Convert enabled for Client, Probe to use datetime instead of boolean

value is null if disabled, else timestamp of when it was last enabled

rattail_tempmon/db/alembic/versions/fd1df160539a_make_enabled_datetime.py

@@ -0,0 +1,80 @@
+# -*- coding: utf-8; -*-
+"""make enabled datetime
+
+Revision ID: fd1df160539a
+Revises: a2676d3dfc1e
+Create Date: 2019-01-25 18:41:01.652823
+
+"""
+
+from __future__ import unicode_literals, absolute_import
+
+# revision identifiers, used by Alembic.
+revision = 'fd1df160539a'
+down_revision = 'a2676d3dfc1e'
+branch_labels = None
+depends_on = None
+
+import datetime
+from alembic import op
+import sqlalchemy as sa
+import rattail.db.types
+
+
+
+def upgrade():
+
+    now = datetime.datetime.utcnow()
+
+    # client
+    op.add_column('client', sa.Column('new_enabled', sa.DateTime(), nullable=True))
+    client = sa.sql.table('client',
+                          sa.sql.column('enabled'),
+                          sa.sql.column('new_enabled'))
+    op.execute(client.update()\
+               .where(client.c.enabled == True)\
+               .values({'new_enabled': now}))
+    op.drop_column('client', 'enabled')
+    op.alter_column('client', 'new_enabled', new_column_name='enabled')
+
+    # probe
+    op.add_column('probe', sa.Column('new_enabled', sa.DateTime(), nullable=True))
+    probe = sa.sql.table('probe',
+                         sa.sql.column('enabled'),
+                         sa.sql.column('new_enabled'))
+    op.execute(probe.update()\
+               .where(probe.c.enabled == True)\
+               .values({'new_enabled': now}))
+    op.drop_column('probe', 'enabled')
+    op.alter_column('probe', 'new_enabled', new_column_name='enabled')
+
+
+def downgrade():
+
+    # probe
+    op.add_column('probe', sa.Column('old_enabled', sa.Boolean(), nullable=True))
+    probe = sa.sql.table('probe',
+                         sa.sql.column('enabled'),
+                         sa.sql.column('old_enabled'))
+    op.execute(probe.update()\
+               .where(probe.c.enabled != None)\
+               .values({'old_enabled': True}))
+    op.execute(probe.update()\
+               .where(probe.c.enabled == None)\
+               .values({'old_enabled': False}))
+    op.drop_column('probe', 'enabled')
+    op.alter_column('probe', 'old_enabled', new_column_name='enabled', nullable=False)
+
+    # client
+    op.add_column('client', sa.Column('old_enabled', sa.Boolean(), nullable=True))
+    client = sa.sql.table('client',
+                          sa.sql.column('enabled'),
+                          sa.sql.column('old_enabled'))
+    op.execute(client.update()\
+               .where(client.c.enabled != None)\
+               .values({'old_enabled': True}))
+    op.execute(client.update()\
+               .where(client.c.enabled == None)\
+               .values({'old_enabled': False}))
+    op.drop_column('client', 'enabled')
+    op.alter_column('client', 'old_enabled', new_column_name='enabled', nullable=False)