How to use alembic - 10 common examples

def downgrade():
    op.drop_column('updates', 'date_testing')
    op.drop_column('updates', 'date_stable')

def upgrade():
    op.alter_column(
        'profile',
        'latest_submission_time',
        new_column_name='latest_submission_time_old',
    )
    op.add_column(
        'profile',
        sa.Column('latest_submission_time', libweasyl.models.helpers.ArrowColumn(), nullable=False, server_default='epoch'),
    )
    op.execute(
        "UPDATE profile SET latest_submission_time = TIMESTAMP WITHOUT TIME ZONE 'epoch' + "
        "(latest_submission_time_old - %d) * INTERVAL '1 second'" % (UNIXTIME_OFFSET,))
    op.drop_column('profile', 'latest_submission_time_old')

def test_uq_added_schema(self):
        m1 = MetaData()
        m2 = MetaData()
        Table("add_uq", m1, Column("x", String(50)), schema="test_schema")
        Table(
            "add_uq",
            m2,
            Column("x", String(50)),
            UniqueConstraint("x", name="ix_1"),
            schema="test_schema",
        )

        diffs = self._fixture(m1, m2, include_schemas=True)
        eq_(diffs[0][0], "add_constraint")
        eq_(diffs[0][1].name, "ix_1")

def test_config_explicit_version_table_name(self):
        context = self.make_one(
            dialect_name="sqlite", opts={"version_table": "explicit"}
        )
        eq_(context._version.name, "explicit")
        eq_(context._version.primary_key.name, "explicit_pkc")

rev.module.upgrade_engine2()
            eq_(
                op_mock.mock_calls[-1],
                mock.call.create_table("e2t1", mock.ANY),
            )
            rev.module.upgrade_engine3()
            eq_(
                op_mock.mock_calls[-1],
                mock.call.create_table("e3t1", mock.ANY),
            )
            rev.module.downgrade_engine1()
            eq_(op_mock.mock_calls[-1], mock.call.drop_table("e1t1"))
            rev.module.downgrade_engine2()
            eq_(op_mock.mock_calls[-1], mock.call.drop_table("e2t1"))
            rev.module.downgrade_engine3()
            eq_(op_mock.mock_calls[-1], mock.call.drop_table("e3t1"))

eq_(diffs[1][0], "remove_table")
        eq_(diffs[1][1].name, "extra")

        eq_(diffs[2][0], "add_column")
        eq_(diffs[2][1], "test_schema")
        eq_(diffs[2][2], "address")
        eq_(diffs[2][3], metadata.tables["test_schema.address"].c.street)

        eq_(diffs[3][0], "add_constraint")
        eq_(diffs[3][1].name, "uq_email")

        eq_(diffs[4][0], "add_column")
        eq_(diffs[4][1], "test_schema")
        eq_(diffs[4][2], "order")
        eq_(diffs[4][3], metadata.tables["test_schema.order"].c.user_id)

        eq_(diffs[5][0][0], "modify_nullable")
        eq_(diffs[5][0][5], False)
        eq_(diffs[5][0][6], True)

def test_get_heads_offline(self):
        version_table.create(self.connection)
        context = self.make_one(
            connection=self.connection,
            opts={
                "starting_rev": "q",
                "version_table": "version_table",
                "as_sql": True,
            },
        )
        eq_(context.get_current_heads(), ("q",))

Column("a1", String(10), server_default="x"),
        )

        Table(
            "user",
            m2,
            Column("id", Integer, primary_key=True),
            Column("name", String(50), nullable=False),
            Column("a1", String(10), server_default="x"),
            UniqueConstraint("name", name="uq_user_name"),
        )

        diffs = self._fixture(m1, m2)

        if self.reports_unique_constraints:
            eq_(diffs[0][0], "add_constraint")
            eq_(diffs[0][1].name, "uq_user_name")

            eq_(diffs[1][0], "remove_index")
            eq_(diffs[1][1].name, "ix_user_name")
        else:
            eq_(diffs[0][0], "remove_index")
            eq_(diffs[0][1].name, "ix_user_name")

def test_config_file_env_variable_c_override(self):
        os.environ["ALEMBIC_CONFIG"] = "/foo/bar/bat.conf"
        cl = config.CommandLine()
        with mock.patch.object(cl, "run_cmd") as run_cmd:
            cl.main(argv=["-c", "myconf.conf", "list_templates"])

        cfg = run_cmd.mock_calls[0][1][0]
        eq_(cfg.config_file_name, "myconf.conf")

with op.batch_alter_table('user', schema=None) as batch_op:
        batch_op.alter_column('a1',
               existing_type=sa.TEXT(),
               server_default='x',
               existing_nullable=True)
        batch_op.alter_column('name',
               existing_type=sa.VARCHAR(length=50),
               nullable=False)
        batch_op.drop_index('pw_idx')
        batch_op.drop_column('pw')

    # ### end Alembic commands ###""",  # noqa,
        )

        eq_(
            re.sub(r"u'", "'", template_args["downgrades"]),
            """# ### commands auto generated by Alembic - please adjust! ###
    with op.batch_alter_table('user', schema=None) as batch_op: