我基本上相信這個錯誤是由於我打電話的對象不包含.populate
函數,儘管我不知道如何改變它的工作。TypeError:populate(...)。exec不是函數
首先,這裏是完整的錯誤。
TypeError: exam[0].modules[u].topics[i].populate(...).exec is not a function
at /home/ubuntu/workspace/tests/app.js:425:84
at Query.Model.$wrapCallback (/home/ubuntu/workspace/tests/node_modules/mongoose/lib/model.js:3336:16)
at /home/ubuntu/workspace/tests/node_modules/mongoose/node_modules/kareem/index.js:259:21
at /home/ubuntu/workspace/tests/node_modules/mongoose/node_modules/kareem/index.js:127:16
at nextTickCallbackWith0Args (node.js:420:9)
at process._tickCallback (node.js:349:13)
Process exited with code: 1
我指的是具體線路是exam[0].modules[u].topics[i].populate("questions").exec(function(err,quests)
另一條線,我相信是顯著這裏重要的是,它返回exam
不包含.populate
功能行examBoard.find({name:req.body.examBoardName},function(err,exam)
。
我認爲這很大程度上取決於我缺乏經驗,而不是邏輯錯誤,但我不確定。
以下是包含錯誤的代碼部分。
app.post("/test",function(req,res)
{
console.log("\n\n\n\n")
var time = req.body.time;
var topicName = [req.body.topic1,req.body.topic2,req.body.topic3,req.body.topic4,req.body.topic5];
var topicsArray = [];
examBoard.find({name:req.body.examBoardName},function(err,exam)
{
if(err)
{
console.log(err);
}
else
{
for(var u=0;u<exam[0].modules.length;u++)
{
console.log("exam[0].modules[u]:\n"+exam[0].modules[u]);
console.log("req.body.moduleName:\n"+req.body.moduleName);
if(exam[0].modules[u].name==req.body.moduleName)
{
console.log("topicName[]:\n"+topicName[0]+"\n"+topicName[1]+"\n"+topicName[2]+"\n"+topicName[3]+"\n"+topicName[4]);
for(var i=0;i<exam[0].modules[u].topics.length;i++)
{
console.log("exam[0].modules[u].topics[i].name:\n"+exam[0].modules[u].topics[i].name);
for(var t=0;t<topicName.length;t++)
{
if(exam[0].modules[u].topics[i].name==topicName[t])
{
// exam[0].modules[u].topics[i].find({name:topicName[t]}).populate("questions").exec(function(err,quests)
exam[0].modules[u].topics[i].populate("questions").exec(function(err,quests)
{
if(err)
{
console.log(err);
}
else
{
console.log("exam[0].modules[u].topics[i].questions:\n"+exam[0].modules[u].topics[i].questions);
topicsArray.push({
name:topicName[i],
questions:quests
});
}
});
}
}
}
break;
}
}
}
});
});
這裏是examBoard
模式。
var mongoose = require("mongoose");
var topicSchema = new mongoose.Schema({
name: String,
questions:[
{
type:mongoose.Schema.Types.ObjectId,
ref:"question"
}
],
});
var moduleSchema = new mongoose.Schema({
name: String,
topics: [topicSchema]
});
var examBoardSchema = new mongoose.Schema({
name: String,
modules: [moduleSchema]
});
module.exports = mongoose.model("examBoard", examBoardSchema);
而這裏只是爲了防止這裏可能出現問題,導入模式。
var express = require("express"),
mongoose = require("mongoose"),
passport = require("passport"),
bodyParser = require("body-parser"),
LocalStrategy = require("passport-local"),
passportLocalMongoose = require("passport-local-mongoose"),
seedDB = require("./seeds"),
question = require("./models/question"),
examBoard = require("./models/examBoard"),
user = require("./models/user");
它肯定會在所有模塊中的所有主題中填充所有問題,儘管在數據庫增長時它的效率會非常低。 我想你提到了這一點,但是當你說把它從for循環中移出來時,我不確定這將如何阻止它填充所有內容,你能舉個例子嗎? –
@ JonathanWoollett-light檢查我的回答,上面用你的用例編輯。 –
Thnak你,這是我認爲我只需要學習存在的東西。 –