WIP: Different solution for MySQL.32283-trending-projects-unique-constraint

1 files changed, 16 insertions, 10 deletions

diff --git a/db/migrate/20180131101039_remove_duplicates_in_trending_projects.rb b/db/migrate/20180131101039_remove_duplicates_in_trending_projects.rb
index b68f3a8167f..a0dc77d4a75 100644
--- a/db/migrate/20180131101039_remove_duplicates_in_trending_projects.rb
+++ b/db/migrate/20180131101039_remove_duplicates_in_trending_projects.rb
@@ -4,16 +4,22 @@ class RemoveDuplicatesInTrendingProjects < ActiveRecord::Migration
   DOWNTIME = false
 
   def up
-    connection.execute <<-SQL
-      DELETE FROM trending_projects WHERE id IN (
-        SELECT id FROM (
-          SELECT
-            id,
-            ROW_NUMBER() OVER (PARTITION BY project_id) AS row_number
-          FROM trending_projects
-        ) t WHERE t.row_number > 1
-      )
-    SQL
+    if Gitlab::Database.postgresql?
+      execute <<~SQL
+        DELETE FROM trending_projects WHERE id IN (
+          SELECT id FROM (
+            SELECT
+              id,
+              ROW_NUMBER() OVER (PARTITION BY project_id) AS row_number
+            FROM trending_projects
+          ) t WHERE t.row_number > 1
+        )
+      SQL
+    else
+      # No window functions in Mysql 5.x
+      # We can't modify a table we are selecting from on MySQL
+      fail 'TODO'
+    end
   end
 
   def down