Migration script to add template version to jobs and notifications.

migrations/versions/0013_add_template_version.py

@@ -0,0 +1,29 @@
+"""empty message
+
+Revision ID: 0013_add_template_version
+Revises: 0010_events_table
+Create Date: 2016-05-11 16:00:51.478012
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '0013_add_template_version'
+down_revision = '0010_events_table'
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+def upgrade():
+    op.add_column('jobs', sa.Column('template_version', sa.Integer(), nullable=True))
+    op.get_bind()
+    op.execute('update jobs set template_version = (select version from templates where id = template_id)')
+    op.add_column('notifications', sa.Column('template_version', sa.Integer(), nullable=True))
+    op.execute('update notifications set template_version = (select version from templates where id = template_id)')
+    op.alter_column('jobs', 'template_version', nullable=False)
+    op.alter_column('notifications', 'template_version', nullable=False)
+
+
+def downgrade():
+    op.drop_column('notifications', 'template_version')
+    op.drop_column('jobs', 'template_version')