Laravel:创建或更新相关模型? [英] Laravel: Create or update related model?

问题描述

请对我温柔-我是Laravel菜鸟.

Please be gentle with me - I'm a Laravel noob.

因此，目前，我遍历大量用户，以确定是否需要更新相关模型(UserLocation).

So currently, I loop through a load of users deciding whether I need to update a related model (UserLocation).

如果需要创建UserLocation，我已经尽其所能，经过一番摸索之后，我提出了以下建议；

I've got as far as creating a UserLocation if it needs creating, and after a bit of fumbling, I've come up with the following;

$coords = $json->features[0]->geometry->coordinates;  
$location = new UserLocation(['lat'=>$coords[1],'lng'=>$coords[0]]);  
$user->location()->save($location);  

我的问题是第二次，该位置可能需要更新，并且该用户已经存在一行.

My issue is that one the second time around, the Location may want updating and a row will already exist for that user.

这是自动处理的吗，还是我需要做一些不同的事情?

Is this handled automatically, or do I need to do something different?

代码读起来就像是在创建新行一样，所以不能处理需要更新的情况吗?

The code reads like it's creating a new row, so wouldn't handle the case of needing to update it?

更新-解决方案:

感谢马修，我想出了以下解决方案；

Thanks to Matthew, I've come up with the following solution;

$location = UserLocation::firstOrNew(['user_id'=>$user->id]);
$location->user_id = $user->id;
$location->lat = $coords[1];
$location->lng = $coords[0];
$location->save();

推荐答案

您应参考 Laravel API文档.我认为他们没有在常规文档"中提及这些方法，因此我理解为什么您可能没有看到它.

You should reference the Laravel API Docs. I don't think they mention these methods in the "regular docs" though so I understand why you may have not seen it.

您可以使用模型firstOrNew或firstOrCreate的方法.

You can use the models firstOrNew or firstOrCreate methods.

firstOrNew::获取匹配属性的第一条记录或实例化 它.

firstOrNew: Get the first record matching the attributes or instantiate it.

firstOrCreate::获取匹配属性的第一条记录或创建它.

firstOrCreate: Get the first record matching the attributes or create it.

例如:

$model = SomeModel::firstOrNew(['model_id' => 4]);

在上面的示例中，如果未找到model_id为4的模型，则它将创建SomeModel的新实例.然后可以进行操作，以后再按->save().如果找到，则将其返回.

In the above example, if a model with a model_id of 4 isn't found then it creates a new instance of SomeModel. Which you can then manipulate and later ->save(). If it is found, it is returned.

您还可以使用firstOrCreate，它不会创建新的Model实例，而是立即将新模型插入表中.

You can also use firstOrCreate, which instead of creating a new Model instance would insert the new model into the table immediately.

所以在您的情况下:

$location = UserLocation::firstOrNew(['lat'=>$coords[1],'lng'=>$coords[0]]);

$ location将包含数据库中的现有模型，或者包含属性分别为lat和lng分别设置为$coords[1]和$coords[0]的新实例，然后可以保存或设置更多属性值需要.

$location will either contain the existing model from the DB or a new instance with the attributes lat and lng set to $coords[1] and $coords[0] respectively, which you can then save or set more attribute values if needed.

另一个例子:

$location = UserLocation::firstOrCreate(['lat'=>$coords[1],'lng'=>$coords[0]]);

$ location将包含数据库中的现有模型或具有已设置属性的新模型，除非这次没有找到该模型.

$location will either contain the existing model from the DB or a new model with the attributes set again, except this time the model will have already been written to the table if not found.

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