add error message

Author: mikesamuel

lib/SqlString.js

@@ -34,7 +34,9 @@ SqlString.escapeId = function escapeId(val, forbidQualified) {
     if (QUALIFIED_ID_REGEXP.test(sqlString)) {
       return sqlString;
     } else {
-      throw new TypeError();
+      throw new TypeError(
+        'raw sql reached ?? or escapeId but is not an identifier: ' +
+        sqlString);
     }
   } else if (forbidQualified) {
     return '`' + String(val).replace(ID_GLOBAL_REGEXP, '``') + '`';