"""Migrate negative weights Revision ID: a67119aa3ee5 Revises: afbf27e6ef20 Create Date: 2018-12-25 18:34:20.220844 """ # revision identifiers, used by Alembic. revision = "a67119aa3ee5" down_revision = "afbf27e6ef20" from alembic import op import sqlalchemy as sa # Snapshot of the person table person_helper = sa.Table( "person", sa.MetaData(), sa.Column("id", sa.Integer(), nullable=False), sa.Column("project_id", sa.String(length=64), nullable=True), sa.Column("name", sa.UnicodeText(), nullable=True), sa.Column("activated", sa.Boolean(), nullable=True), sa.Column("weight", sa.Float(), nullable=True), sa.ForeignKeyConstraint(["project_id"], ["project.id"]), sa.PrimaryKeyConstraint("id"), ) def upgrade(): op.execute( person_helper.update().where(person_helper.c.weight <= 0).values(weight=1) ) def downgrade(): # Downgrade path is not possible, because information has been lost. pass