Node+Express连接mysql实现增删改查

文章目录

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一、在项目中安装mysql 和 express

二、示例代码：

const express = require("express"); 
const app = express(); 
const mysql = require("mysql"); 
 

// 创建连接

const db = mysql.createConnection({ 
    host:"localhost", 
    user:"root", 
    password:"root", 
    database:"nodemysql" 
}) 
db.connect( (err) => { 
    if(err) throw err; 
    console.log('连接成功'); 
}) 

// 创建数据库

app.get("/createdb",(req,res) => { 
    let sql = "CREATE DATABASE nodemysql"; 
    db.query(sql,(err,result) => { 
        if(err){ 
            console.log(err); 
        }else{ 
            console.log(result); 
            res.send("Datebase create success...") 
        } 
    }) 
}) 

// 创建表

app.get("/createpoststable",(req,res) => { 
    //  创建表 表名为posts id自增 title字符串长度255 body字符串255 主键是ID 
    let sql = "CREATE TABLE posts(id int AUTO_INCREMENT,title VARCHAR(255),body VARCHAR(255),PRIMARY KEY(ID))"; 
    db.query(sql,(err,result) => { 
        if(err){ 
            console.log(err); 
        }else{ 
            console.log(result); 
            res.send("posts表创建成功....") 
        } 
    }) 
}) 

// 插入数据

app.get("/addpost2",(req,res) => { 
    let post = {title:"post two",body:"weasth"}; 
    let sql = "INSERT INTO posts SET ?"; 
    db.query(sql,post,(err,result) => { 
        if(err){ 
            console.log(err); 
        }else{ 
            console.log(result); 
            res.send("post2 added....") 
        } 
    }) 
}) 

// 查询内容

app.get("/getposts",(req,res) => { 
    let sql = "SELECT * FROM posts"; 
    db.query(sql,(err,result) => { 
        if(err){ 
            console.log(err); 
        }else{ 
            console.log(result); 
            // res.send("查询成功") 
            res.json(result) 
        } 
    }) 
}) 

// 查询单条内容

app.get("/getposts/:id",(req,res) => { 
    let sql = `SELECT * FROM posts WHERE id = ${req.params.id}`; 
    db.query(sql,(err,result) => { 
        if(err){ 
            console.log(err); 
        }else{ 
            console.log(result); 
            res.json(result) 
        } 
    }) 
}) 

// 更新内容

app.get("/updatepost/:id",(req,res) => { 
    let newTitle = "update title"; 
    let sql = `UPDATE posts SET title = '${newTitle}' WHERE id = ${req.params.id}`; 
    db.query(sql,(err,result) => { 
        if(err){ 
            console.log(err); 
        }else{ 
            console.log(result); 
            res.send(`update ${req.params.id} success....`) 
        } 
    }) 
}) 

// 删除内容

app.get("/deletepost/:id",(req,res) => { 
    let sql = `DELETE FROM posts WHERE id = ${req.params.id}`; 
    db.query(sql,(err,result) => { 
        if(err){ 
            console.log(err); 
        }else{ 
            console.log(result); 
            res.send("删除成功.....") 
        } 
    }) 
}) 
 

app.listen(3000, () => { 
    console.log("服务器开启在3000端口...."); 
})