mysql，node.js

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

function MySQLHelper() {
};
function QuerySQL(querysql, callback) {
    pool.getConnection(function (err, conn) {
        //if (err) console.log("POOL ==> " + err);
        if (err) {
            conn.release();
            return callback(err);
        }
        conn.query(querysql, function (err2, rows) {
            //if (err) console.log(err);
            if (err2) {
                conn.release();
                return callback(err2);
            }
            //console.log("SELECT ==> ");
            conn.release();
            callback(err2,rows);
        });
    });
};

function ExecuteSQL(executesql, callback) {
    pool.getConnection(function (err, conn) {
        //if (err) console.log("POOL ==> " + err);
        if (err) {
            conn.release();
            return callback(err);
        }
        conn.query(executesql, function (err2, res) {
            //if (err) console.log(err);
            if (err2) {
                conn.release();
                return callback(err2);
            }
            //console.log("SELECT ==> ");
            conn.release();
            callback(err2,res.affectedRows);
        });
    });
};

MySQLHelper.prototype.ExecuteSQL = ExecuteSQL;
MySQLHelper.prototype.QuerySQL = QuerySQL;
module.exports = MySQLHelper;