查询条件为空时 不发起请求

src/views/system/device/index.vue

@@ -584,7 +584,8 @@ export default {
       this.changeSelect(data);
       this.handleQuery();
     },
-    changeSelect(val) {
+    changeSelect(val) {      
+      if(!val || !val.id) return;
       getHostByOrgId(val).then((response) => {
         this.form.hostId = null;
         this.hostList = response.data;