如何在Node.js（express）上返回由{}代替[]而不是[]的json如果我對我的node.js（EXPRESS）API curl執行了curl請求，則返回使用knex和postgresql的查詢結果

Question

http://127.0.0.1:3000/api/events/user/id/1我得到這樣的結果：

[{"id":"1","name":"casamiento 1","description":"el casamiento del tio claudio","mode_id":1,"initial_date":"2016-05-28T22:14:57.000Z","end_date":"2016-05-28T22:14:58.000Z","state_id":1,"user_id":"1","location":"0101000020E61000000000000000805BC00000000000003E40"},{"id":"2","name":"casamiento 2","description":"el casamiento del tio claudio 2","mode_id":1,"initial_date":"2016-05-28T22:14:57.000Z","end_date":"2016-05-28T22:14:58.000Z","state_id":1,"user_id":"1","location":"0101000020E61000000000000000405BC00000000000003D40"},{"id":"3","name":"fiesta del sandwich de miga","description":"Nos juntamos a comer sandwiches de miga hasta reventar","mode_id":1,"initial_date":"2016-05-28T22:15:58.000Z","end_date":"2016-05-28T22:15:58.000Z","state_id":1,"user_id":"1","location":"0101000020E610000000000000000000000000000000804840"}] 

，我需要的輸出被大括號一樣包圍着：

{{"id":"1","name":"casamiento 1","description":"el casamiento del tio claudio","mode_id":1,"initial_date":"2016-05-28T22:14:57.000Z","end_date":"2016-05-28T22:14:58.000Z","state_id":1,"user_id":"1","location":"0101000020E61000000000000000805BC00000000000003E40"},{"id":"2","name":"casamiento 2","description":"el casamiento del tio claudio 2","mode_id":1,"initial_date":"2016-05-28T22:14:57.000Z","end_date":"2016-05-28T22:14:58.000Z","state_id":1,"user_id":"1","location":"0101000020E61000000000000000405BC00000000000003D40"},{"id":"3","name":"fiesta del sandwich de miga","description":"Nos juntamos a comer sandwiches de miga hasta reventar","mode_id":1,"initial_date":"2016-05-28T22:15:58.000Z","end_date":"2016-05-28T22:15:58.000Z","state_id":1,"user_id":"1","location":"0101000020E610000000000000000000000000000000804840"}} 

我的模型「事件」文件是這樣的，這使得查詢到knex然後返回結果：

var express = require('express'); 
var router = express.Router(); 
var Promise = require("bluebird"); 
var connectionString = 'postgres://postgres:postgres@localhost:5432/flock'; 
var knex = require('knex')({ 
    client: 'pg', 
    connection: connectionString, 
    searchPath: 'knex,public' 
}); 

//Get all events from a particular user 
exports.getUserEvents=function(id_user){ 



    console.log("Retrieving data from id_user: "+id_user); 

    var promise1 = Promise.try(function() { 
    return knex('events') 
     .select('*') 
     .where('user_id', id_user); 
    }); 

    var promise2=promise1.then(function (rows) { // this creates a new promise, and the promise created here is what gets returned to the caller 
     console.log('Returning '+rows.length+' rows from the user with id '+id_user); 
     return rows; 

    }); 

    return promise2; 
} 

和我的路由器文件，它調用模型文件功能getUserEvents，是這樣的：

var express = require('express'); 
var router = express.Router(); 
var Event=require('../models/event'); 


//get all events from a user 

router.get('/user/id/:id_user', function(req, res, next) { 

    var id_user= req.params.id_user; 

    var promise = Event.getUserEvents(id_user); 

    promise.then(function (result) { 
    console.log('Sending response'); 
    return res.json(result); //<---this line builds the JSON response 
    }); 

    promise.catch(function (err) { 


    return res.sendStatus(500); 

    }); 

}); 




module.exports = router 

我的問題是，如何發送由{}而不是【喜歡的包圍JSON對象名單現在回來了嗎？非常感謝您

編輯：這解決了我的問題，最終的格式爲{ 「行」：[{ROW1}，{ROW2}等]}

exports.getUserEvents=function(id_user){ 



    console.log("Retrieving data from id_user: "+id_user); 

    var promise1 = Promise.try(function() { 
    return knex('events') 
     .select('*') 
     .where('user_id', id_user); 
    }); 

    var promise2=promise1.then(function (rows) { // this creates a new promise, and the promise created here is what gets returned to the caller 
     console.log('Returning '+rows.length+' events from the user with id '+id_user); 
     return {rows};//<----This solved the issue 

    }); 

    return promise2; } 

Answer 1

您的API請求返回對象的數組

arrayOfObjects = [ 
    {objkey: objvalue}, 
    {objkey: objvalue} 
] 

你可以巢陣列中的物體這樣

newObj = { 
    nestedarray: result 
} 

或者你可以返回的對象作爲單獨的數值

newObj = { 
    1: result[0], 
    2: result[1], 
    3: result[2] 
} 

但是所有的對象都需要一個鍵值對。

請注意，JavaScript中的數組實際上是一種專用類型的對象，它仍然使用恰巧是整數的屬性名稱，但是已經過優化以允許特定的方法。

所以你的情況：

var express = require('express'); 
var router = express.Router(); 
var Event=require('../models/event'); 


//get all events from a user 

router.get('/user/id/:id_user', function(req, res, next) { 

    var id_user= req.params.id_user; 

    var promise = Event.getUserEvents(id_user); 

    promise.then(function (result) { 
    console.log('Sending response'); 

    // Option One 
    var newObj = { 
     nestedarray: result 
    } 

    // Option Two 
    var newObj = {} 
    response.forEach(function(elem, index) { 
     newObj[index] = elem; 
    }); 

    return res.json(newObj); //<---this line builds the JSON response 
}); 

    promise.catch(function (err) { 

     return res.sendStatus(500); 

    }); 
}); 

注意，在這兩個選項，你不想要，只是因爲它是不可能的格式結束，但任一選項擺脫了數組語法。

Answer 2

Asuming要處理的每個對象分別可以使用：

for (i in result){ 
    console.log(result[i]); 
} 

，將返回，對於例如您提供：

{"id":"1","name":"casamiento 1","description":"el casamiento del tio claudio","mode_id":1,"initial_date":"2016-05-28T22:14:57.000Z","end_date":"2016-05-28T22:14:58.000Z","state_id":1,"user_id":"1","location":"0101000020E61000000000000000805BC00000000000003E40"} 
and 
{"id":"2","name":"casamiento 2","description":"el casamiento del tio claudio 2","mode_id":1,"initial_date":"2016-05-28T22:14:57.000Z","end_date":"2016-05-28T22:14:58.000Z","state_id":1,"user_id":"1","location":"0101000020E61000000000000000405BC00000000000003D40"} 
and 
{"id":"3","name":"fiesta del sandwich de miga","description":"Nos juntamos a comer sandwiches de miga hasta reventar","mode_id":1,"initial_date":"2016-05-28T22:15:58.000Z","end_date":"2016-05-28T22:15:58.000Z","state_id":1,"user_id":"1","location":"0101000020E610000000000000000000000000000000804840"} 

注：{{東西：1}}，正如你提出的想要的輸出，不是有效的JSON。

Answer 3

在JSON中，[]括號包圍陣列。您的查詢返回一個數組，並且在您的行return res.json(result)中，結果變量是一個數組。讓它返回一個單獨的對象而不是一個數組，並且[]將會消失。如果您希望查詢包含多個結果並且仍然不想要數組，請將數組包裝在另一個對象中，如{newResult: result}，然後返回該結果。