如何将 MySQL 查询转换为 Eloquent 关系？

Question

我真的不知道要搜索哪些词或术语。我还阅读了 laravel 5.7、https://laravel.com/docs/5.7/eloquent-relationships#many-to-many-polymorphic-relations.

中的文档

但是我还是找不到我想要的东西。

我期待的结果是MySQL:

SELECT id as product_id, (SELECT name FROM products WHERE id = transactions.product_id), created_at FROM transactions WHERE user_id = 1

这是 mysql 查询的结果：

我已经有一个模型：

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Transactions extends Model
{
    protected $table = 'transactions';
    protected $fillable = [
        'user_id', 'product_id'
    ];

    public function product()
    {
        return $this->hasOne('App\Products')->select('name');
    }
}
?>

然后在我的控制器中：

public function transactions()
{
    $transactions = new Transactions::where('user_id',Auth::id())->product;
    return view('transactions', ['transactions' => $transactions]);
}

Answer 1

你应该使用 belongsTo() 关系。交易属于一个产品，产品有多个交易。

此外，您可以（或者最好应该）将模型重命名为单数。那么你不需要使用 protected $table.

不一定要select只name.

交易模式：

namespace App;

use Illuminate\Database\Eloquent\Model;

class Transaction extends Model
{
    protected $fillable = ['user_id', 'product_id'];

    public function product()
    {
        return $this->belongsTo('App\Product');
    }
}

控制器：

public function transactions()
{
    $transactions = Transaction::with('product')
        ->where('user_id', Auth::id())
        ->get();

    return view('transactions', ['transactions' => $transactions]);
}

查看：

@foreach($transactions as $transaction)
    echo $transaction->product_id; //attribute product_id of transaction
    echo $transaction->product->id; //attribute id of product
    echo $transaction->product->name;  //attribute name of product
@endforeach

如何将 MySQL 查询转换为 Eloquent 关系？

How to convert MySQL query to Eloquent Relationships?

relationship

laravel-5.7