Synnefo » Pithos

"""alter nodes add column latest version

Revision ID: 230f8ce9c90f

Revises: 8320b1c62d9

Create Date: 2012-07-17 20:32:54.466145

"""

# revision identifiers, used by Alembic.

revision = '230f8ce9c90f'

down_revision = '8320b1c62d9'

from alembic import op, context

from sqlalchemy.sql import table, column

from alembic import op

import sqlalchemy as sa

def upgrade():

    op.add_column('nodes', sa.Column('latest_version', sa.INTEGER))

    n = table('nodes', 

        column('node', sa.Integer),

        column('latest_version', sa.Integer)

    )

    v = table('versions', 

        column('node', sa.Integer),

        column('mtime', sa.Integer),

        column('serial', sa.Integer),

    )

    s = sa.select([v.c.serial]).where(n.c.node == v.c.node).order_by(v.c.mtime).limit(1)

    op.execute(

        n.update().\

            values({'latest_version':s})

            )

def downgrade():

    op.drop_column('nodes', 'latest_version')