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nodejs 数据交互(增删改查)+Mysql+路由+bodyParser(中间件)+ejs模板

2019-01-30 09:49 309 查看

前提

  1. 安装好nodejs环境和Mysql
  2. 安装好bodyParser(中间件)+ejs模板
  3. 创建好数据库
    如图:
    创建一个工程目录

设计思路

一个功能对应一个页面,修改和删除为了方便把它们都放在一起了

代码块

app.js

var express = require('express');
var path = require('path');
var app = express();
var bodyParser = require('body-parser');
//body-parser只能解析单层对象
var select = require('./routes/select');
var all = require('./routes/selectall');
var add = require('./routes/add');
var updata = require('./routes/updata');
//模板引擎设置
app.set('views', path.join(__dirname, 'views'));
//app.set('view engine', 'jade');
app.engine("html",require("ejs").__express);
//设置视图模板引擎为html
app.set('view engine', 'html');

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({
extended: true
}));

//设置路由

app.use('/select',select);
app.use ('/all',all);
app.use('/add',add);
app.use('/updata',updata);
app.listen(3000);
console.log("启动端口:3000");

select.js

var express = require('express');
var router = express.Router();
var Data = require("./db.js");

router.get('/', function(req, res, next) {

res.render('select.html', {result:""});

});

router.post('/',function(req, res){
var selectdata = new Data();
// 对前端页面进行匹配,匹配到则输出
selectdata.select(function(err, result){

for (var i = 0 ; i< result.length; i++) {

var resultdata;
if (req.body.msg==result[i].name) {
resultdata = result[i];
break;
}
else
{
resultdata = "没找到相应数据";

}

}

res.render('select.html', {result:resultdata});
});

});

module.exports = router;

select.html

<!DOCTYPE html>
<html lang="en">

<head>
<meta charset="UTF-8">
<title>ajax</title>
</head>

<body>
<form action="/select" method="post">
<h5>查询</h5>
<input name="msg" type="text" id="msg">
<input name="submit" type="submit">
</form>
<div style="border:1px solid red;height:30px;margin-top:10px;line-height:30px;" id="select">

</div>
<div style="border:1px solid black;height:300px;margin-top:10px;line-height:30px;">

</div>
</body>

</html>
<script type="text/javascript">
var Id = "<%=result.id%>";
var name = "<%=result.name%>";
var result ="<%=result%>"

var select = document.getElementById("select");
if(result=="没找到相应数据")
{
select.innerHTML = result;
}
else
{
select.innerHTML = Id+" "+name;
}
</script>

add.js

var express = require('express');
var router = express.Router();
var Data = require("./db.js");

router.get('/', function(req, res, next) {

res.render('add.html', {result:""});

});

router.post('/',function(req, res){
// 获取前端数据
var add = new Data();
var data = [
req.body.id,
req.body.name,
req.body.phone,
req.body.addr,
req.body.username,
req.body.password
];

console.log(JSON.stringify(data));
var addsel = new Data();
// 查询数据是否存在
addsel.select(function(err,result){
var resultdata =false;
for ( var i = 0 ; i< result.length; i++) {
var str = result[i].id;
var b=req.body.id;
if (b==parseInt(str)){

resultdata = true;
}
}
if(resultdata){
var message = "id信息已经存在";
res.render('add.html', {result:message});
}
else{
// 若果数据不存在,那么就进行·插入操作·
add.add(data,function(err, result){
var addsel = new Data();
addsel.select(function(err,result){
var resultdata = false;
for (var i = 0 ; i< result.length; i++) {
var str = result[i].id;
var b=req.body.id;
if (b==parseInt(str)){
resultdata = true;
}
}

if (resultdata) {
var message = "信息已经插入";

res.render('add.html', {result:message});
}
});
});
}
});

});

module.exports = router;

add.html

<!DOCTYPE html>
<html lang="en">

<head>
<meta charset="UTF-8">
<title>ajax</title>
</head>

<body>
<form action="/add" method="post">
<h5>增加</h5>
<input name="id" placeholder="id"  type="text" >
<input name="name" placeholder="name" type="text" >
<input name="phone" placeholder="phone" type="text" >
<input name="addr" placeholder="addr" type="text" >
<input name="username" placeholder="username" type="text" >
<input name="password" placeholder="password" type="text" >
<input name="submit" type="submit">
</form>
<div style="border:1px solid black;height:300px;margin-top:10px;line-height:30px;">
<%= result%>
</div>
</body>

</html>

selectall.js

var express = require('express');
var router = express.Router();
var Data = require("./db.js");

router.get('/', function(req, res, next) {

var all = new Data();
// 查询所有数据
all.selectall(function(err,result){
res.render('all.html', {all:result});
});

});

module.exports = router;

all.html

<!DOCTYPE html>
<html lang="en">

<head>
<meta charset="UTF-8">
<title>ajax</title>
</head>

<body>
<div style="border:1px solid black;height:300px;margin-top:10px;line-height:30px;">
<% for(var i = 0; i<all.length;i++){%>
<%= all[i].id%>    <%= all[i].name%>    <%= all[i].phone%>    <%= all[i].addr%>    <%= all[i].username%>    <%= all[i].password%><br>
<%}%>
%>
</div>
</body>

</html>

updata.js

var express = require('express');
var router = express.Router();
var Data = require("./db.js");
const qs = require('qs');

router.get('/', function(req, res, next) {
//前端页面获取数据
var updataSql = new Data();
updataSql.select(function(err,result){

res.render('updata.html', {medata:result,udinfo:""});
});

});

router.post('/',function(req, res){
//获取前端信息
var data = {
"id":qs.parse(req.body.id),
//多层对象解析
"name" :qs.parse(req.body.name),
"phone" :qs.parse(req.body.phone),
"addr" :qs.parse(req.body.addr),
"username" :qs.parse(req.body.username),
"password" :qs.parse(req.body.password)
}
console.log(req.body.id);
var obj = req.body.obj;
var del = req.body.del;

//求对象长度
function objLength(obj){
var count = 0;
for(var i in obj){
count ++;
}
return count;
}
//获取id对象长度
var lh= objLength(data.id[0]);
//更新的信息
var info =[];

for(var i=0;i<lh;i++)
{
if(parseInt(data.id[i])==obj)
{
info[0]=data.name[i];
info[1]=data.phone[i];
info[2]=data.addr[i];
info[3]=data.username[i];
info[4]=data.password[i];
info[5]=data.id[i];

}

}
console.log(info);
console.log(obj);
console.log(del);
//req.body通过识别name属性 获得value值
var updata = new Data();
var updataSql = new Data();
var dele = new Data();
var udinfo;
//数据更新
if(obj!="none")
{
udinfo = "更改成功";
updata.updata(info,function(err,result){

updataSql.select(function(err,result){

res.render('updata.html', {medata:result,udinfo:udinfo});
});
});

}
// 数据删除
if(del!="none")
{

dele.dele(del,function(err,result){
var udinfo ="删除成功";
updataSql.select(function(err,result){
res.render('updata.html', {medata:result,udinfo:udinfo});
});
});
}

});

module.exports = router;

updata.html

<!DOCTYPE html>
<html lang="en">

<head>
<meta charset="UTF-8">
<title>ajax</title>
</head>

<body >
<form action="/updata" method="post">
<h5>更新--删除</h5>
<input name="submit" type="submit" value="获取数据" id="submit" style="display: none"><%= udinfo%>
<br>
<% for(var i=0;i<medata.length;i++){%>
<input name="id" placeholder="id"  type="text" id="id" value="<%=medata[i].id%>" readonly unselectable="on" >
<input name="name" placeholder="name" type="text" id="name" value="<%=medata[i].name%>">
<input name="phone" placeholder="phone" type="text" id="phone" value="<%=medata[i].phone%>">
<input name="addr" placeholder="addr" type="text" id="addr" value="<%=medata[i].addr%>">
<input name="username" placeholder="username" type="text" id="username" value="<%=medata[i].username%>">
<input name="password" placeholder="password" type="text" id="password" value="<%=medata[i].password%>">
<input type="button" id="<%= i%>" value="更新" onclick="mytr_id(this.id)">
<input type="button" id="<%= i%>" value="删除" onclick="mydel_id(this.id)">
<br>
<%}%>
<input type="text" name="obj" id="obj" value="none" style="display: none">
<input type="text" name="del" id="del" value="none" style="display: none">
</form>

</body>

</html>
<script type="text/javascript">
function mytr_id(self)
{

var obj =document.getElementById("obj");
obj.value = self;
var sub = document.getElementById("submit");
sub.click();

}
function mydel_id(self)
{
var del =document.getElementById("del");
del.value = self;
var sub = document.getElementById("submit");
sub.click();
}

</script>

核心部件
db.js 数据库连接的密码要手动输入

//连接数据库
var mysql = require('mysql');
//创建连接池
var pool = mysql.createPool({
host: 'localhost',
user: 'root',
password: '********',
database:'test'
});
// 封装数据对象
function Data()
{
// 定义查找成员函数
this.select = function(callback)
{
var sql = " select * from user";
pool.getConnection(function(conn_err, conn) {
if(conn_err) {
callback(err,null,null);
}
else {
conn.query(sql, function(query_err, result) {
if (query_err) {
console.log(" Error: " + query_err.message);
return;

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}
conn.release();
// 释放连接池
callback(query_err,result);
});
}
});
}
// 定义检索成员函数
this.selectall = function(callback)
{
var sql = " select * from user";
pool.getConnection(function(conn_err, conn) {
if(conn_err) {
callback(err,null,null);
}
else {
conn.query(sql, function(query_err, result) {
if (query_err) {
console.log(" Error: " + query_err.message);
return;
}
conn.release();
callback(query_err,result);
});
}
});

}

// 定义添加成员函数
this.add= function(data,callback)
{

var  addSql = 'INSERT INTO user(id,name,phone,addr,username,password) VALUES(?,?,?,?,?,?)';
pool.getConnection(function(conn_err, conn) {
if(conn_err) {
callback(err,null,null);
}
else {
conn.query(addSql,data, function(query_err, result) {
if (query_err) {
console.log(" Error: " + query_err.message);
return;
}
conn.release();
callback(query_err,result);
});
}
});
}

// 意义一个更新成员函数
this.updata= function(data,callback)
{

var  updataSql = 'UPDATE user SET name =?,phone=?,addr=?,username=?,password=? WHERE Id = ?';
pool.getConnection(function(conn_err, conn) {
if(conn_err) {
callback(err,null,null);
}
else {
conn.query(updataSql,data, function(query_err, result) {
if (query_err) {
console.log(" Error: " + query_err.message);
return;
}
conn.release();
callback(query_err,result);
});
}
});
}

// 定义删除对象
this.dele= function(data,callback)
{

var  delSql = 'DELETE FROM user where id=?';
pool.getConnection(function(conn_err, conn) {
if(conn_err) {
callback(err,null,null);
}
else {
conn.query(delSql,data, function(query_err, result) {
if (query_err) {
console.log(" Error: " + query_err.message);
return;
}
conn.release();
callback(query_err,result);
});
}
});
}
};

module.exports = Data;
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