Laravel渴望加载，多个相同具有一个关系 [英] Laravel Eager Loading, multiple same hasOne relations

问题描述

我有2个简单的模型.首先，一个叫做Builds，第二个叫做SlotOptions.每个版本都可以分配5个插槽.

I have 2 simple models. First, one is called Builds and the second one is called SlotOptions. Each build can have like 5 assigned slots.

class BuildDB extends Model

并且有5个这样的关系slot1-5 and id changes to slot1-5_id

And has 5 such relations slot1-5 and id changes to slot1-5_id

 public function slot1()
    {
        return $this->hasOne('\App\SlotOptions', 'id', 'slot1_id');
    }

在控制器中我这样称呼；

In the controller I call it such way;

BuildDB::with([ 'slot1', 'slot2', 'slot3', 'slot4', 'slot5'])->find(5);

\App\SlotOptions模型不包含任何额外的编码.

\App\SlotOptions model doesn't contain any extra coding.

这将生成5个相同"查询. -atm急切的加载将在我获得构建列表的情况下起作用，并且每个插槽都具有whereIn子句，是否可以将其作为一个大的wherein子句，或者是否需要更改数据库架构.

This generates 5 "same" queries. - atm the eager loading would work if I get a list of builds and each slot would have whereIn clause, is it possible to have it a one big wherein the clause, or does it require to change the DB schema.

推荐答案

在这种情况下，无法优化紧急加载.

It's not possible to optimize eager loading in this case.

我建议您将数据库架构更改为多对-许多关系.
这种设计更加灵活，可以让您将来轻松添加更多插槽.

I recommend that you change your database schema to a many-to-many relationship.
This design is more flexible, it allows you to easily add more slots in the future.

使用以下列创建名为build_slot_option的数据透视表:build_id，slot_option_id
如果要对插槽进行编号/排序，请添加一列.

Create a pivot table named build_slot_option with these columns: build_id, slot_option_id
Add an additional column if you want to number/order the slots.

然后定义 BelongsToMany 关系:

Then define a BelongsToMany relationship:

class BuildDB extends Model
{
    public function slots()
    {
        return $this->belongsToMany(
            SlotOptions::class, 'build_slot_option', 'build_id', 'slot_option_id'
        );
    }
}

BuildDB::with('slots')->find(5);

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