Laravel Eloquent : 统计两个表的数据

Question

我有两个不同的 table，名为 artists 和 artworks。我想从 table 中检索数据并在 Summary table 中显示它们。

这里的条件是：从artiststable得到name（这个table还有其他列）和从 artworks table 得到 number of total artworks。在 Summary table.

中显示它们

artists
|-------------------|
|  id   |   name    |
|-------------------|
|  1    |    A      |
|-------------------|
|  2    |    B      |
|-------------------|
|  3    |    C      |
|-------------------|

artworks
|-----------------------------------------------------|
|  id   |   artist_id   |   title   |     medium      |
|-----------------------------------------------------|
|  1    |       1       |    ABC    |      Oil        |
|-----------------------------------------------------|
|  2    |       1       |    DEF    |     Water       |
|-----------------------------------------------------|
|  3    |       1       |    GHI    |     Water       |
|-----------------------------------------------------|
|  1    |       2       |    JKL    |      Oil        |
|-----------------------------------------------------|
|  2    |       2       |    MNO    |     Water       |
|-----------------------------------------------------|
|  3    |       3       |    PQR    |      Oil        |
|-----------------------------------------------------|

这就是我想要的：

Summary
|-------------------------------------------|
|  No   |   Artist Name  |   Total Artwork  |
|-------------------------------------------|
|  1    |        A       |         3        |
|-------------------------------------------|
|  2    |        B       |         2        |
|-------------------------------------------|
|  3    |        C       |         1        |
|-------------------------------------------|

我们将不胜感激任何帮助。感谢您的宝贵时间。

Answer 1

您可以对您的关系使用withCount()方法：

$artists = Artist::withCount('artworks')->get();
foreach($artists as $artist) {
    echo $artist->artworks_count;
}

Answer 2

因为你想使用数据库查询，所以你需要添加连接。

\DB::table('artists')
->join('artworks', 'artists.id', '=', 'artworks.artist_id')
->select('artists.id as id', 'artists.name as name', \DB::raw("count(artworks.artist_id) as count"))
->groupBy('artists.id')
->get();

如果您想使用 Relation，则在 Artist 模型中使用 hasMany 关系。

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Artist extends Model
{
    protected $table = 'artists';

    public function artworks()
    {
        return $this->hasMany('App\Artwork','artist_id','id');
    }
}

在控制器中

$artists = Artist::withCount('artworks')->get();
foreach($artists as $artist) {
    echo $artist->artworks_count;
}

Laravel Eloquent : 统计两个表的数据

Laravel Eloquent : Count data from two tables

mysql

laravel

eloquent

laravel-5.7