ExtJS中store.findExact

  var ds = myGrid.apf_ds;
  var store = myGrid.getStore();

 forEach(data, function (item) {
     if (store.findExact("code", item["code"]) < 0) {

             var record = ds.addRecord();
             record.set("code", item.code);
             ...
         }
     }
 });