def downgrade()

in superset/migrations/versions/2020-10-05_18-10_af30ca79208f_collapse_alerting_models_into_a_single_.py [0:0]

• 135 lines of code
• 5 McCabe index (conditional complexity)

def downgrade():
    bind = op.get_bind()
    insp = sa.engine.reflection.Inspector.from_engine(bind)

    create_table(
        "sql_observers",
        sa.Column("created_on", sa.DateTime(), nullable=True),
        sa.Column("changed_on", sa.DateTime(), nullable=True),
        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
        sa.Column("sql", sa.Text(), nullable=False),
        sa.Column("created_by_fk", sa.Integer(), autoincrement=False, nullable=True),
        sa.Column("changed_by_fk", sa.Integer(), autoincrement=False, nullable=True),
        sa.Column("alert_id", sa.Integer(), autoincrement=False, nullable=False),
        sa.Column("database_id", sa.Integer(), autoincrement=False, nullable=False),
        sa.ForeignKeyConstraint(["alert_id"], ["alerts.id"]),
        sa.ForeignKeyConstraint(["changed_by_fk"], ["ab_user.id"]),
        sa.ForeignKeyConstraint(["created_by_fk"], ["ab_user.id"]),
        sa.ForeignKeyConstraint(["database_id"], ["dbs.id"]),
        sa.PrimaryKeyConstraint("id"),
    )

    create_table(
        "alert_validators",
        sa.Column("created_on", sa.DateTime(), nullable=True),
        sa.Column("changed_on", sa.DateTime(), nullable=True),
        sa.Column("id", sa.Integer(), autoincrement=True, nullable=False),
        sa.Column(
            "validator_type",
            sa.String(length=100),
            nullable=False,
        ),
        sa.Column("config", sa.Text(), nullable=True),
        sa.Column("created_by_fk", sa.Integer(), autoincrement=False, nullable=True),
        sa.Column("changed_by_fk", sa.Integer(), autoincrement=False, nullable=True),
        sa.Column("alert_id", sa.Integer(), autoincrement=False, nullable=False),
        sa.ForeignKeyConstraint(
            ["alert_id"], ["alerts.id"], name="alert_validators_ibfk_1"
        ),
        sa.ForeignKeyConstraint(
            ["changed_by_fk"], ["ab_user.id"], name="alert_validators_ibfk_2"
        ),
        sa.ForeignKeyConstraint(
            ["created_by_fk"], ["ab_user.id"], name="alert_validators_ibfk_3"
        ),
        sa.PrimaryKeyConstraint("id"),
    )

    # Migrate data
    session = db.Session(bind=bind)
    alerts = session.query(Alert).all()
    for a in alerts:
        if a.sql:
            ob = SQLObserver(sql=a.sql, database_id=a.database_id)
            a.sql_observer.append(ob)
            session.add(ob)
        if a.validator_type:
            val = Validator(
                validator_type=a.validator_type,
                config=a.validator_config,
                alert_id=a.id,
            )
            a.validators.append(val)
            session.add(val)
    session.commit()

    # sqlite does not support dropping columns
    if isinstance(bind.dialect, SQLiteDialect):
        op.add_column(
            "sql_observations",
            sa.Column(
                "observer_id",
                sa.Integer(),
                autoincrement=False,
                nullable=False,
                server_default="0",
            ),
        )
        op.drop_table("alerts")
        create_table(
            "alerts",
            sa.Column("id", sa.Integer(), nullable=False),
            sa.Column("label", sa.String(length=150), nullable=False),
            sa.Column("active", sa.Boolean(), nullable=True),
            sa.Column("crontab", sa.String(length=50), nullable=False),
            sa.Column("alert_type", sa.String(length=50), nullable=True),
            sa.Column("log_retention", sa.Integer(), nullable=False, default=90),
            sa.Column(
                "grace_period", sa.Integer(), nullable=False, default=60 * 60 * 24
            ),
            sa.Column("recipients", sa.Text(), nullable=True),
            sa.Column("slice_id", sa.Integer(), nullable=True),
            sa.Column("dashboard_id", sa.Integer(), nullable=True),
            sa.Column("last_eval_dttm", sa.DateTime(), nullable=True),
            sa.Column("last_state", sa.String(length=10), nullable=True),
            sa.Column("changed_by_fk", sa.Integer(), nullable=True),
            sa.Column("changed_on", sa.DateTime(), nullable=True),
            sa.Column("created_by_fk", sa.Integer(), nullable=True),
            sa.Column("created_on", sa.DateTime(), nullable=True),
            sa.Column("slack_channel", sa.Text(), nullable=True),
            sa.ForeignKeyConstraint(
                ["dashboard_id"],
                ["dashboards.id"],
            ),
            sa.ForeignKeyConstraint(
                ["slice_id"],
                ["slices.id"],
            ),
            sa.ForeignKeyConstraint(
                ["created_by_fk"],
                ["ab_user.id"],
            ),
            sa.ForeignKeyConstraint(
                ["changed_by_fk"],
                ["ab_user.id"],
            ),
            sa.PrimaryKeyConstraint("id"),
        )
    else:
        op.add_column(
            "sql_observations",
            sa.Column(
                "observer_id",
                sa.Integer(),
                autoincrement=False,
                nullable=False,
                default=0,
            ),
        )
        constraint = generic_find_fk_constraint_name("alerts", {"id"}, "dbs", insp)
        op.drop_constraint(constraint, "alerts", type_="foreignkey")
        op.drop_column("alerts", "validator_type")
        op.drop_column("alerts", "sql")
        op.drop_column("alerts", "database_id")
        op.drop_column("alerts", "validator_config")

        op.create_foreign_key(
            "sql_observations_ibfk_2",
            "sql_observations",
            "sql_observers",
            ["observer_id"],
            ["id"],
        )