nodejs连接mysql之使用连接池pool

//导入所需模块
var mysql=require("mysql");
//导入配置文件
var cfg  =require("./config/db");
var pool = mysql.createPool({
host:      cfg.HOST,
user:      cfg.USER,
password:  cfg.PASS,
database:  cfg.NAME
port:      cfg.PORT
});
//导出查询相关
var query=function(sql,callback){
pool.getConnection(function(err,conn){
if(err){
callback(err,null,null);
}else{
conn.query(sql,function(qerr,vals,fields){
//释放连接
conn.release();
//事件驱动回调
callback(qerr,vals,fields);
});
}
});
};

module.exports=query;

var query=require("./lib/pool.js");

query("select * from token ",function(err,vals,fields){
//其他信息
});