新建一個文件夾node.js,目錄下打開命令初始化一下
cnpm init
然后下載express框架
cnpm install express --save
接着下載數據庫的依賴
cnpm install mysql --save
最后在目錄下建立一個db.js
var express=require('express');
var app =express();
var mysql = require('mysql');
//鏈接數據庫
var connection = mysql.createConnection({
host: '數據庫地址',
user: '數據庫賬號',
password : '數據庫密碼',
database : '數據庫名'
});
connection.connect();
//設置跨域訪問
app.all('*', function(req, res, next) {
res.header("Access-Control-Allow-Origin", "*");
res.header("Access-Control-Allow-Headers", "X-Requested-With");
res.header("Access-Control-Allow-Methods","PUT,POST,GET,DELETE,OPTIONS");
res.header("X-Powered-By",' 3.2.1');
res.header("Content-Type", "application/json;charset=utf-8");
next();
});
var result = {
"status": "200",
"message": "success",
}
connection.query('select * from websites', function(err, rows, fields) {
if (err) throw err;
return result.data=rows;
});
connection.end();
//寫個接口123
app.get('/123',function(req,res){
res.status(200),
res.json(result)
});
//配置服務端口
var server = app.listen(3000, function () {
var host = server.address().address;
var port = server.address().port;
console.log('Example app listening at http://%s:%s', host, port);
})
前提是你要開啟你 本地的數據庫,不然是連接不到的,且,你要新建一個數據庫新建一個表,具體可以去mysql官網查看
再在目錄下新建一個index.html
<!DOCTYPE html>
<html>
<head>
<title>node</title>
</head>
<body>
<button onclick="get()">請求數據</button>
<script src="https://cdn.bootcss.com/jquery/3.3.1/jquery.min.js"></script>
<script>
function get(){
$.ajax({
type:'get',
url:'http://localhost:3000/123',
success:function(data){
console.log(data);
},
error:function(){
console.log('error');
}
})
}
</script>
</body>
</html>
最后cmd中執行node db.js
如下是我建立的本地的數據庫
