javascript - ReferenceError: 'pictures' 未定义。使用 Node.js

Question

找遍了所有地方，但无法运行。我是新来的，所以对我来说搜索或修复正确的东西也有点困难。尝试从数据库中获取数据，但图片变量未定义，它说，我之前运行过它，也许只是类似的类型错误，但我已经尝试了很多东西，我的学校项目已经没有时间了。这是我的代码:

索引.ejs:

<main>
    <div class="jumbotron">
        <h1>Formula 1, see it, feel it!</h1></br>
        <p>Welkom! Op deze site vind u de meest mooie foto's van de Formule 1.</p>
    </div>
</main>

<div class="jumbotron">

       <% if(pictures.length){ %>     
<table>
    <tr>
        <th>Titel</th>
        <th>Locatie</th>
        <th>Datum</th>
        <th>Naam</th>
        <th>Waardering</th>

    </tr>
        <% } %>
        <% for (var i = 0; i < pictures.length; i++) { %>
    <tr>

        <td><%= pictures[i].titel %></td>
        <td><%= pictures[i].locatie %></td>
        <td><%= pictures[i].datum %></td>
        <td><%= pictures[i].naam %></td>
        <td><%= pictures[i].waardering %></td>
        <% } %>
    </tr>                   
</table>    

</div>

<footer>
    <% include ../partials/footer %>
</footer>

index.js

    var express = require('express');
var router = express.Router();

router.get('/', function(req, res) {
    req.getConnection(function(err, connection) {
        connection.query('SELECT * FROM pictures', function(err, results) {
            res.locals.pictures = results;
            console.log(results);
            res.render('../views/pages/index');
        });
    });
});

module.exports = router;

app.js:

var express = require('express'),
    path = require('path'),
    favicon = require('serve-favicon'),
    logger = require('morgan'),
    cookieParser = require('cookie-parser'),
    flash = require('connect-flash'),
    expressValidator = require('express-validator'),
    session = require('express-session'),
    passport = require('passport'),
    LocalStrategy = require('passport-local').Strategy,
    bodyParser = require('body-parser'),
    multer = require('multer'),
    mongo = require('mongodb'),
    mongoose = require('mongoose'),
    mysql = require('mysql'),
    myConnection = require('express-myconnection');

var db = mongoose.connection;

var dbOptions = {
    host: 'localhost',
    user: 'fcdeen_user',
    password: 'wEvGT9ctm8KUxdTD',
    database: 'fcdeen'
};

var indexRoutes = require('./routes/index'),    
    loginRoutes = require('./routes/login'),
    uploadRoutes = require('./routes/upload');

var app = express();

//Use session
app.use(session({
  secret: "Its_A_veRy_DarK_SecreT",
  resave: false,
  saveUninitialized: true
}));

// Voeg de bodyparser middleware aan de app toe (POST requests)
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({extended: true}));

// set the view engine to ejs
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'ejs');

// Voeg connectie middleware toe aan app
app.use(myConnection(mysql, dbOptions, 'single'));

// index page 
app.get('/home', function(req, res) {
    res.render('pages/index');
});

// index page 
app.get('/index', function(req, res) {
    res.render('pages/index');
});

// upload page 
app.get('/upload', function(req, res) {
    res.render('pages/upload');
});

// login page 
app.get('/login', function(req, res) {
    res.render('pages/login');
});

app.listen(8080);
console.log('Launch at port 8080');

这是错误:

ReferenceError: C:\School\SSS 2015\testen\node-ejs-master\views\pages\index.ejs:21
   19| <div class="jumbotron">
   20|   
>> 21|   <% if(pictures.length){ %>     
   22| <table>
   23| <tr>
   24| <th>Titel</th>

pictures is not defined
   at eval (eval at <anonymous> (C:\School\SSS 2015\testen\node-ejs-master\node_modules\ejs\lib\ejs.js:242:14), <anonymous>:33:292)
   at eval (eval at <anonymous> (C:\School\SSS 2015\testen\node-ejs-master\node_modules\ejs\lib\ejs.js:242:14), <anonymous>:35:68)
   at C:\School\SSS 2015\testen\node-ejs-master\node_modules\ejs\lib\ejs.js:255:15
   at Object.exports.render (C:\School\SSS 2015\testen\node-ejs-master\node_modules\ejs\lib\ejs.js:293:13)
   at View.exports.renderFile [as engine] (C:\School\SSS 2015\testen\node-ejs-master\node_modules\ejs\lib\ejs.js:323:20)
   at View.render (C:\School\SSS 2015\testen\node-ejs-master\node_modules\express\lib\view.js:126:8)
   at tryRender (C:\School\SSS 2015\testen\node-ejs-master\node_modules\express\lib\application.js:639:10)
   at EventEmitter.render (C:\School\SSS 2015\testen\node-ejs-master\node_modules\express\lib\application.js:591:3)
   at ServerResponse.render (C:\School\SSS 2015\testen\node-ejs-master\node_modules\express\lib\response.js:961:7)
   at C:\School\SSS 2015\testen\node-ejs-master\app.js:61:6
   at Layer.handle [as handle_request] (C:\School\SSS 2015\testen\node-ejs-master\node_modules\express\lib\router\layer.js:95:5)
   at next (C:\School\SSS 2015\testen\node-ejs-master\node_modules\express\lib\router\route.js:131:13)
   at Route.dispatch (C:\School\SSS 2015\testen\node-ejs-master\node_modules\express\lib\router\route.js:112:3)
   at Layer.handle [as handle_request] (C:\School\SSS 2015\testen\node-ejs-master\node_modules\express\lib\router\layer.js:95:5)
   at C:\School\SSS 2015\testen\node-ejs-master\node_modules\express\lib\router\index.js:277:22
   at Function.process_params (C:\School\SSS 2015\testen\node-ejs-master\node_modules\express\lib\router\index.js:330:12)
   at next (C:\School\SSS 2015\testen\node-ejs-master\node_modules\express\lib\router\index.js:271:10)
   at C:\School\SSS 2015\testen\node-ejs-master\node_modules\express-myconnection\lib\express-myconnection.js:123:9
   at Layer.handle [as handle_request] (C:\School\SSS 2015\testen\node-ejs-master\node_modules\express\lib\router\layer.js:95:5)
   at trim_prefix (C:\School\SSS 2015\testen\node-ejs-master\node_modules\express\lib\router\index.js:312:13)
   at C:\School\SSS 2015\testen\node-ejs-master\node_modules\express\lib\router\index.js:280:7
   at Function.process_params (C:\School\SSS 2015\testen\node-ejs-master\node_modules\express\lib\router\index.js:330:12)

感谢您的帮助!

Answer 1

我认为这就是您问题的解决方案

// Don't separate the routes. If you are setting your routes in this file, try keep every route at the same file.

app.get('/', function(req, res) {
    req.getConnection(function(err, connection) {
        connection.query('SELECT * FROM pictures', function(err, results) {
            res.locals.pictures = results;
            console.log(results);
            res.render('pages/index', {pictures : results});
        });
    });
});

// index page 
app.get('/home', function(req, res) {
    res.render('pages/index');
});

// index page 
app.get('/index', function(req, res) {
    res.render('pages/index');
});

当您输入 /home 或 /index 时，您必须看到错误，但输入 / 应该不会有问题。

如果您尝试这三个路由执行相同的操作，您可以尝试以下操作:

app.get('/', renderPageIndex)

// index page 
app.get('/home', renderPageIndex)

// index page 
app.get('/index', renderPageIndex )

function renderPageIndexfunction(req, res) {
    req.getConnection(function(err, connection) {
        connection.query('SELECT * FROM pictures', function(err, results) {
            res.locals.pictures = results;
            console.log(results);
            res.render('pages/index', {pictures : results});
        });
    });
});