def test_add_drop_constraint(self):
m = MetaData()
t = Table('tbl', m, Column('a', Integer), Column('b', Integer))
t2 = Table('t2', m, Column('a', Integer), Column('b', Integer))
constraint = 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"
")")
self.assert_compile(
schema.AddConstraint(constraint),
"ALTER TABLE tbl ADD CONSTRAINT my_test_constraint "
"CHECK (a < b) DEFERRABLE INITIALLY DEFERRED")
# 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"
")")
self.assert_compile(
schema.DropConstraint(constraint),
"ALTER TABLE tbl DROP CONSTRAINT my_test_constraint")
self.assert_compile(
schema.DropConstraint(constraint, cascade=True),
"ALTER TABLE tbl DROP CONSTRAINT my_test_constraint CASCADE")
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)")
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)")
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)")
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)")
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 drop_constraint(self, const):
self._exec(schema.DropConstraint(const))
def drop_constraint(self, const: "Constraint") -> None:
self._exec(schema.DropConstraint(const))
