node mysql的增删改查基础

学习koa时，不选择mongodb，而是MySQL，虽然node对mongodb更亲和，但是我感觉MySQL的键值对的储存结构更正规

1.首选确认你的数据库有个库。有个表,我的如下

2.配置

let mySqlConfig={
    host:'localhost',
    user:'root',
    password:'123456',
    database:'X',
    port:'3306'
}
module.exports=mySqlConfig

const mysql=require('mysql');
const mysqlConfig=require('../config/');//上面的mySqlConfig代码
var connection = mysql.createConnection(mysqlConfig);
connection.connect();

1.查

const c = 'SELECT * FROM user';
connection.query(c,function (err, result) {
    if(err){
     console.log('[SELECT ERROR] - ',err.message);
     return;
    }
    console.log('---------------SELECT----------------');
    console.log(result);
    console.log('-------------------------------------');
});

结果

2.改

const userModSql = 'UPDATE user SET name = ?,sex = ? ,age= ? where id= ?';
const userModSql_Params = ["王五","女","22","3"];
connection.query(userModSql,userModSql_Params,function (err, result) {
    if(err){
       console.log('[UPDATE ERROR] - ',err.message);
       return;
    }
   console.log('----------UPDATE-------------');
   console.log('UPDATE affectedRows',result.affectedRows);
   console.log('******************************');
  });

结果

3.删

const userDelSql = 'DELETE FROM user WHERE id = 3';
connection.query(userDelSql,function (err, result) {
    if(err){
     console.log('[DELETE ERROR] - ',err.message);
     return;
    }
    console.log('-------------DELETE--------------');
    console.log('DELETE affectedRows',result.affectedRows);
    console.log('*********************************');
});

结果

4.增

const  sql = 'INSERT INTO user(name,sex,age) VALUES(?,?,?)';
const  params = ['张四', '男','21'];
connection.query(sql, params, function (err, result) {
    if(err){
        console.log('[UPDATE ERROR] - ',err.message);
        return;
     }
    console.log('----------UPDATE-------------');
    console.log('UPDATE affectedRows',result.affectedRows);
    console.log('******************************');
});

结果

完整一套

const mysql=require('mysql');
const mysqlConfig=require('../config/');
var connection = mysql.createConnection(mysqlConfig);
connection.connect();

//查 query
const c = 'SELECT * FROM user';
connection.query(c,function (err, result) {
    if(err){
     console.log('[SELECT ERROR] - ',err.message);
     return;
    }
    console.log('---------------SELECT----------------');
    console.log(result);
    console.log('-------------------------------------');
});

// 增 insert
const  sql = 'INSERT INTO user(name,sex,age) VALUES(?,?,?)';
const  params = ['张四', '男','21'];
connection.query(sql, params, function (err, result) {
    if(err){
        console.log('[UPDATE ERROR] - ',err.message);
        return;
     }
    console.log('----------UPDATE-------------');
    console.log('UPDATE affectedRows',result.affectedRows);
    console.log('******************************');
});

// //改 update
const userModSql = 'UPDATE user SET name = ?,sex = ? ,age= ? where id= ?';
const userModSql_Params = ["王五","女","22","3"];
connection.query(userModSql,userModSql_Params,function (err, result) {
    if(err){
       console.log('[UPDATE ERROR] - ',err.message);
       return;
    }
   console.log('----------UPDATE-------------');
   console.log('UPDATE affectedRows',result.affectedRows);
   console.log('******************************');
  });

//删 delete
const userDelSql = 'DELETE FROM user WHERE id = 3';
connection.query(userDelSql,function (err, result) {
    if(err){
     console.log('[DELETE ERROR] - ',err.message);
     return;
    }
    console.log('-------------DELETE--------------');
    console.log('DELETE affectedRows',result.affectedRows);
    console.log('&&&&&&&&&&&&&&&&&');
});
connection.end();

查询语句不会的就直接看看MySQL