Merge lp:~stevenk/launchpad/db-previewdiff-to-bmp into lp:launchpad/db-devel

[Steve Kowalik]

Add two new columns to PreviewDiff -- branch_merge_proposal and date_created.

Add two new columns to PreviewDiff -- branch_merge_proposal and date_created, which will duplicate (and later, replace) the foreign key that currently points from BranchMergeProposal -> PreviewDiff, and allows us to have more than one PreviewDiff per merge proposal.

[Stuart Bishop (stub)]

As mentioned on IRC, you will want an index on branch_merge_proposal or (branch_merge_proposal, date_created DESC)

review: Approve (db)

=== added file 'database/schema/patch-2209-44-0.sql'
--- database/schema/patch-2209-44-0.sql	1970-01-01 00:00:00 +0000
+++ database/schema/patch-2209-44-0.sql	2013-05-08 05:52:34 +0000
@@ -0,0 +1,13 @@
+-- Copyright 2013 Canonical Ltd.  This software is licensed under the
+-- GNU Affero General Public License version 3 (see the file LICENSE).
+
+SET client_min_messages=ERROR;
+
+ALTER TABLE previewdiff
+    ADD COLUMN branch_merge_proposal integer REFERENCES branchmergeproposal,
+    ADD COLUMN date_created timestamp without time zone;
+ALTER TABLE previewdiff
+    ALTER COLUMN date_created
+        SET DEFAULT (CURRENT_TIMESTAMP AT TIME ZONE 'UTC');
+
+INSERT INTO LaunchpadDatabaseRevision VALUES (2209, 44, 0);