add column to packages for current_serial, as well as trigger on journal...

warehouse/migrations/versions/55b028ee498d_add_current_serial_and_trigger_for_.py

@@ -0,0 +1,68 @@
+# Copyright 2013 Donald Stufft
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""
+add current_serial and trigger for package journal
+
+Revision ID: 55b028ee498d
+Revises: 55eda9672691
+Create Date: 2014-02-09 11:52:39.756097
+"""
+from __future__ import absolute_import, division, print_function
+
+# revision identifiers, used by Alembic.
+revision = '55b028ee498d'
+down_revision = '55eda9672691'
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+def upgrade():
+    op.add_column(
+        "packages",
+        sa.Column("current_serial", sa.INTEGER, nullable=True),
+    )
+    op.execute("""
+        CREATE OR REPLACE FUNCTION update_packages_current_serial() RETURNS TRIGGER
+        AS $journals$
+            BEGIN
+                UPDATE packages
+                SET    current_serial = (SELECT MAX(id) FROM journals WHERE name = NEW.name);
+                RETURN NULL;
+            END;
+        $journals$
+        LANGUAGE 'plpgsql';
+    """)
+    op.execute("""
+        CREATE TRIGGER update_packages_current_serial
+        AFTER UPDATE OR INSERT ON journals
+        FOR EACH ROW
+        EXECUTE PROCEDURE update_packages_current_serial();
+    """)
+    op.execute("""
+        UPDATE packages
+        SET current_serial = (SELECT MAX(id) FROM journals WHERE name = packages.name)
+        WHERE current_serial IS NULL;
+    """)
+
+def downgrade():
+   op.execute("""
+       DROP TRIGGER update_packages_current_serial ON journals;
+   """)
+   op.execute("""
+       DROP FUNCTION update_packages_current_serial();
+   """)
+   op.drop_column(
+       "packages", "current_serial"
+   )