php 如何使用 Laravel Eloquent 返回多个关系？

How to return multiple relationships with Laravel Eloquent?

提问by Radical_Activity

I have a table called users. Each of these users has different things:

我有一张桌子叫users. 这些用户中的每一个都有不同的东西：

• country
• device
• computer
• category

• 国家
• 设备
• 计算机
• 类别

I have created a table for each of these above 'things'. Similar the following:

我为上述“事物”中的每一个都创建了一个表格。类似如下：

1 | United States
2 | United Kingdom
3 | Australia
4 | Canada
5 | Italy

etc...

等等...

I'm storing these values in the users table as follows:

我将这些值存储在用户表中，如下所示：

ID | Country | Device | Computer | Category |
---|---------|--------|----------|----------|
1  |       3 |      2 |        6 |        2 |
2  |       4 |      3 |        9 |        1 |

etc...

等等...

Now each of the above numbers are associated with the corresponding table's ID.

现在上面的每个数字都与相应的表的 ID 相关联。

What I want is do an Eloquent Query and search for all the usersand 'replacing' their corresponding values from their helper table.

我想要的是做一个 Eloquent Query 并users从他们的帮助表中搜索所有和“替换”他们相应的值。

I was thinking about doing a hasOne()Eloquent relationship for each of those things in the userstable, but then I'm not sure how to get/call them at once.

我正在考虑hasOne()为users表格中的每一项建立Eloquent 关系，但是我不确定如何立即获取/调用它们。

Anyone can help me tacke this issue?

任何人都可以帮我解决这个问题吗？

回答by Andrew Nolan

$model = Model::with('relatedModel', 'relatedModelTwo')->get();

So in your case, it can be something like this. If you only want one relations returned with the user, remove the others.

所以在你的情况下，它可能是这样的。如果您只想用 返回一个关系user，请删除其他关系。

$user = User::with('country', 'Device', 'Computer', 'Category')->get();

When you dd($user), you should see the related models in the relationsarray attribute.

当你dd($user)，你应该在relations数组属性中看到相关的模型。

To access the relations' properties from there, it is simply

要从那里访问关系的属性，只需

$user->device->deviceAttribute

$user->device->deviceAttribute

Edit For Comment:

编辑评论：

Eloquent will assume the foreign key uses the Model name. So if your usertable has the idcolumn, it assumes there will be a column on devicetable called user_id. If you did this, then you are set and nothing should have to be done.

Eloquent 将假定外键使用模型名称。因此，如果您的user表有该id列，则假定device表上将有一列名为user_id. 如果你这样做了，那么你就准备好了，什么都不用做。

If you named your column to relate the models something else, you will need to pass that through as a second argument in the relation method.

如果您将列命名为与模型相关联，则需要将其作为关系方法中的第二个参数传递。

public function device()
{
    return $this->hasOne('App\Device', 'foreign_key_here',);
}

Inversely, if you wanted to get the user the device belongs to, Eloquent will attempt to match the user_idcolumn on the device table to the idcolumn on the user table. As before, if you used a different column to related them, declare the foreign key as the second argument.

相反，如果您想获取设备所属的用户，Eloquent 会尝试user_id将设备表中的id列与用户表中的列进行匹配。和以前一样，如果您使用不同的列来关联它们，请将外键声明为第二个参数。

public function user()
{
    return $this->belongsTo('App\User', 'foreign_key_here',);
}

Laravel Doc One-To-One Relation

Laravel Doc 一对一关系

回答by Daniel

You're looking for this: $books = App\Book::with('author', 'publisher')->get();

你正在寻找这个： $books = App\Book::with('author', 'publisher')->get();

Check out the documentation for eager loading multiple relationships.

查看文档以了解预先加载多个关系。