Question

如何在nodejs中应用分页的概念。我发布了我的整个nodejs 练习模块，但我坚持分页的概念。我需要每页显示4个条目。的前端

<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<body>
<form action="/deletechecks" method="post">
<table style="margin-top: 20px" table border="1"  text- 
align:ccellspacing="20px" cellpadding="15px" width="100%">
<% for(var i = 0 ; i < data.length ; i++) { %>
    <tr></td>
        <td> <%= data[i].catname %> </td>
        <td> <%= data[i].status %> </td>
        <td> <%= data[i].id %> </td>
        <td> <a href="/delete/<%= data[i].id %>"> delete</a></td>
        <td> <a href="/view/<%= data[i].id %>"> view</a></td>
        <td> <a href="/update/<%= data[i].id %>"> update</a></td>
        <td> <input type="checkbox" name="check" value="<%= data[i].id 
        %>">delete <%=data[i].id %>  </td>
       </tr>
       <% } %>
       </table>
       <input type="submit" name="submit" value="Delete Selected">

       </div>
       </form>
       </body>
       </html>

后端

    var express= require('express');
    var app = express();
    var url = require('url')
    var bodyparser= require('body-parser');
    var mysql = require('mysql');
    var session= require('express-session');
    app.use(session({secret:'hello'}));

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

    app.set ("view engine" , 'ejs');


    var con = mysql.createConnection({
   host: "localhost",
    user:'root',
    password: "",
   database:'blog'
    });
   con.connect(function(err) {
 if(err) throw err;
 console.log("connected!");
  });
app.get('/',function(req,res){
res.render('blog1');
 });
app.post('/action',function(req,res){
var title=req.body.cat;
var status =req.body.sel ;
var q = "insert into category set catname = '"+title+"', 
status='"+status+"'";
con.query(q,function(err,result){
    if(err)
        throw err;
    else
    res.redirect('/viewdata');

   });
   });
   app.get('/viewdata', function(req,res) {
   var w= "select * from category";
   con.query(w, function(err,result){
   res.render('showdata',{data:result});

  });
  });

  app.get('/delete/:a',function(req,res){
  var z= req.params.a;
     var d= "delete from category where id='"+z+"'";
 con.query(d,function(err,result){
    if(err) throw err;
    res.redirect('/viewdata');
 });

 });
app.get('/view/:a',function(req,res){
var z= req.params.a;// url se dynamic value nikalne ke liye
var d= "select * from category where id='"+z+"' ";
con.query(d,function(err,result) {
if(err) throw err;
res.render('showbyid',{data:result});
});
});
app.get('/update/:id', function(req,res){
var d= req.params.id
var z= "select * from category where id='"+d+"'";
con.query(z,function(err,result) {
    if(err) throw err;
    res.render('blog1', {data:result});
});
});
app.post('/new_action/:id',function(req,res){
 var x = req.body.cat;
 var y = req.body.sel;
 var z = req.params.id;
 var updated ="update category set catname ='"+x+"', status='"+y+"' where 
 id='"+z+"' ";
 con.query(updated,function(err,result){
    if(err)
        throw err;
    else
        res.redirect('/viewdata');
 });
 });
app.get('/viewdata',function(req,res){
var q= "select * from category";
con.query(q,function(err,result){
    res.render("viewdata",{data:result});

});
});

app.post('/deletechecks',function(req,res){
var ch = req.body.check;
if(typeof ch == "string")
{
    var h= "delete from category where id='"+ch+"'";
        console.log(h);     
        con.query(h,function(err,result)
        {
            console.log('deleted');
        });
}   
else
{
    for( var i=0;i<ch.length;i++)
    {
        var h= "delete from category where id='"+ch[i]+"'";
        console.log(h);     
        con.query(h,function(err,result)
        {
            console.log('deleted');
        });
    }
 } 
  res.redirect('/viewdata');
 });
app.get('/login',function(req,res){
if(req.session.name)
{
    res.redirect("/dashboard");
}
else {
res.render('login');
}
});
 app.post('/new',function(req,res){
 var email = req.body.emailfield;
 var password = req.body.passwordfield;
 var updated ="  select count (email) as val  from  admin where email = 
 '"+email+"' and password='"+password+"' and status='active'";
 con.query(updated,function(err,result){
    if(err)
        throw err;
    if(result[0].val)//
    {
        req.session.name=email;
        res.redirect("/dashboard");
    }

    else
    {
        res.redirect("/login");
    }
    });
    });
    app.get("/dashboard",function(req,res)
    {
   if(!req.session.name)
    {
    res.redirect("/login");
   }
   res.render("dashboard")
    });
   app.get("/logout" , function(req,res){
  })

  app.listen(8080);

**还包括插入数据库的代码以及删除和其他操作。代码在其余部分工作完美查询只在这里应用分页的概念。 **

Answer 1

这与节点js无关。这是一个应用程序设计问题。分页以两种方式实现

客户端。获取整个数据集并将您的响应分页以显示前4，技术上将是数据[0]到数据[3]。
点击下一页，得到4到7，或者如果你有页面（data.length / 4），你得到数据[（第1页）* 4]到数据[（第1页）* 4 + 3]

服务器端：

   app.get('/viewdata/:page', function (req, res) {
     var page = req.params.page
     var w = //some SP to get nth page data;
     con.query(w, function (err, result) {
        res.render('showdata', { data: result });
     });
  });

nodejs中的分页，表达

1 个答案: