP INDEX foo.xyz")

    def test_too_long_index_name(self):
        dialect = testing.db.dialect.__class__()

        for max_ident, max_index in [(22, None), (256, 22)]:
            dialect.max_identifier_length = max_ident
            dialect.max_index_name_length = max_index

            for tname, cname, exp in [
                ("sometable", "this_name_is_too_long", "ix_sometable_t_09aa"),
                ("sometable", "this_name_alsois_long", "ix_sometable_t_3cf1"),
            ]:

                t1 = Table(
                    tname, MetaData(), Column(cname, Integer, index=True)
                )
                ix1 = list(t1.indexes)[0]

                self.assert_compile(
                    schema.CreateIndex(ix1),
                    "CREATE INDEX %s " "ON %s (%s)" % (exp, tname, cname),
                    dialect=dialect,
                )

        dialect.max_identifier_length = 22
        dialect.max_index_name_length = None

        t1 = Table("t", MetaData(), Column("c", Integer))
        assert_raises(
            exc.IdentifierError,
            schema.CreateIndex(
                Index(
                    "this_other_name_is_too_long_for_what_were_doing", t1.c.c
                )
            ).compile,
            dialect=dialect,
        )

    def test_functional_index(self):
        metadata = MetaData()
        x = Table("x", metadata, Column("q", String(50)))
        idx = Index("y", func.lower(x.c.q))

        self.assert_compile(
            schema.CreateIndex(idx), "CREATE INDEX y ON x (lower(q))"
        )

        self.assert_compile(
            schema.CreateIndex(idx),
            "CREATE INDEX y ON x (lower(q))",
            dialect=testing.db.dialect,
        )

    def test_index_against_text_separate(self):
        metadata = MetaData()
        idx = Index("y", text("some_function(q)"))
        t = Table("x", metadata, Column("q", String(50)))
        t.append_constraint(idx)
        self.assert_compile(
            schema.CreateIndex(idx), "CREATE INDEX y ON x (some_function(q))"
        )

    def test_index_against_text_inline(self):
        metadata = MetaData()
        idx = Index("y", text("some_function(q)"))
        x = Table("x", metadata, Column("q", String(50)), idx)

        self.assert_compile(
            schema.CreateIndex(idx), "CREATE INDEX y ON x (some_function(q))"
        )

    def test_index_declaration_inline(self):
        metadata = MetaData()

        t1 = Table(
            "t1",
            metadata,
            Column("x", Integer),
            Column("y", Integer),
            Index("foo", "x", "y"),
        )
        self.assert_compile(
            schema.CreateIndex(list(t1.indexes)[0]),
            "CREATE INDEX foo ON t1 (x, y)",
        )

    def _test_deferrable(self, constraint_factory):
        dialect = default.DefaultDialect()

        t = Table(
            "tbl",
            MetaData(),
            Column("a", Integer),
            Column("b", Integer),
            constraint_factory(deferrable=True),
        )

        sql = str(schema.CreateTable(t).compile(dialect=dialect))
        assert "DEFERRABLE" in sql, sql
        assert "NOT DEFERRABLE" not in sql, sql

        t = Table(
            "tbl",
            MetaData(),
            Column("a", Integer),
            Column("b", Integer),
            constraint_factory(deferrable=False),
        )

        sql = str(schema.CreateTable(t).compile(dialect=dialect))
        assert "NOT DEFERRABLE" in sql

        t = Table(
            "tbl",
            MetaData(),
            Column("a", Integer),
            Column("b", Integer),
            constraint_factory(deferrable=True, initially="IMMEDIATE"),
        )
        sql = str(schema.CreateTable(t).compile(dialect=dialect))
        assert "NOT DEFERRABLE" not in sql
        assert "INITIALLY IMMEDIATE" in sql

        t = Table(
            "tbl",
            MetaData(),
            Column("a", Integer),
            Column("b", Integer),
            constraint_factory(deferrable=True, initially="DEFERRED"),
        )
        sql = str(schema.CreateTable(t).compile(dialect=dialect))

        assert "NOT DEFERRABLE" not in sql
        assert "INITIALLY DEFERRED" in sql

    def test_column_level_ck_name(self):
        t = Table(
            "tbl",
            MetaData(),
            Column(
                "a",
                Integer,
                CheckConstraint("a > 5", name="ck_a_greater_five"),
            ),
        )
        self.assert_compile(
            schema.CreateTable(t),
            "CREATE TABLE tbl (a INTEGER CONSTRAINT "
            "ck_a_greater_five CHECK (a > 5))",
        )

    def test_deferrable_pk(self):
        def factory(**kw):
            return PrimaryKeyConstraint("a", **kw)

        self._test_deferrable(factory)

    def test_deferrable_table_fk(self):
        def factory(**kw):
            return ForeignKeyConstraint(["b"], ["tbl.a"], **kw)

        self._test_deferrable(factory)

    def test_deferrable_column_fk(self):
        t = Table(
            "tbl",
            MetaData(),
            Column("a", Integer),
            Column(
                "b",
                Integer,
                ForeignKey("tbl.a", deferrable=True, initially="DEFERRED"),
            ),
        )

        self.assert_compile(
            schema.CreateTable(t),
            "CREATE TABLE tbl (a INTEGER, b INTEGER, "
            "FOREIGN KEY(b) REFERENCES tbl "
            "(a) DEFERRABLE INITIALLY DEFERRED)",
        )

    def test_fk_match_clause(self):
        t = Table(
            "tbl",
            MetaData(),
            Column("a", Integer),
            Column("b", Integer, ForeignKey("tbl.a", match="SIMPLE")),
        )

        self.assert_compile(
            schema.CreateTable(t),
            "CREATE TABLE tbl (a INTEGER, b INTEGER, "
            "FOREIGN KEY(b) REFERENCES tbl "
            "(a) MATCH SIMPLE)",
        )

        self.assert_compile(
            schema.AddConstraint(list(t.foreign_keys)[0].constraint),
            "ALTER TABLE tbl ADD FOREIGN KEY(b) "
            "REFERENCES tbl (a) MATCH SIMPLE",
        )

    def test_create_table_omit_fks(self):
        fkcs = [
            ForeignKeyConstraint(["a"], ["remote.id"], name="foo"),
            ForeignKeyConstraint(["b"], ["remote.id"], name="bar"),
            ForeignKeyConstraint(["c"], ["remote.id"], name="bat"),
        ]
        m = MetaData()
        t = Table(
            "t",
            m,
            Column("a", Integer),
            Column("b", Integer),
            Column("c", Integer),
            *fkcs
        )
        Table("remote", m, Column("id", Integer, primary_key=True))

        self.assert_compile(
            schema.CreateTable(t, include_foreign_key_constraints=[]),
            "CREATE TABLE t (a INTEGER, b INTEGER, c INTEGER)",
        )
        self.assert_compile(
            schema.CreateTable(t, include_foreign_key_constraints=fkcs[0:2]),
            "CREATE TABLE t (a INTEGER, b INTEGER, c INTEGER, "
            "CONSTRAINT foo FOREIGN KEY(a) REFERENCES remote (id), "
            "CONSTRAINT bar FOREIGN KEY(b) REFERENCES remote (id))",
        )

    def test_deferrable_unique(self):
        def factory(**kw):
            return UniqueConstraint("b", **kw)

        self._test_deferrable(factory)

    def test_deferrable_table_check(self):
        def factory(**kw):
            return CheckConstraint("a < b", **kw)

        self._test_deferrable(factory)

    def test_multiple(self):
        m = MetaData()
        Table(
            "foo",
            m,
            Column("id", Integer, primary_key=True),
            Column("bar", Integer, primary_key=True),
        )
        tb = Table(
            "some_table",
            m,
            Column("id", Integer, primary_key=True),
            Column("foo_id", Integer, ForeignKey("foo.id")),
            Column("foo_bar", Integer, ForeignKey("foo.bar")),
        )
        self.assert_compile(
            schema.CreateTable(tb),
            "CREATE TABLE some_table ("
            "id INTEGER NOT NULL, "
            "foo_id INTEGER, "
            "foo_bar INTEGER, "
            "PRIMARY KEY (id), "
            "FOREIGN KEY(foo_id) REFERENCES foo (id), "
            "FOREIGN KEY(foo_bar) REFERENCES foo (bar))",
        )

    def test_empty_pkc(self):
        # test that an empty primary key is ignored
        metadata = MetaData()
        tbl = Table(
            "test",
            metadata,
            Column("x", Integer, autoincrement=False),
            Column("y", Integer, autoincrement=False),
            PrimaryKeyConstraint(),
        )
        self.assert_compile(
            schema.CreateTable(tbl), "CREATE TABLE test (x INTEGER, y INTEGER)"
        )

    def test_empty_uc(self):
        # test that an empty constraint is ignored
        metadata = MetaData()
        tbl = Table(
            "test",
            metadata,
            Column("x", Integer, autoincrement=False),
            Column("y", Integer, autoincrement=False),
            UniqueConstraint(),
        )
        self.assert_compile(
            schema.CreateTable(tbl), "CREATE TABLE test (x INTEGER, y INTEGER)"
        )

    def test_deferrable_column_check(self):
        t = Table(
            "tbl",
            MetaData(),
            Column("a", Integer),
            Column(
                "b",
                Integer,
                CheckConstraint(
                    "a < b", deferrable=True, initially="DEFERRED"
                ),
            ),
        )

        self.assert_compile(
            schema.CreateTable(t),
            "CREATE TABLE tbl (a INTEGER, b INTEGER CHECK (a < b) "
            "DEFERRABLE INITIALLY DEFERRED)",
        )

    def test_use_alter(self):
        m = MetaData()
        Table("t", m, Column("a", Integer))

        Table(
            "t2",
            m,
            Column(
                "a", Integer, ForeignKey("t.a", use_alter=True, name="fk_ta")
            ),
            Column("b", Integer, ForeignKey("t.a", name="fk_tb")),
        )

        e = engines.mock_engine(dialect_name="postgresql")
        m.create_all(e)
        m.drop_all(e)

        e.assert_sql(
            [
                "CREATE TABLE t (a INTEGER)",
                "CREATE TABLE t2 (a INTEGER, b INTEGER, CONSTRAINT fk_tb "
                "FOREIGN KEY(b) REFERENCES t (a))",
                "ALTER TABLE t2 "
                "ADD CONSTRAINT fk_ta FOREIGN KEY(a) REFERENCES t (a)",
                "ALTER TABLE t2 DROP CONSTRAINT fk_ta",
                "DROP TABLE t2",
                "DROP TABLE t",
            ]
        )

    def _constraint_create_fixture(self):
        m = MetaData()

        t = Table("tbl", m, Column("a", Integer), Column("b", Integer))

        t2 = Table("t2", m, Column("a", Integer), Column("b", Integer))

        return t, t2

    def test_render_ck_constraint_inline(self):
        t, t2 = self._constraint_create_fixture()

        CheckConstraint(
            "a < b",
            name="my_test_constraint",
            deferrable=True,
            initially="DEFERRED",
            table=t,
        )

        # before we create an AddConstraint,
        # the CONSTRAINT comes out inline
        self.assert_compile(
            schema.CreateTable(t),
            "CREATE TABLE tbl ("
            "a INTEGER, "
            "b INTEGER, "
            "CONSTRAINT my_test_constraint CHECK (a < b) "
            "DEFERRABLE INITIALLY DEFERRED"
            ")",
        )

    def test_render_ck_constraint_external(self):
        t, t2 = self._constraint_create_fixture()

        constraint = CheckConstraint(
            "a < b",
            name="my_test_constraint",
            deferrable=True,
            initially="DEFERRED",
            table=t,
        )

        self.assert_compile(
            schema.AddConstraint(constraint),
            "ALTER TABLE tbl ADD CONSTRAINT my_test_constraint "
            "CHECK (a < b) DEFERRABLE INITIALLY DEFERRED",
        )

    def test_external_ck_constraint_cancels_internal(self):
        t, t2 = self._constraint_create_fixture()

        constraint = CheckConstraint(
            "a < b",
            name="my_test_constraint",
            deferrable=True,
            initially="DEFERRED",
            table=t,
        )

        schema.AddConstraint(constraint)

        # once we make an AddConstraint,
        # inline compilation of the CONSTRAINT
        # is disabled
        self.assert_compile(
            schema.CreateTable(t),
            "CREATE TABLE tbl (" "a INTEGER, " "b INTEGER" ")",
        )

    def test_render_drop_constraint(self):
        t, t2 = self._constraint_create_fixture()

        constraint = CheckConstraint(
            "a < b",
            name="my_test_constraint",
            deferrable=True,
            initially="DEFERRED",
            table=t,
        )

        self.assert_compile(
            schema.DropConstraint(constraint),
            "ALTER TABLE tbl DROP CONSTRAINT my_test_constraint",
        )

    def test_render_drop_constraint_cascade(self):
        t, t2 = self._constraint_create_fixture()

        constraint = CheckConstraint(
            "a < b",
            name="my_test_constraint",
            deferrable=True,
            initially="DEFERRED",
            table=t,
        )

        self.assert_compile(
            schema.DropConstraint(constraint, cascade=True),
            "ALTER TABLE tbl DROP CONSTRAINT my_test_constraint CASCADE",
        )

    def test_render_add_fk_constraint_stringcol(self):
        t, t2 = self._constraint_create_fixture()

        constraint = ForeignKeyConstraint(["b"], ["t2.a"])
        t.append_constraint(constraint)
        self.assert_compile(
            schema.AddConstraint(constraint),
            "ALTER TABLE tbl ADD FOREIGN KEY(b) REFERENCES t2 (a)",
        )

    def test_render_add_fk_constraint_realcol(self):
        t, t2 = self._constraint_create_fixture()

        constraint = ForeignKeyConstraint([t.c.a], [t2.c.b])
        t.append_constraint(constraint)
        self.assert_compile(
            schema.AddConstraint(constraint),
            "ALTER TABLE tbl ADD FOREIGN KEY(a) REFERENCES t2 (b)",
        )

    def test_render_add_uq_constraint_stringcol(self):
        t, t2 = self._constraint_create_fixture()

        constraint = UniqueConstraint("a", "b", name="uq_cst")
        t2.append_constraint(constraint)
        self.assert_compile(
            schema.AddConstraint(constraint),
            "ALTER TABLE t2 ADD CONSTRAINT uq_cst UNIQUE (a, b)",
        )

    def test_render_add_uq_constraint_realcol(self):
        t, t2 = self._constraint_create_fixture()

        constraint = UniqueConstraint(t2.c.a, t2.c.b, name="uq_cs2")
        self.assert_compile(
            schema.AddConstraint(constraint),
            "ALTER TABLE t2 ADD CONSTRAINT uq_cs2 UNIQUE (a, b)",
        )

    def test_render_add_pk_constraint(self):
        t, t2 = self._constraint_create_fixture()

        assert t.c.a.primary_key is False
        constraint = PrimaryKeyConstraint(t.c.a)
        assert t.c.a.primary_key is True
        self.assert_compile(
            schema.AddConstraint(constraint),
            "ALTER TABLE tbl ADD PRIMARY KEY (a)",
        )

    def test_render_check_constraint_sql_literal(self):
        t, t2 = self._constraint_create_fixture()

        constraint = CheckConstraint(t.c.a > 5)

        self.assert_compile(
            schema.AddConstraint(constraint),
            "ALTER TABLE tbl ADD CHECK (a > 5)",
        )

    def test_render_check_constraint_inline_sql_literal(self):
        t, t2 = self._constraint_create_fixture()

        m = MetaData()
        t = Table(
            "t",
            m,
            Column("a", Integer, CheckConstraint(Column("a", Integer) > 5)),
        )

        self.assert_compile(
            schema.CreateColumn(t.c.a), "a INTEGER CHECK (a > 5)"
        )

    def test_render_index_sql_literal(self):
        t, t2 = self._constraint_create_fixture()

        constraint = Index("name", t.c.a + 5)

        self.assert_compile(
            schema.CreateIndex(constraint), "CREATE INDEX name ON tbl (a + 5)"
        )