var nodePort = 3030;
var express = require('express');
var app = express();
var bodyParser = require('body-parser');
var db = require('mysql');
var dbPool = db.createPool({
    host : 'localhost',
    user : 'root',
    password : '1234',
    database : 'test',
    port : 3306
});


app.use( bodyParser.json() );
app.get('/api/db', function(req, res){
    res.setHeader('content-type', 'application/json');
    dbPool.getConnection(function(objErr, objConn){
        if(objErr){
            sendError(res, 503, 'error', 'connection', objErr); //503 - Service Unavailable
        }else{
            objConn.query("SELECT * FROM person", function(Err, Rows, Fields){
                if(Err){
                    sendError(res, 500, 'error', 'query', Err);
                }else{
                    res.send({
                        results : 'success',
                        err : '',
                        err_type : '',
                        fields : Fields,
                        rows : Rows,
                        length : Rows.length
                    });
                    objConn.release();
                }//else
            });
        }//else
    });
});
/*
app.get('/api/db:id', function(req, res){
    var id = req.params.id;
    res.setHeader('content-type', 'application/json');
    dbPool.getConnection(function(objErr, objConn){
        if(objErr){
            sendError(res, 503, 'error', 'connection', objErr); //503 - Service Unavailable
        }else{
            objConn.query("SELECT * FROM person WHERE id = ? ",[id], function(Err, Rows, Fields){
                if(Err){
                    sendError(res, 500, 'error', 'query', Err);
                }else{
                    res.send({
                        results : 'success',
                        err : '',
                        err_type : '',
                        fields : Fields,
                        rows : Rows,
                        length : Rows.length
                    });
                    objConn.release();
                }//else
            });
        }//else
    });
});
*/
app.post('/api/db', function(req, res){
    if(!req.body.tableName){
        var data = {
            ID : req.body.id,
            Name : req.body.name
        }
        tableName = 'person';
    }else{
        var data = {
            email : req.body.email,
            regid : req.body.regid
        }
        tableName = 'users';
    }//else
    console.log(req.body.regid);
    console.log(req.body.tableName);
    console.log(req.body.email);
    res.setHeader('content-type', 'application/json');
    dbPool.getConnection(function(objErr, objConn){
        if(objErr){
            sendError(res, 503, 'error', 'connection', objErr); //503 - Service Unavailable
        }else{
            objConn.query("INSERT INTO "+tableName+" SET ? ", data, function(Err, Rows, Fields){
                if(Err){
                    sendError(res, 500, 'error', 'query', Err);
                }else{
                    res.send({
                        results : 'success'
                    });
                    objConn.release();
                    if(!req.body.tableName){ gcmSend(); }
                }//else
            });
        }//else
    });
});

app.put('/api/db', function(req, res){
    var id = req.body.id;
    var data = {
        Name : req.body.name
    }
    res.setHeader('content-type', 'application/json');
    dbPool.getConnection(function(objErr, objConn){
        if(objErr){
            sendError(res, 503, 'error', 'connection', objErr); //503 - Service Unavailable
        }else{
            objConn.query("UPDATE person SET ? WHERE ID = ? ", [data,id], function(Err, Rows, Fields){
                if(Err){
                    sendError(res, 500, 'error', 'query', Err);
                }else{
                    res.send({
                        results : 'success'
                    });
                    objConn.release();
                    gcmSend();
                }//else
            });
        }//else
    });
});

app.delete('/api/db/:id', function(req, res){

    var id = req.params.id;
    res.setHeader('content-type', 'application/json');
    dbPool.getConnection(function(objErr, objConn){
        if(objErr){
            sendError(res, 503, 'error', 'connection', objErr); //503 - Service Unavailable
        }else{
            objConn.query("DELETE FROM person WHERE ID = ? ",[id], function(Err, Rows, Fields){
                if(Err){
                    sendError(res, 500, 'error', 'query', Err);
                }else{
                    res.send({
                        results : 'success'
                    });
                    objConn.release();
                    gcmSend();
                }//else
            });
        }//else
    });
});

function gcmSend(){

    message = new gcm.Message({
        collapseKey: 'demo',
        delayWhileIdle: true,
            timeToLive: 3,
            data: {
                title: 'Node.js den mesaj gönderildi'
            }
    });
    sender.send(message, registrationIds, 4, function (err, result) {
        console.log(result);
    });
}

function sendError(res, iStatusCode, strResult, strType, objError){
    res.send({
        results : strResult,
        err : objError.type,
        err_type : strType
    });
}

app.listen(nodePort);
console.log('App listening on port' + nodePort);

最佳答案

需要说明的是-Node.js是而不是单线程。您的应用程序代码是在一个线程中执行的，但是在后台它会在需要时使用它们-看一看here(答案和下面的注释):

To a Javascript program on node.js, there is only one thread.

If you're looking for technicalities, node.js is free to use threads to solve asynchronous I/O if the underlying operating system requires it.

As far as the user of node.js (ie the Javascript programmer) is involved, the abstraction is that there is only a single thread. In the case of the underlying runtime (v8), it uses threads internally for - for example - profiling, and it may do so freely as long as it doesn't leak that information up to the Javascript.

In other words, if you dive down inside the actual runtime, you will find more than one thread helping to keep the single Javascript thread running smoothly.

Connections are lazily created by the pool. If you configure the pool to allow up to 100 connections, but only ever use 5 simultaneously, only 5 connections will be made. Connections are also cycled round-robin style, with connections being taken from the top of the pool and returning to the bottom.

When a previous connection is retrieved from the pool, a ping packet is sent to the server to check if the connection is still good.

关于javascript - Node js(getConnection)，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/26118700/