用js简单提供增删改查接口

// package.json
{
 "name": "test",
 "version": "1.0.0",
 "description": "",
 "main": "index.js",
 "scripts": {
 "test": "echo \"Error: no test specified\" && exit 1"
 },
 "author": "",
 "license": "ISC"
}

$ npm install express

var express = require('express');
var app = express();

app.get('/', function(req, res) {
 res.send('hello world!');
});
app.listen(3000, function() {
 console.log('server now listening at 3000 port');
});

$ node index.js
server now listening at 3000 port

$ npm install mysql
npm WARN test@1.0.0 No description
npm WARN test@1.0.0 No repository field.

+ mysql@2.17.1
added 9 packages from 14 contributors and audited 134 packages in 4.145s
found 0 vulnerabilities

//db.js
var mysql = require('mysql');
var pool = mysql.createPool({ //连接信息
 host: "localhost",
 user: "root",
 password: "",
 database: "c#learn",
 port: "3306"
});

var sql = { 
 insert:'INSERT INTO teacher(name, username, email, sex) VALUES("color: #ff0000">提供后台接口

在index.js导入db.js,并且将http请求和数据库操作对接:


var express = require('express');
var app = express();
var db = require('./db.js');

app.get('/', function(req, res) {
 res.header("Access-Control-Allow-Origin", "*");
 db.query(db.sql.queryAll, [], function(err, rows) {
  res.send(JSON.stringify(rows));
 });
});
这时再访问localhost:3000就能看我们teacher表中所有的记录了。
app.listen(3000, function() {
 console.log('server now listening at 3000 port');
});





另外,为了读取post和put里的body信息,我们需要body-parser这个包:


$ npm install body-parser


使用bodyParser来配置app:


//index.js
var express = require('express');
var db = require('./db.js');
var app = express();
var bodyParser = require('body-parser');

app.use(bodyParser.json());


这时就可以用req.body读取请求体了.


完整代码:


var express = require('express');
var db = require('./db.js');
var app = express();
var bodyParser = require('body-parser');

app.use(bodyParser.json());

app.get('/', function(req, res) {
 res.header("Access-Control-Allow-Origin", "*");
 db.query(db.sql.queryAll, [], function(err, rows) {
  console.log('err', err, 'rows', rows);
  res.send(JSON.stringify(rows));
 });
});

app.get('/:id', function(req, res) {
 res.header("Access-Control-Allow-Origin", "*");
 db.query(db.sql.queryById, [req.params.id], function(err, rows) {
  res.send(JSON.stringify(rows));
 });
});

app.post('', function(req, res) {
 res.header("Access-Control-Allow-Origin", "*");
 console.log(req.body.name);
 var teacher = req.body;
 db.query(db.sql.insert, [teacher.name, teacher.username, teacher.email, teacher.sex], function(err, rows) {
  if (err) {
   res.status(500);
   res.send('insert error');
  } else {
   res.status(200);
   res.send('insert success');
  }
 });
});

app.put('/:id', function(req, res) {
 res.header("Access-Control-Allow-Origin", "*");
 var teacher = req.body;
 var array = [teacher.name, teacher.username, teacher.email, teacher.sex, req.params.id];
 db.query(db.sql.update, array, function(err, rows) {
  if (err) {
   res.status(500);
   res.send('update error');
  } else {
   res.status(200);
   res.send('update success');
  }
 });
});

app.delete('/:id', function(req, res) {
 res.header("Access-Control-Allow-Origin", "*");
 db.query(db.sql.delete, [req.params.id], function(err, rows) {
  if (err) {
   res.status(500);
   res.send('delete error');
  } else {
   res.status(200);
   res.send('delete success');
  }
 });
});

app.listen(3000, function() {
 console.log('server now listening at 3000 port');
});



总结
感觉算是理解了语言只是工具这句话.
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。