lib/thinking_sphinx/adapters/mysql_adapter.rb in thinking-sphinx-099-1.2.12 vs lib/thinking_sphinx/adapters/mysql_adapter.rb in thinking-sphinx-099-1.2.13

@@ -11,10 +11,10 @@
     def concatenate(clause, separator = ' ')
       "CONCAT_WS('#{separator}', #{clause})"
     end
     
     def group_concatenate(clause, separator = ' ')
-      "GROUP_CONCAT(DISTINCT #{clause} SEPARATOR '#{separator}')"
+      "GROUP_CONCAT(DISTINCT IFNULL(#{clause}, '0') SEPARATOR '#{separator}')"
     end
     
     def cast_to_string(clause)
       "CAST(#{clause} AS CHAR)"
     end
\ No newline at end of file