Nodejs+mysql傳回查詢的資料結果

const mysqlDAO = require('./mysql.js');

//result為查詢傳回的結果
function processData(result) {
    var data = JSON.stringify(result)
    console.log("JSON:" + data);

    var json = JSON.parse(data);
    //自定義使用者内容
}

function dbTrainInfo() {
    var sql = `select * from stationtrain limit 2 `;
    //processData為回調方法
    mysqlDAO.queryDataBySQL(sql, processData);
}
           

mysql.js

var mysql = require("mysql");

var pool = mysql.createPool({
    host: 'localhost',
    user: 'root',
    password: '******',
    database: 'station',
    port: 3306
});

//callback為回調方法
function queryDataBySQL(sql, callback) {
    pool.getConnection(function (err, connection) {
        connection.query(sql, function (err, result) {
            if (err) {
                console.log(err);
            } else {
                //console.log("query:" + result);
                callback(result);
            }
        });
        connection.release();
        //console.log("close mysql connection");
    });
};

module.exports = {
    queryDataBySQL: queryDataBySQL
}