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我正在尝试按照http://www.gianlucaguarini.com/blog/push-notification-server-streaming-on-a-mysql-database/上的“教程”来习惯 node 和 node+mysql。但是，它在使用完全相同的代码时会引发错误：

C:\node\testproject>node index.js
   info  - socket.io started
{ [Error: connect ECONNREFUSED]
  code: 'ECONNREFUSED',
  errno: 'ECONNREFUSED',
  syscall: 'connect',
  fatal: true }

我正在使用 usbwebserver，其中我在端口 8080 上创建了一个数据库，而代码正在监听 8000。所以我尝试将其更改为 8000，但无济于事。这样做的错误略有不同：

C:\node\testproject>node index.js
   info  - socket.io started
   warn  - error raised: Error: listen EADDRINUSE
{ [Error: connect ECONNREFUSED]
  code: 'ECONNREFUSED',
  errno: 'ECONNREFUSED',
  syscall: 'connect',
  fatal: true }

我使用与上述教程完全相同的代码。但这里供参考：

var app                 = require('http').createServer(handler),
    io                  = require('socket.io').listen(app),
    fs                  = require('fs'),
    mysql               = require('mysql'),
    connectionsArray    = [],
    connection          = mysql.createConnection({
        host        : 'localhost',
        user        : 'root',
        password    : 'usbw',
        database    : 'nodejs'
    }),
    POLLING_INTERVAL = 3000,
    pollingTimer;

// If there is an error connecting to the database
connection.connect(function(err) {
  // connected! (unless `err` is set)
  console.log( err );
});

// creating the server ( localhost:8000 )
app.listen(8000);

// on server started we can load our client.html page
function handler ( req, res ) {
    fs.readFile( __dirname + '/client.html' , function ( err, data ) {
        if ( err ) {
            console.log( err );
            res.writeHead(500);
            return res.end( 'Error loading client.html' );
        }
        res.writeHead( 200 );
        res.end( data );
    });
}

/*
*
* HERE IT IS THE COOL PART
* This function loops on itself since there are sockets connected to the page
* sending the result of the database query after a constant interval
*
*/

var pollingLoop = function () {

    // Doing the database query
    var query = connection.query('SELECT * FROM users'),
        users = []; // this array will contain the result of our db query

    // setting the query listeners
    query
    .on('error', function(err) {
        // Handle error, and 'end' event will be emitted after this as well
        console.log( err );
        updateSockets( err );
    })
    .on('result', function( user ) {
        // it fills our array looping on each user row inside the db
        users.push( user );
    })
    .on('end',function(){
        // loop on itself only if there are sockets still connected
        if(connectionsArray.length) {
            pollingTimer = setTimeout( pollingLoop, POLLING_INTERVAL );

            updateSockets({users:users});
        }
    });

};


// creating a new websocket to keep the content updated without any AJAX request
io.sockets.on( 'connection', function ( socket ) {

    console.log('Number of connections:' + connectionsArray.length);
    // starting the loop only if at least there is one user connected
    if (!connectionsArray.length) {
        pollingLoop();
    }

    socket.on('disconnect', function () {
        var socketIndex = connectionsArray.indexOf( socket );
        console.log('socket = ' + socketIndex + ' disconnected');
        if (socketIndex >= 0) {
            connectionsArray.splice( socketIndex, 1 );
        }
    });

    console.log( 'A new socket is connected!' );
    connectionsArray.push( socket );

});

var updateSockets = function ( data ) {
    // adding the time of the last update
    data.time = new Date();
    // sending new data to all the sockets connected
    connectionsArray.forEach(function( tmpSocket ){
        tmpSocket.volatile.emit( 'notification' , data );
    });
};

提前致谢！

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