nodeJs连接mysql有哪些方法

//连接数据库
var mysql = require('mysql');
var pool = mysql.createPool({
 host: 'localhost',
 user: 'root',
 password: 'gfdfsdf34r34r',
 database:'caiji'
});
module.exports = function(sql, callback) {
 pool.getConnection(function(conn_err, conn) {
 if(conn_err) {
 callback(err,null,null);
 } else {
 conn.query(sql, function(query_err, rows, fields) {
 conn.release();
 callback(query_err, rows, fields);
 });
 }
 });
};

var query = require("./mysql.js");
query(sql, function(err, rows, fields) {
 console.log(rows);
});