Make sure invalid fields are filtered out

lib/sql.js

@@ -914,8 +914,10 @@ SQLConnector.prototype.buildColumnNames = function(model, filter) {
   var self = this;
   var keys = Object.keys(cols);
   if (Array.isArray(fieldsFilter) && fieldsFilter.length > 0) {
-    // No empty array, including all the fields
-    keys = fieldsFilter;
+    // Not empty array, including all the fields that are valid properties
+    keys = fieldsFilter.filter(function(f) {
+      return cols[f];
+    });
   } else if ('object' === typeof fieldsFilter &&
     Object.keys(fieldsFilter).length > 0) {
     // { field1: boolean, field2: boolean ... }