如何从多个嵌入的collections中获取数据到ejs？

Question

大家好，这个问题有点傻，但我是编程新手。因此，我一直在使用 ejs、nodejs、express、mongoose mongodb 为我的大学项目开发产品管理系统。所以我无法弄清楚如何获取类别标题而不是 objectId。我尝试使用 <td> <%= issue.product.category.title%></td> 但它变成空白。

图片供参考。

enter image description here

Ejs 代码。

<table class="table table-bordered">
  <thead class="bg-dark text-center">
    <tr class="text-white">
      <th>Employee Name</th>  
      <th>Email</th>  
      <th>Employee Number</th>  
      <th>Contact Number</th>   
      <th>Product ID</th>
      <th>Title</th>
      <th>Manufacturer</th>
      <th>Status</th>
      <th>Category</th>
      <th>Date/Time</th>
    </tr>
  </thead>
  <tbody class="text-center">
    <% if (issue.length> 0) { %> <% issue.forEach(issue=> { %>
    <tr>
      <td> <%= issue.ename %></td> 
      <td><%= issue.email  %></td>  
      <td><%= issue.enumber %></td>  
      <td><%= issue.cnumber %></td>  
      <td><%= issue.product.prodid%></td>
      <td><%= issue.product.title%></td>
      <td><%= issue.product.manufacturer%></td>
      <td><%= issue.product.status%></td> 
      <td> <%= issue.product.category%></td>
      <td><%= issue.issueTime %> </td>
      <% }) %> <% } else { %>

      <p>There are no issue to display...</p>

      <% } %>
    </tr>
  </tbody>
</table>

发行模型

const issueSchema = new Schema({
ename: {
    type: String,
    required: true
},
email: {
    type: String,
    required: true
},
enumber: {
    type: String,
    required: true
},
cnumber: {
    type: String,
    required: true
},
desig: {
    type: String,
    required: true
},
department: {
    type: String,
    required: true
},
description: {
    type: String,
    required: true
},  
product: {
    type: mongoose.Schema.Types.ObjectId,
    ref: 'Prodcut'
},
issueTime: {
    type: Date,
    default: Date.now()
}

});

const Issue = mongoose.model('issue',issueSchema);

module.exports = 问题；

这里，我嵌入了产品collection。

产品型号

const productSchema = new Schema({
prodid: {
    type: String,
    required: true
},
title: {
    type: String,
    required: true
},
manufacturer: {
    type: String,
    required: true
},
category: {
    type: mongoose.Schema.Types.ObjectId,
    ref: 'category'
},
status: {
    type: String,
    default: 'In Stock'
},
coverImage: {
    type: Buffer,
    required: true
},
coverImageType: {
    type: String,
    required: true
}

}, { 时间戳: true });

类别模型

const CategorySchema = new Schema({
title: {
    type: String,
    required: true
}

}, { 时间戳: true });

常量类别 = mongoose.model('category',CategorySchema);

module.exports = 类别；

现在这是我获取数据的 issueController。

const issue_detail = (req, res) => {
Issue.find().sort({ createdAt: -1})
.populate('product category')
.then((issue) => {
        res.render('products/issue/details', {
            issue: issue,
          })
})
.catch((err) => {
    console.log(err);
})

};

提前谢谢你！

Answer 1

单从代码上说有点难。

console.log 你从数据库中得到的东西会有帮助，所以在 ejs 的头部只是 pus

<% console.log(issues) %>

这会将返回的对象显示到您的视图中，您将从那里看到返回的内容，然后您可以在对象中引用正确的元素。

Answer 2

const issue_detail = (req, res) => {
Issue.find().sort({ createdAt: -1})
.populate({path : 'product', populate : {path : 'category'}})
.then((issue) => {
        res.render('products/issue/details', {
            issue: issue,
          })
})
.catch((err) => {
    console.log(err);
})

参考：http://mongoosejs.com/docs/populate.html#deep-populate

如何从多个嵌入的collections中获取数据到ejs？

How to get the data from multiple embbedded collections into ejs?

ejs

mongoose

mongodb

node.js

express