php Eloquent ->first() 如果 ->exists()
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Eloquent ->first() if ->exists()
提问by Webinan
I want to get the first row in table where condition matches:
我想获取条件匹配的表中的第一行：
User::where('mobile', Input::get('mobile'))->first()
It works well, but if the condition doesn't match, it throws an Exception:
它运行良好，但如果条件不匹配，则会抛出异常：
ErrorException
Trying to get property of non-object
Currently I resolve it like this:
目前我是这样解决的：
if (User::where('mobile', Input::get('mobile'))->exists()) {
$user = User::where('mobile', Input::get('mobile'))->first()
}
Can I do this without running two queries?
我可以在不运行两个查询的情况下执行此操作吗？
回答by Matt Burrow
Note: The first() method doesn't throw an exception as described in the original question. If you're getting this kind of exception, there is another error in your code.
注意： first() 方法不会像原始问题中描述的那样抛出异常。如果您收到此类异常，则您的代码中存在另一个错误。
The correct way to user first() and check for a result:
使用 first() 并检查结果的正确方法：
$user = User::where('mobile', Input::get('mobile'))->first(); // model or null
if (!$user) {
// Do stuff if it doesn't exist.
}
Other techniques (not recommended, unnecessary overhead):
其他技术（不推荐，不必要的开销）：
$user = User::where('mobile', Input::get('mobile'))->get();
if (!$user->isEmpty()){
$firstUser = $user->first()
}
or
或者
try {
$user = User::where('mobile', Input::get('mobile'))->firstOrFail();
// Do stuff when user exists.
} catch (ErrorException $e) {
// Do stuff if it doesn't exist.
}
or
或者
// Use either one of the below.
$users = User::where('mobile', Input::get('mobile'))->get(); //Collection
if (count($users)){
// Use the collection, to get the first item use $users->first().
// Use the model if you used ->first();
}
Each one is a different way to get your required result.
每一种都是获得所需结果的不同方式。
回答by ash
(ps - I couldn't comment) I think your best bet is something like you've done, or similar to:
（ps - 我无法发表评论）我认为你最好的选择是你做过的事情，或者类似于：
$user = User::where('mobile', Input::get('mobile'));
$user->exists() and $user = $user->first();
Oh, also: count()instead if existsbut this could be something used after get.
哦，还有：count()如果exists但这可以在get.
回答by Jarek Tkaczyk
getreturns Collectionand is rather supposed to fetch multiple rows.
get返回Collection并且应该获取多行。
countis a generic way of checking the result:
count是检查结果的通用方法：
$user = User::where(...)->first(); // returns Model or null
if (count($user)) // do what you want with $user
// or use this:
$user = User::where(...)->firstOrFail(); // returns Model or throws ModelNotFoundException
// count will works with a collection of course:
$users = User::where(...)->get(); // returns Collection always (might be empty)
if (count($users)) // do what you want with $users
回答by Rashi Goyal
Try it this way in a simple manner it will work
以一种简单的方式尝试这种方式它会起作用
$userset = User::where('name',$data['name'])->first();
if(!$userset) echo "no user found";
回答by user1669496
An answer has already been accepted, but in these situations, a more elegant solution in my opinion would be to use error handling.
一个答案已经被接受，但在这些情况下，我认为更优雅的解决方案是使用错误处理。
try {
$user = User::where('mobile', Input::get('mobile'))->first();
} catch (ErrorException $e) {
// Do stuff here that you need to do if it doesn't exist.
return View::make('some.view')->with('msg', $e->getMessage());
}
