Improve performance of finding last deployed environment

1 files changed, 14 insertions, 0 deletions

diff --git a/lib/gitlab/database.rb b/lib/gitlab/database.rb
index 55b8f888d53..dc2537d36aa 100644
--- a/lib/gitlab/database.rb
+++ b/lib/gitlab/database.rb
@@ -35,6 +35,20 @@ module Gitlab
       order
     end
 
+    def self.nulls_first_order(field, direction = 'ASC')
+      order = "#{field} #{direction}"
+
+      if Gitlab::Database.postgresql?
+        order << ' NULLS FIRST'
+      else
+        # `field IS NULL` will be `0` for non-NULL columns and `1` for NULL
+        # columns. In the (default) ascending order, `0` comes first.
+        order.prepend("#{field} IS NULL, ") if direction == 'DESC'
+      end
+
+      order
+    end
+
     def self.random
       Gitlab::Database.postgresql? ? "RANDOM()" : "RAND()"
     end