从响应而不是对象获取数组 [英] Get array from response instead of Object

问题描述

我试图仅从数据库中获取特定项目，然后将其显示在表中.

I am trying to get only specific items from my database then display it in table.

这是我的sql查询的样子

This is how my sql query looks like

public async aliasesListByDomain(req: Request, res: Response): Promise<void> {
    const { domain } = req.params;
    const aliases = await pool.query('SELECT * FROM virtual_aliases INNER JOIN virtual_domains ON virtual_aliases.domain_id = virtual_domains.id WHERE virtual_aliases.domain_id = ?', [domain]);
    if (aliases.length > 0) {
        res.json(aliases);
    } else {
        res.status(404).json({ message: "Alias doesn't exists" });
    }
}

有我的Aliases.service

There is my Aliases.service

 getAliasesByDomain(domain: string): Observable<Alias> {
    return this.http.get(`${this.API_URI}/aliases/aliaseslistbydomain/${domain}`);
  }

这是我的组成部分

 getAliasesByDomain() {
    const token = this.getToken();
    let user;
    let domain;
    console.log(token);
    if(token){
      user = token.split('.')[1];
      user = window.atob(user);
      user = JSON.parse(user);
      domain = user.domain;

    }
    this.aliasesService.getAliasesByDomain(domain).subscribe(
      res => {
        this.alias = res;
      },
      err => console.error(err)
    );
  }

和组件html

<tr *ngFor="let aliases of alias;">

我的问题是我得到了错误:

My problem is that I got error:

AliasesListComponent.html:17错误错误:找不到其他支持对象的别名:输入字符串".NgFor仅支持绑定到Iterables，例如数组.

AliasesListComponent.html:17 ERROR Error: Cannot find a differ supporting object 'to sa aliases: [object Object],[object Object]' of type 'string'. NgFor only supports binding to Iterables such as Arrays.

因为我的响应是Object对象而不是array.我该如何解析?

Because my response is Object object instead of array. How can I parse this?

推荐答案

如果您的回调函数为您提供了一个数组，您可以像这样在服务内部指定它

If your callback gives you an array you can just specify it inside the service like this

 getAliasesByDomain(domain: string): Observable<Alias[]> {
    return this.http.get<Alias[]>(`${this.API_URI}/aliases/aliaseslistbydomain/${domain}`);
  }

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