Merge pull request #7 from Kwal/master

Fix for multiple results from subquery

lib/mysql.js

@@ -19,6 +19,7 @@ var MySQL = function(credentials){
       select column_name from                       \
       information_schema.key_column_usage           \
       where table_name = ist.table_name             \
+      and constraint_schema = ist.table_schema      \
       and constraint_name = 'PRIMARY'               \
     )  as 'pk'                                      \
     from information_schema.tables ist              \