From 793b9a5ced5f97feabca329e335f8ce7b1fb6708 Mon Sep 17 00:00:00 2001
From: Valery Sizov <valery@gitlab.com>
Date: Tue, 16 May 2017 21:18:15 +0300
Subject: Improve migration for Multipple issue assignee feature

---
 ...516153305_migrate_assignee_to_separate_table.rb | 83 ++++++++++++++++++++++
 1 file changed, 83 insertions(+)
 create mode 100644 db/migrate/20170516153305_migrate_assignee_to_separate_table.rb

(limited to 'db/migrate/20170516153305_migrate_assignee_to_separate_table.rb')

diff --git a/db/migrate/20170516153305_migrate_assignee_to_separate_table.rb b/db/migrate/20170516153305_migrate_assignee_to_separate_table.rb
new file mode 100644
index 00000000000..f269ca7fc34
--- /dev/null
+++ b/db/migrate/20170516153305_migrate_assignee_to_separate_table.rb
@@ -0,0 +1,83 @@
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class MigrateAssigneeToSeparateTable < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  # Set this constant to true if this migration requires downtime.
+  DOWNTIME = false
+
+  # When a migration requires downtime you **must** uncomment the following
+  # constant and define a short and easy to understand explanation as to why the
+  # migration requires downtime.
+  # DOWNTIME_REASON = ''
+
+  # When using the methods "add_concurrent_index", "remove_concurrent_index" or
+  # "add_column_with_default" you must disable the use of transactions
+  # as these methods can not run in an existing transaction.
+  # When using "add_concurrent_index" or "remove_concurrent_index" methods make sure
+  # that either of them is the _only_ method called in the migration,
+  # any other changes should go in a separate migration.
+  # This ensures that upon failure _only_ the index creation or removing fails
+  # and can be retried or reverted easily.
+  #
+  # To disable transactions uncomment the following line and remove these
+  # comments:
+  # disable_ddl_transaction!
+
+  def up
+    drop_table(:issue_assignees) if table_exists?(:issue_assignees)
+
+    if Gitlab::Database.mysql?
+      execute <<-EOF
+        CREATE TABLE issue_assignees AS
+          SELECT assignee_id AS user_id, id AS issue_id FROM issues WHERE assignee_id IS NOT NULL
+      EOF
+    else
+      ActiveRecord::Base.transaction do
+        execute('LOCK TABLE issues IN EXCLUSIVE MODE')
+
+        execute <<-EOF
+          CREATE TABLE issue_assignees AS
+            SELECT assignee_id AS user_id, id AS issue_id FROM issues WHERE assignee_id IS NOT NULL
+        EOF
+
+        execute <<-EOF
+            CREATE OR REPLACE FUNCTION replicate_assignee_id()
+            RETURNS trigger AS
+            $BODY$
+            BEGIN
+              if OLD.assignee_id IS NOT NULL THEN
+                  DELETE FROM issue_assignees WHERE issue_id = OLD.id;
+              END IF;
+
+              if NEW.assignee_id IS NOT NULL THEN
+                  INSERT INTO issue_assignees (user_id, issue_id) VALUES (NEW.assignee_id, NEW.id);
+              END IF;
+
+              RETURN NEW;
+            END;
+            $BODY$
+            LANGUAGE 'plpgsql'
+            VOLATILE;
+
+            CREATE TRIGGER replicate_assignee_id
+            BEFORE INSERT OR UPDATE OF assignee_id
+            ON issues
+            FOR EACH ROW EXECUTE PROCEDURE replicate_assignee_id();
+        EOF
+      end
+    end
+  end
+
+  def down
+    drop_table(:issue_assignees) if table_exists?(:issue_assignees)
+
+    if Gitlab::Database.postgresql?
+      execute <<-EOF
+        DROP TRIGGER IF EXISTS replicate_assignee_id ON issues;
+        DROP FUNCTION IF EXISTS replicate_assignee_id();
+      EOF
+    end
+  end
+end
-- 
cgit v1.2.1


From cb4ee4b1314de77554db10645c5f2f5717088f63 Mon Sep 17 00:00:00 2001
From: Yorick Peterse <yorickpeterse@gmail.com>
Date: Wed, 17 May 2017 22:56:23 +0200
Subject: Check if OLD is set when migrating issue assignees

The procedure for migrating issue assignees is invoked on both an INSERT
and UPDATE. This means it will fail for INSERTs because OLD is set to
NULL in this case.
---
 db/migrate/20170516153305_migrate_assignee_to_separate_table.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'db/migrate/20170516153305_migrate_assignee_to_separate_table.rb')

diff --git a/db/migrate/20170516153305_migrate_assignee_to_separate_table.rb b/db/migrate/20170516153305_migrate_assignee_to_separate_table.rb
index f269ca7fc34..eed9f00d8b2 100644
--- a/db/migrate/20170516153305_migrate_assignee_to_separate_table.rb
+++ b/db/migrate/20170516153305_migrate_assignee_to_separate_table.rb
@@ -47,7 +47,7 @@ class MigrateAssigneeToSeparateTable < ActiveRecord::Migration
             RETURNS trigger AS
             $BODY$
             BEGIN
-              if OLD.assignee_id IS NOT NULL THEN
+              if OLD IS NOT NULL AND OLD.assignee_id IS NOT NULL THEN
                   DELETE FROM issue_assignees WHERE issue_id = OLD.id;
               END IF;
 
-- 
cgit v1.2.1