Migrations for adding issue_id to versions table

These migrations do the following:

- Adds a new `issue_id` column to `versions`. This fixes an n+1 problem
  when loading versions for an issue in GraphQL as AR can now load from
  cache
- Change the unique restraint on versions.sha to be scoped to `issue_id`
  as in order to import version data, we need to allow duplicate `sha`
  values for versions
- Update all versions with an `issue_id`

https://gitlab.com/gitlab-org/gitlab-ee/issues/11090

1 files changed, 19 insertions, 0 deletions

diff --git a/db/migrate/20190715043954_set_issue_id_for_all_versions.rb b/db/migrate/20190715043954_set_issue_id_for_all_versions.rb
new file mode 100644
index 00000000000..345b749f1a4
--- /dev/null
+++ b/db/migrate/20190715043954_set_issue_id_for_all_versions.rb
@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+class SetIssueIdForAllVersions < ActiveRecord::Migration[5.2]
+  DOWNTIME = false
+
+  def up
+    execute('UPDATE design_management_versions as versions SET issue_id = (
+      SELECT design_management_designs.issue_id
+        FROM design_management_designs
+        INNER JOIN design_management_designs_versions ON design_management_designs.id = design_management_designs_versions.design_id
+        WHERE design_management_designs_versions.version_id = versions.id
+        LIMIT 1
+    )')
+  end
+
+  def down
+    # no-op
+  end
+end