Laravel Eager Loading - 仅加载特定列

Laravel Eager Loading - Load only specific columns(Laravel Eager Loading - 仅加载特定列)

问题描述

我正在尝试在 laravel 中急切加载模型，但只返回某些列.我不希望呈现整个急切加载的表格.

I am trying to eager load a model in laravel but only return certain columns. I do not want the whole eager loaded table being presented.

public function car()
{
    return $this->hasOne('Car', 'id')->get(['emailid','name']);
}

我收到以下错误:

log.ERROR: 异常 'SymfonyComponentDebugExceptionFatalErrorException' 带有消息 'Call to undefined method IlluminateDatabaseEloquentCollection::getAndResetWheres()'

log.ERROR: exception 'SymfonyComponentDebugExceptionFatalErrorException' with message 'Call to undefined method IlluminateDatabaseEloquentCollection::getAndResetWheres()'

推荐答案

利用select()方法:

public function car() {
    return $this->hasOne('Car', 'id')->select(['owner_id', 'emailid', 'name']);
}

注意:记得添加分配给匹配两个表的外键的列.例如，在我的示例中，我假设 Owner 有一个 Car，这意味着分配给外键的列类似于 owners.id = cars.owner_id，所以我必须将 owner_id 添加到所选列的列表中；

Note: Remember to add the columns assigned to the foreign key matching both tables. For instance, in my example, I assumed a Owner has a Car, meaning that the columns assigned to the foreign key would be something like owners.id = cars.owner_id, so I had to add owner_id to the list of selected columns;

这篇关于Laravel Eager Loading - 仅加载特定列的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持编程学习网！