Question

我正在尝试在node.js中编写一个简单的Web应用程序，它允许用户将数据输入搜索栏，然后将输入发送到服务器，服务器将使用用户生成的输入查询数据库。我已经设置并连接了我的数据库，但这是我的代码：

服务器

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

//Configure application
app.set('views',__dirname + '/views'); //Set views directory
app.use(express.static(__dirname + '/JS'));
app.set('views engine', 'ejs'); //Set view engine to ejs
app.engine('html', require('ejs').renderFile);
app.use(function(req, res, next){ //Set no cache for the server
  res.header('Cache-Control', 'private, no-cache, no-store, must-revalidate');
  res.header('Expires', '-1');
  res.header('Pragma', 'no-cache');
  next();
})

//Connect to mySQL database
var db = sql.createConnection({
  host: 'localhost',
  user: 'root',
  password: 'root',
  database: 'homeDB'
});
db.connect(function(err){
  if(err){console.log('there was an error connecting to the database' + err);}
})

//Set up routers (request handlers)

//Return home page when root('/') is requsted
app.get('/', function(req, res){
  res.render('index.html');
});

app.get('/search', function(req, res){ //GET method to access DB and return results in JSON
  db.query('SELECT * FROM products WHERE product LIKE "%' + req.query.key + '%"',
  function(err, rows, fields){
    if(err) throw err;
    var data = [];
    for(i=0;i<rows.length;i++){
      data.push(rows[i].product);
    }
    res.end(JSON.stringify(data));
  });
});

app.get('/typeahead.bundle.js', function(req, res){ //When typeahead is requested, send it to client
var fileName = './typeahead.bundle.js';
  var options = {
    cacheControl: false,
    root: __dirname
  }
  res.sendFile(fileName, options, function(err){
    if(err){
      console.log('there was an error sending ' + fileName + err);
      res.status(err.status).end();
    }else{console.log('Sent! ' + fileName);}
  });
});

app.post('/search', function(req, res){ //POST method to access DB and return results in JSON
  db.query('SELECT * FROM products WHERE product LIKE "%' + req.params.input + '%"',
  function(err, rows, fields){
    if(err) throw err;
    var data = [];
    for(i=0;i<rows.length;i++){
      data.push(rows[i].product);
    }
    res.end(JSON.stringify(data));
    console.log(req.params.input);
  });
});

var server = app.listen(3000, function(){ //Start the server on port 3000
  console.log('server has started on localhost:3000...')
});

HTML

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>Express Application</title>
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
    <script src="/typeahead.bundle.js" type="text/javascript"></script>
  </head>
  <body>
    <h1>Thank you for connecting to my server!</h1>

    <form class="search" action="typeahead" method="post">
      <input class="form-control typeahead tt-query" type="text" name="input" placeholder="Search">
      <input class="btn btn-primary" type="submit" name="input" value="Submit">
    </form>

    <script type="text/javascript">
      $(document).ready(function(){
        $('input.typeahead').typeahead({
          name: 'typeahead',
          remote: 'http://localhost:3000/search?key=%QUERY',
          limit: 10
        });
      });
    </script>
  </body>
</html>

现在我在节点中设置了所有路由器和中间件，但我似乎无法弄清楚如何简单地将用户输入发送到服务器。我尝试使用'req.query.key'来获取搜索输入的值，但实际上在我的情况下返回为undefined。那么，无论如何通过'req.query.key'变量实际接收文本，还有一个更“传统”的方法来制作一个简单的数据库搜索栏吗？

P.S。我对Express和Node.js整体编程仍然很陌生，所以如果您发现任何常见错误或“草率”代码，我很乐意听取您的反馈意见。

Answer 1

您是否尝试过以下方式获取参数

var key = request.options.key || (request.options.where && request.options.where.key) || request.param('key');

Answer 2

您可以尝试使用npm body-parser，代替req.params.key，您可以放置req.body.input（其中input是输入元素的名称）。

把这个：

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

在模板引擎配置之前（在设置视图之前）

搜索数据库| NodeJS，Express，HTML

2 个答案: