node.js实现js连接mysql数据库

一、安装包

在对应的目录打开cmd

npm i mysql

二、代码&接口

var _mysql = require('mysql');
var HOST = 'localhost';
var PORT = 3306;
var MYSQL_USER = 'root';
var MYSQL_PASS = '123456';
var DATABASE = 'js_login';
var mysql = _mysql.createConnection({
    host: HOST,
    port: PORT,
    user: MYSQL_USER,
    password: MYSQL_PASS,
});
var user = [];
mysql.query('use ' + DATABASE, function(error, results) {
    if(error) {
        console.log('ClientConnectionReady Error: ' + error.message);
        mysql.end();
        return;
    }
});
//查
GetData = function(client)
{
    client.query(
        'select * from user order by score DESC',
        function selectCb(error, results, fields) {
            if (error) {
                console.log('GetData Error: ' + error.message);
                client.end();
                return;
            }
            for(var i = 0; i < Math.max(10, results.length); i ++) {
                user[i] = results[i];
            }
        });
};
//改
Update = function(client,userid,score)
{
    var userModSql = 'UPDATE user SET score = ? WHERE userid = ?';
    var userModSql_Params = [score,userid];
    client.query(userModSql,userModSql_Params,function (err, result) {
        if(err){
            console.log('[UPDATE ERROR] - ',err.message);
            return;
        }
    });
    for(var i in user) {
        if(user[i].userid == userid) {
            user[i].score = score;
            break;
        }
    }
};
//删
Delete = function(client,userid)
{
    var userModSql = 'UPDATE user SET score = ? WHERE userid = ?';
    var userModSql_Params = [0,userid];
    client.query(userModSql,userModSql_Params,function (err, result) {
        if(err){
            console.log('[DELETE ERROR] - ',err.message);
            return;
        }
    });
    for(var i in user) {
        if(user[i].userid == userid) {
            user[i].score = 0;
            break;
        }
    }
};
//增
Insert = function(client,userid,pwd)
{
    var userModSql = 'INSERT INTO user(userid,pwd,score) value(?,?,?)';
    var userModSql_Params = [userid,pwd,0];
    client.query(userModSql,userModSql_Params,function (err, result) {
        if(err){
            console.log('[DELETE ERROR] - ',err.message);
            return;
        }
    });
    user.add({userid:userid,pwd:pwd,score:0});
};

GetData(mysql);