node mysql 请求数据库返回值 报错write after end

Question

问题描述

node接受请求查询数据库，查询带有值，返回时候出错 报错write after end

相关代码

//    console.log(startTime,id,endTime)
var express = require('express');
var app = express();

var mysql = require('mysql');
var connection = mysql.createConnection({
    host: '127.0.0.1', // 接口
    user: 'root', // 用户名
    port : '3306',
    password: '', //密码
    database: "lbst" // 表

});

connection.connect();
if(startTime != null) {
    //         var sql='select from lb_admin_addon where starTime= '+startTime+' and id='+ id +' and endTime='+endTime;
    //    select * from market_orders where createdate>='2010-03-01 00:00:00' and createdate<'2016-03-02 00:00:00'
    //         
    var sql = `
           SELECT * FROM lb_addmin_taglist WHERE timestamp>='${startTime}'  AND timestamp<'${endTime}'
       `
} else {
    var sql = 'select * from lb_admin_msg';
}
var sqlarr = [];
connection.query(sql, function selectCB(err, results, fields) {
    if(err) {
        throw err;
    }
    if(results) {
        for(var a = 0; a < results.length; a++) {
            sqlarr.push(results[a])
        }
    }
    connection.end();
})

function ztstInterval() {
    clearInterval(searchArr)
}
var num = 0;
var searchArr = setInterval(function() {
    num++;
    console.log(sqlarr.length)
    if(sqlarr.length != 0) {
        ztstInterval();
        sqlarr = JSON.stringify(sqlarr)
        //               response.writeHead(200, {'Content-Type': 'text/plain; charset=utf-8'});
        var msg = {
            "数据": 200,
            data: sqlarr
        }
        response.write(1);
        response.end(msg);
    }
}, 1000)