laravel 缓存 Eloquent 关系查询
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Cache Eloquent Relationship query
提问by FooBar
How can I cache this Eloquent query:
我如何缓存这个 Eloquent 查询：
dd($user->roles);
Because above will somehow trigger the $user->roles()query I assume.
因为上面会以某种方式触发$user->roles()我假设的查询。
I have tried with this:
我试过这个：
public function roles() {
return \Cache::remember('user_' . $this->id . '_roles', 10, function() {
return $this->hasMany('App\Role');
});
}
But it does not work, because it has to return a array, not eloquent query.
但它不起作用，因为它必须返回一个数组，而不是雄辩的查询。
Any suggestions?
有什么建议？
回答by Bogdan
You can't store a relationship in the cache. You need to cache the actual data retrieved from the database. So you'll have something like this:
您不能在缓存中存储关系。您需要缓存从数据库中检索到的实际数据。所以你会有这样的事情：
public function roles()
{
return \Cache::remember('user_' . $this->id . '_roles', 10, function()
{
return $this->hasMany('App\Role')->get()->toArray();
});
}
And now you have to access it as a method, not a property, because it's not returning a relation anymore (and Eloquent would throw an exception):
现在你必须将它作为方法而不是属性来访问，因为它不再返回关系（并且 Eloquent 会抛出异常）：
$user->roles();
Now you should get an array as you want.
现在你应该得到一个你想要的数组。
回答by MingalevME
Here is my approach:
这是我的方法：
public function bookmarks(): HasMany
{
return $this->hasMany(Bookmark::class);
}
protected function getBookmarksCacheKey(): string
{
return sprintf('user-%d-bookmarks', $this->id);
}
public function clearBookmarksCache(): bool
{
return Cache::forget($this->getBookmarksCacheKey());
}
public function getBookmarksAttribute(): Collection
{
if ($this->relationLoaded('bookmarks')) {
return $this->getRelationValue('bookmarks');
}
$bookmarks = Cache::rememberForever($this->getBookmarksCacheKey(), function () {
return $this->getRelationValue('bookmarks');
});
$this->setRelation('bookmarks', $bookmarks);
return $bookmarks;
}
回答by Marcin Nabia?ek
If you want to cache user together with its roles you can do it this way:
如果您想将用户与其角色一起缓存，您可以这样做：
$user = User::find(1);
$user->load('roles');
Cache::put('users_'.$user->id, $user, 10);
I don't know why, but you need to use loadhere instead of with. If you used withyou would get error that you cannot cache PDOinstance.
我不知道为什么，但你需要使用loadhere 而不是with. 如果你使用with你会得到你不能缓存PDO实例的错误。
