Laravel Pivot Relationship not unique table/alias - laravel

Question

I have three Tables & corresponding models:
Table ------ Model
papers ------ Paper
paper_stocks ------ PaperStock
paper_stock_amounts ------ PaperStockAmount
Paper contains diff. types of paper.
PaperStock contains different places where these papers can be stored
PaperStockAmount contains the paper id, the stock id and the amount, to determine how many of paper A are in stock B.
Now I want to check outgoing from the paper how manyy are in each stock. Therefore Im doing this in my view:
#foreach($papers as $paper)
#foreach($paper->paperStockAmount as $ps)
<tr>
<td>{{ $ps->stock->name }}</td>
<td>{{ $ps->amount }}</td>
</tr>
#endforeach
#endforeach
This should show every type of paper and in which stocks along with the amount they are in.
However this is the error:
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))
The relationships are defined like this:
Paper
class Paper extends Model
{
public function paperStockAmount()
{
return $this->belongsToMany('App\PaperStockAmount', 'paper_stock_amounts')->withPivot('amount');
}
}
PaperStockAmount
class PaperStockAmount extends Model
{
public function paper()
{
return $this->hasOne('App\Paper', 'id', 'paper_id');
}
public function stock()
{
return $this->hasOne('App\PaperStock', 'id', 'stock_id');
}
}
Why doesn't this work?

Answer 1

You've defined M-M Relationship between paper & paper_stock.
i.e. If you are fetching paperStockAmount from $paper, then you would get paper_stock results with the pivot column amount.
You should do it like this:
#foreach($papers as $paper)
#foreach($paper->paperStockAmount as $paper_stock)
<tr>
<td>{{ $paper_stock->name }}</td>
<td>{{ $paper_stock->pivot->amount }}</td>
</tr>
#endforeach
#endforeach
Use pivot to fetch the pivot column named - amount
Hope this helps!

Answer 2

I am not sure but it looks your relation from Paper to PaperStockAmount is has-many, so your relation should be as:
Paper
class Paper extends Model
{
public function paperStockAmount()
{
return $this->belongsToMany('App\PaperStockAmount');
}
}
Then your view code will work.
OR
If the relation between from Paper and PaperStock is many-to-many then your relation should be as:
Paper
class Paper extends Model
{
public function paperStockAmount()
{
return $this->hasMany('App\PaperStock', 'paper_stock_amounts')->withPivot('amount');
}
}
Then in your view, it can be accessed as: (taking from #saumya answer)
#foreach($papers as $paper)
#foreach($paper->paperStockAmount as $paper_stock)
<tr>
<td>{{ $paper_stock->name }}</td>
<td>{{ $paper_stock->pivot->amount }}</td>
</tr>
#endforeach
#endforeach