Reject blank order_values within #columns_for_distinct, as the orders aren't used at all on non-postgres adapters.

1 files changed, 1 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
index 8feee23df0..a651b6c32e 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
@@ -470,7 +470,7 @@ module ActiveRecord
         # PostgreSQL requires the ORDER BY columns in the select list for distinct queries, and
         # requires that the ORDER BY include the distinct column.
         def columns_for_distinct(columns, orders) #:nodoc:
-          order_columns = orders.map{ |s|
+          order_columns = orders.reject(&:blank?).map{ |s|
               # Convert Arel node to string
               s = s.to_sql unless s.is_a?(String)
               # Remove any ASC/DESC modifiers