如何根据输入字段/文本从 mongoDB 查询/获取数据

Question

你好。感谢您点击这篇文章。我想知道如何根据输入字段从 mongodb 获取/查询数据。例如，如果我在名为“位置”的输入字段中输入“美国”，它将只获取其中包含美国的数据，并且数据将显示在下一页上。 当我点击一个按钮时，我如何让它工作。 我将链接我的网站和代码的一些屏幕截图（我感觉我的代码完全错误。）

error im facing after pasting ur code and code for passing data

this is my home.component.html line40. it is to pass the data to next page

home page where i will be inserting a country in the enter country field, once i click on "find" it will GET data from mongo based on the country ive insertted.

this is the page where the data will be displayed

这是我试图弄乱的一些代码（尚未测试是否有效）

 //this is in my api.js file
//get data from "listing"(which is my db collection) based on "inputcountry( the inputfield)"
router.get('/home', function(req, res) {
    db.collection('listing').find({"inputCountry": req.body.inputCountry}).toArray( (err, results) => {
        console.log('got search')
        res.send(results)});
    });


//this is in my service .ts file (named getservice)
//this is for the searching of house based on location
  searchHouse() {
    return this.http.get<any[]>('./api/home');
    }
    
    //this is in my home. component.ts file (where the searching will happen)
     constructor(private fb: FormBuilder, private router: Router, private getService: GetService) {
  // Retrieve posts from the API
    this.getService.searchHouse().subscribe(searchedhouses => {
    this.searchedhouses = searchedhouses;
  });
  }
  

<!--this is in my home.component.html where there is the input field named "inputcountry" and submit button -->

 <form [formGroup] = "myForm" (ngSubmit) = "searchHouse (myForm)">
            <div class="form-group">
            <label for="inputCountry">Enter Country</label>
            <input type="text" class="form-control"  formControlName="inputCountry" id="inputCountry"   name = "inputCountry" placeholder="Location e.g Singapore              .">
            </div>
            
              <button class="btn btn-lg btn-primary btn-block text-uppercase" routerLink="/houses" type="submit" >Find</button>
     
            </form>
            

Answer 1

您需要使用正则表达式才能根据您的输入字段在 mongodb 中搜索数据。

https://docs.mongodb.com/manual/reference/operator/query/regex/

Answer 2

好吧，按照代码，

在后端代码中，对于 api，您可以放置​​一个 Regexified 输入， 对于预期的输出，

router.get('/home', function(req, res) {
    db.collection('listing').find({"inputCountry": { $regex: req.query.inputCountry ,$options: 'i' }}).toArray( (err, results) => {
        console.log('got search')
        res.send(results)});
    });

上面的代码将在输出中为您提供结果。您可以在下一页显示的可能在前端。

在 Angular 中，有很多更好的方法可供简而言之，您可以执行以下操作：

 onSubmit = function (allValues) {
    console.log(allValues);
    this.http.get("http://localhost/home?inputCountry="+allValues.inputCountry).subscribe((data) => {
   //you will get the result here, show that to user. 
});
  };


<form [formGroup]="myForm" (ngSubmit)="onSubmit(myForm.value)">
  <div class="form-group">
    <label for="inputCountry">Enter Country</label>
    <input
      type="text"
      class="form-control"
      formControlName="inputCountry"
      id="inputCountry"
      name="inputCountry"
      placeholder="Location e.g Singapore              ."
    />
  </div>

  <button
    class="btn btn-lg btn-primary btn-block text-uppercase"
    routerLink="/houses"
    type="submit"
  >
    Find
  </button>
</form>