Question

我有三张桌子和一张桌子。相应的型号：

表 ------ 型号

论文------论文

paper_stocks ------ PaperStock

paper_stock_amounts ------ PaperStockAmount

纸张包含差异。纸张类型。 PaperStock包含可存放这些纸张的不同位置 PaperStockAmount包含纸张ID，库存ID和数量，以确定纸张B中有多少纸张。

现在我想检查一下纸上传出的每个库存中有多少。因此我在我看来这样做：

DELETE FROM TestTranslationTable WHERE ID IN(
     SELECT Id FROM TestTranslationTable tblMain
     WHERE tblMain.Id NOT IN (SELECT TOP 1 tblNested.id FROM TestTranslationTable tblNested WHERE 
     tblNested.TranslationConnectionId=tblMain.TranslationConnectionId ORDER BY tblNested.TranslationConnectionId)
     AND tblMain.TranslationConnectionId IN(SELECT TranslationConnectionId FROM TestTranslationTable 
     GROUP BY TranslationConnectionId HAVING COUNT(TranslationConnectionId)>1 )
     )
     GO

这应该显示每种类型的纸张以及哪些库存以及它们的数量。

然而这是错误：

@foreach($papers as $paper)
    @foreach($paper->paperStockAmount as $ps)
        <tr>
            <td>{{ $ps->stock->name }}</td>
            <td>{{ $ps->amount }}</td>
        </tr>
    @endforeach
@endforeach

关系定义如下：

纸张

SQLSTATE[42000]: Syntax error or access violation: 1066 Not unique table/alias: 'paper_stock_amounts' (SQL: select `paper_stock_amounts`.*, `paper_stock_amounts`.`id` as `pivot_id`, `paper_stock_amounts`.`amount` as `pivot_amount` from `paper_stock_amounts` inner join `paper_stock_amounts` on `paper_stock_amounts`.`id` = `paper_stock_amounts`.`id` where `paper_stock_amounts`.`id` in (1, 2))

PaperStockAmount

class Paper extends Model
{
    public function paperStockAmount()
    {
        return $this->belongsToMany('App\PaperStockAmount', 'paper_stock_amounts')->withPivot('amount');
    }
}

为什么这不起作用？

Answer 1

您已定义paper＆amp;之间的M-M关系paper_stock。

即。如果您从paperStockAmount获取$paper，那么您将获得paper_stock个结果列amount的结果。

你应该这样做：

@foreach($papers as $paper)
    @foreach($paper->paperStockAmount as $paper_stock)
        <tr>
            <td>{{ $paper_stock->name }}</td>
            <td>{{ $paper_stock->pivot->amount }}</td>
        </tr>
    @endforeach
@endforeach

使用pivot获取名为 - amount

的数据透视表列

希望这有帮助！

Answer 2

我不确定但看起来您Paper到PaperStockAmount的关系是has-many，所以您的关系应该是：

纸张

class Paper extends Model
{
    public function paperStockAmount()
    {
        return $this->belongsToMany('App\PaperStockAmount');
    }
}

然后您的视图代码将起作用。

OR

如果Paper和PaperStock之间的关系为many-to-many，则您的关系应为：

纸张

class Paper extends Model
{
    public function paperStockAmount()
    {
        return $this->hasMany('App\PaperStock', 'paper_stock_amounts')->withPivot('amount');
    }
}

然后在您看来，它可以被访问为:(从@saumya回答）

@foreach($papers as $paper)
    @foreach($paper->paperStockAmount as $paper_stock)
        <tr>
            <td>{{ $paper_stock->name }}</td>
            <td>{{ $paper_stock->pivot->amount }}</td>
        </tr>
    @endforeach
@endforeach

Laravel Pivot关系不是唯一的表/别名

2 个答案: