//参数
var us = {
    mysql: require('mysql'),
    sqle: {}
};

//连接数据库
us.mysqlconnection = function (host, database) {
    if (!us.sqle[host] || !us.sqle[host][database]) { //配置数据库连接 
        us.sqle[host] = us.sqle[host] || {};
        us.sqle[host][database] = us.mysql.createPool({
            connectionLimit: 0,
            acquireTimeout: 60000,
            host: host, //数据库地址
            user: "root", //用户名
            password: "cocorobo", //密码
            database: database, //数据库名称
            port: 3306 //端口
        }); //连接超时和错误从连
    }
    //connectionLimit: 1000, 
    return us.sqle[host][database]; //返回连接对象
}


//连接数据库调用
exports.usselect = function (param, callback) {
    if (param.length > 1) {
        var _mysqlconnection = us.mysqlconnection(param[0], param[1]); //创建连接池
        console.log(param);
        _mysqlconnection.getConnection(function (error, connection) { //获取连接
            if (error) { //连接错误
                console.error("连接失败：", error);
            } else { //连接成功
                var _sql = "CALL ";
                var _param = new Array();
                if (param.length > 3) { //带有参数的sql语句  如：'call test(?, ?, ?);'
                    _param = param.slice(3) //截取有效参数
                    _sql += (param[2] || "") + "(?"; //拼接存储过程名称
                    _sql += Array(_param.length).join(",?");
                    _sql += ");"; //拼接结果语句
                } else { //不带参数的sql语句 如：'call test();'
                    _sql += param[2] + "();";
                }
                console.log("拼凑的MySQl语句为：", _sql);
                connection.query(_sql, _param, function (error, results, fields) { //执行sql语句 
                    if (results) {
                        callback(results.affectedRows != null ? results.affectedRows : results.length > 1 ? results : results[0]);
                    }
                    else { //执行错误
                        console.error("sql执行失败", error || "");
                        callback(error);
                    }
                });

                connection.release(function (error) { //释放资源
                    if (error) console.log("连接释放错误", error);
                });

            }
        });
    }
}


//重新连接处理
// us.mysqlconnet.reconnection = function (host, database, error) {
//     if (error) {
//         console.log("连接失败,尝试重连", error);
//         setTimeout(function () {
//             us.mysqlconnection(host, database)
//         }, 2000);
//     }
// }