message: Drop constraint
diff: @@ -28,9 +28,30 @@ down_revision = "32646df09c64"
  import sqlalchemy as sa
  from alembic import op
  +from sqlalchemy.engine.reflection import Inspector
  def upgrade():
  + try:
  + with op.batch_alter_table("dbs") as batch_op:
  + batch_op.alter_column(
  + "allow_csv_upload",
  + new_column_name="allow_file_upload",
  + existing_type=sa.Boolean(),
  + )
  + except sa.exc.OperationalError:
  + # In MySQL 8.0 renaming the column rename fails because it has
  + # a constraint check; we can safely remove it in that case, see
  + # https://github.com/sqlalchemy/alembic/issues/699
  + bind = op.get_bind()
  + inspector = Inspector.from_engine(bind)
  + check_constraints = inspector.get_check_constraints("dbs")
  + for check_constraint in check_constraints:
  + if "allow_csv_upload" in check_constraint["sqltext"]:
  + name = check_constraint["name"]
  + op.drop_constraint(name, table_name="dbs", type_="check")
  +
  + # try again
  with op.batch_alter_table("dbs") as batch_op:
  batch_op.alter_column(
  "allow_csv_upload",
  