節點JS快遞試圖一個ORM JSON傳遞到客戶端在我app.js

Question

question   = require('./routes/question_api'), 

    app.use(orm.express("mysql://root@127.0.0.1/daat", { 
     define: function (db, models, next) { 
      var question_model = db.define('questions', { 
       id    : Number, 
       ..... more definitions 
       } 
      }); 
      models.question = question_model; 
      next(); 
     } 
    })); 

在我question_api.js

var questions = require('../lib/questions/questions.js'); 

//NEW Question 
//Get Question by ID 
//Get Question By Category 

exports.list = function(req, res){ 
    res.json(questions.list_top_rates(req, res)); 
}; 

在我questions.js

exports.list_top_rates = function(req, res) { 
    var limit = req.limit || 20; 
    var final_result = {"1": {}}; 

    //Z means descending 
    req.models.question.find({}, limit, ["rating", "Z"], function(err, questions) { 
     final_result = questions; 
     return final_result[0]; 
    }); 
    return final_result; 
// return final_result; 
// return { 
//  1: "first question , limit is " + limit, 
//  2: "second question", 
//  3: "third question", 
//  4: "forth question" 
// } 
}; 

我得到空的結果。如果我直接從question_api.js返回，它會起作用。

Answer 1

我不知道你正在使用的庫，但考慮您將得到一個回調作爲參數，find可能是一個異步函數。你將不得不相應地更改代碼：

question_api.js：

exports.list = function(req, res){ 
    questions.list_top_rates(req, function(final_result) { 
     res.json(final_result); 
    }); 
}; 

questions.js：

exports.list_top_rates = function(req, callback /* the parameter res is not needed anymore */) { 
    var limit = req.limit || 20; 
    var final_result = {"1": {}}; 

    //Z means descending 
    req.models.question.find({}, limit, ["rating", "Z"], function(err, questions) { 
     final_result = questions; 
     callback(final_result[0]); 
    }); 
};