Laravel 模型使用软删除-左连接查询-表起别名示例

来源：jb51　　时间：2019/10/24 10:50:44　　对本文有异议

事情是这样的，有天写了一个左连接查询，由于表名太长，所以分别给起个别名，代码如下：

public function detail()
{
  $result = TakeOrderModel::query()
    ->from('take_order as order')
    ->leftJoin('take_order_detail as detail', 'order.id', '=', 'detail.take_order_id')
    ->get();
  dd($result);
}

执行后，报错 Column not found: 1054 Unknown column take_order.delete_time。

查看解决办法的，直接看底部

SQL:

select * from take_order as order
left join take_order_detail as detail
on order.take_order_id = detail.take_order_id
where take_order.delete_time is null

显而易见：软删除查询条件的表名是全名，所以报错了。

分析

软删除作用域 SoftDeletingScope 源码：

/**
 * Apply the scope to a given Eloquent query builder.
 *
 * @param \Illuminate\Database\Eloquent\Builder $builder
 * @param \Illuminate\Database\Eloquent\Model $model
 * @return void
 */
public function apply(Builder $builder, Model $model)
{
  $builder->whereNull($model->getQualifiedDeletedAtColumn());
}

查看 getQualifiedDeletedAtColumn 源码：

/**
 * Get the fully qualified "deleted at" column.
 *
 * @return string
 */
public function getQualifiedDeletedAtColumn()
{
  return $this->qualifyColumn($this->getDeletedAtColumn());
}

查看 qualifyColumn 源码：

/**
 * Qualify the given column name by the model's table.
 *
 * @param string $column
 * @return string
 */
public function qualifyColumn($column)
{
  return $this->model->qualifyColumn($column);
}

查看 qualifyColumn 源码：

/**
 * Qualify the given column name by the model's table.
 *
 * @param string $column
 * @return string
 */
public function qualifyColumn($column)
{
  if (Str::contains($column, '.')) {
    return $column;
  }
 
  return $this->getTable().'.'.$column;
}

以上可知： $this->getTable().'.'.$column 即为软删除条件的字段名。

解决办法

代码改成下面这样，加一行 setTable 设置表名，就可以了。

$result = (new TakeOrderModel())
    ->setTable('order')
    ->from('take_order as order')
    ->leftJoin('take_order_detail as detail', 'order.take_order_id', '=', 'detail.take_order_id')
    ->get();