在角度2 +

Question

我希望我的angular.ts文件中的所有函数继续重复执行以获取UI上的实时数据。所以我用了Observables。但是我遇到了一个SQL错误。

这里的问题是一个错误-

[1]

 mySQL Error - Too many connections . 

该错误的解决方法是什么。我包括了角度代码和节点代码

代码-

component.ts

    export class DashboardComponent {
    ngOnInit() {
    Observable.interval(5000).subscribe(x => {
    this.viewEntireData()
    });

     }


   viewEntireData() {

   console.log("INSIDE viewEntireData()")

   var url = config.url;
   var port = config.port;


      this.http.post("http://" + url + ":" + port + 
      "/dashboard/entireSuccess/", this.emptyObj
       , { headers: new Headers({ 'Authorization': 'Bearer ' + 
         localStorage.getItem('Token') }) })
      .map(resultSuccess1 => this.resultSuccess1 = 
        resultSuccess1.json(), )
      .subscribe((res: Response) => {



        this.entireSuccessResult = this.resultSuccess1.length;

      });

      });


        }

        }

NODEJS代码-

  function entireSuccess() {

   var sqlQuery = `select * from TRANSACTION_PAYLOAD where 
   INTERFACE_NAME = 'Experian' AND (STATUS ='SUCCESS_RESPONSE')`

var deferred = Q.defer();



    var host = config.host;
    var user = config.user;
    var password = config.password;
    var database = config.database;



   var con = mysql.createConnection({
    host: host,
    user: user,
    password: password,
    database: database
     });



   con.connect(function (err) {
    if (err) deferred.reject(err.name + ': ' + err.message);

    con.query(sqlQuery,
        function (err, result, fields) {
            if (err) deferred.reject(err.name + ': ' + err.message);
            // if (err) throw err;

            console.log(result);
            deferred.resolve(result);
        });
     });
    return deferred.promise; 
    con.close();
    con.close();


     }