1 files changed, 25 insertions, 0 deletions
diff --git a/db/post_migrate/20170508170547_add_head_pipeline_for_each_merge_request.rb b/db/post_migrate/20170508170547_add_head_pipeline_for_each_merge_request.rb
new file mode 100644
index 00000000000..bc3850c0c23
--- /dev/null
+++ b/db/post_migrate/20170508170547_add_head_pipeline_for_each_merge_request.rb
@@ -0,0 +1,25 @@
+class AddHeadPipelineForEachMergeRequest < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  def up
+    disable_statement_timeout
+
+    pipelines = Arel::Table.new(:ci_pipelines)
+    merge_requests = Arel::Table.new(:merge_requests)
+
+    head_id = pipelines.
+      project(Arel::Nodes::NamedFunction.new('max', [pipelines[:id]])).
+      from(pipelines).
+      where(pipelines[:ref].eq(merge_requests[:source_branch])).
+      where(pipelines[:project_id].eq(merge_requests[:source_project_id]))
+
+    sub_query = Arel::Nodes::SqlLiteral.new(Arel::Nodes::Grouping.new(head_id).to_sql)
+
+    update_column_in_batches(:merge_requests, :head_pipeline_id, sub_query)
+  end
+
+  def down
+  end
+end