"""Add the remote_git entry

Revision ID: 257a7ce22682

Revises: 36116bb7a69b

Create Date: 2015-07-21 14:26:23.989220

"""

# revision identifiers, used by Alembic.

revision = '257a7ce22682'

down_revision = '36116bb7a69b'

from alembic import op

import sqlalchemy as sa

def upgrade():

    ''' Add the column remote_git to the table pull_requests and make the

    project_id_from field nullable.

    '''

    op.add_column(

        'pull_requests',

        sa.Column('remote_git', sa.Text, nullable=True)

    )

    op.alter_column(

        'pull_requests',

        column_name='project_id_from',

        nullable=True,

        existing_nullable=False)

    op.create_check_constraint(

        "ck_lcl_or_remo_pr",

        "pull_requests",

        'NOT(project_id_from IS NULL AND remote_git IS NULL)'

    )

def downgrade():

    ''' Remove the column remote_git from the table pull_requests and make

    the project_id_from field not nullable.

    '''

    op.drop_column('pull_requests', 'remote_git')

    op.alter_column(

        'pull_requests',

        column_name='project_id_from',

        nullable=False,

        existing_nullable=True)