blocks|key|47904|text|这取决于您是想在之后与用户一起工作，还是只检查是否存在一个用户。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|47905|如果要使用user对象，请执行以下操作：|47906|$user+=+User::where('email',+'=',+Input::get('email'))->first();
if+($user+===+null)+{
+++//+user+doesn't+exist
}|code-block|syntax|javascript|47907|如果你只想检查|47908|if+(User::where('email',+'=',+Input::get('email'))->count()+>+0)+{
+++//+user+found
}|47909|或者甚至更好|47910|if+(User::where('email',+'=',+Input::get('email'))->exists())+{
+++//+user+found
}|47911|entityMap^0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|T|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|V|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|W|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|X|8|@]|9|@]|A|$]]|$1|O|3|P|5|F|7|Y|8|@]|9|@]|A|$G|H]]|$1|Q|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|R|$]]

It depends if you want to work with the user afterwards or only check if one exists.

If you want to use the user object if it exists:

<pre><code>$user = User::where('email', '=', Input::get('email'))-&gt;first();
if ($user === null) {
 // user doesn't exist
}
</code></pre>

And if you only want to check

<pre><code>if (User::where('email', '=', Input::get('email'))-&gt;count() &gt; 0) {
 // user found
}
</code></pre>

Or even nicer

<pre><code>if (User::where('email', '=', Input::get('email'))-&gt;exists()) {
 // user found
}
</code></pre>

blocks|key|48075|text|if+(User::where('email',+Input::get('email'))->exists())+{
++++//+exists
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|48076|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>if (User::where('email', Input::get('email'))-&gt;exists()) {
 // exists
}
</code></pre>

blocks|key|47920|text|最好的解决方案之一是使用firstOrNew或firstOrCreate方法。documentation在这两个方面都有更多的细节。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|47921|entityMap|0|LINK|mutability|MUTABLE|url|https://laravel.com/docs/5.7/eloquent#other-creation-methods^0|C|A|N|D|13|D|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@$9|O|A|P|B|C]|$9|Q|A|R|B|C]]|D|@$9|S|A|T|1|U]]|E|$]]|$1|F|3|-4|5|6|7|V|8|@]|D|@]|E|$]]]|G|$H|$5|I|J|K|E|$L|M]]]]

One of the best solution is to use the <code>firstOrNew</code> or <code>firstOrCreate</code> method. The <a href="https://laravel.com/docs/5.7/eloquent#other-creation-methods" rel="noreferrer">documentation</a> has more details on both.

blocks|key|4554564|text|if($user->isEmpty()){
++++//+has+no+records
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|4554565|Eloquent使用集合。请参阅以下链接：https://laravel.com/docs/5.4/eloquent-collections|unstyled|offset|length|4554566|entityMap|0|LINK|mutability|MUTABLE|url|https://laravel.com/docs/5.4/eloquent-collections^0|0|L|1D|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|R|8|@]|9|@$G|S|H|T|1|U]]|A|$]]|$1|I|3|-4|5|F|7|V|8|@]|9|@]|A|$]]]|J|$K|$5|L|M|N|A|$O|P]]]]

<pre><code>if($user-&gt;isEmpty()){
 // has no records
}
</code></pre>

Eloquent uses collections. 
See the following link: <a href="https://laravel.com/docs/5.4/eloquent-collections" rel="noreferrer">https://laravel.com/docs/5.4/eloquent-collections</a>

blocks|key|48495|text|在laravel+eloquent中，有默认的exists()方法，参考下面的例子。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|48496|if+(User::where('id',+$user_id+)->exists())+{
++++//+your+code...
}|code-block|syntax|javascript|48497|entityMap^0|N|8|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

In laravel eloquent, has default <code>exists()</code> method, refer followed example.
<pre><code>if (User::where('id', $user_id )-&gt;exists()) {
 // your code...
}
</code></pre>

blocks|key|48192|text|Laravel+5.6.26v|type|unstyled|depth|inlineStyleRanges|entityRanges|data|48193|通过主键(+email或id+)查找现有记录|48194|++++$user+=+DB::table('users')->where('email',$email)->first();|code-block|syntax|javascript|48195|然后|48196|++++++if(!$user){
+++++++++++++//user+is+not+found+
++++++}
++++++if($user){
+++++++++++++//+user+found+
++++++}|48197|包括“use+DB”和表名user使用上述查询如user+to+users变为复数|48198|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|T|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|U|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|V|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

Laravel 5.6.26v 

to find the existing record through primary key ( email or id ) 

<pre><code> $user = DB::table('users')-&gt;where('email',$email)-&gt;first();
</code></pre>

then 

<pre><code> if(!$user){
 //user is not found 
 }
 if($user){
 // user found 
 }
</code></pre>

include " use DB " and table name user become plural using the above query like user to users

blocks|key|48388|text|这将检查用户表中是否存在请求的电子邮件：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|48389|if+(User::where('email',+$request->email)->exists())+{
+++//email+exists+in+user+table
}|code-block|syntax|javascript|48390|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

This will check if requested email exist in the user table:

<pre><code>if (User::where('email', $request-&gt;email)-&gt;exists()) {
 //email exists in user table
}
</code></pre>

blocks|key|4555073|text|我用empty()函数解决了这个问题：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4555074|$user+=+User::where('email',+Input::get('email'))->get()->first();
//for+example:
if+(!empty($user))
++++User::destroy($user->id);|code-block|syntax|javascript|4555075|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I solved this, using empty() function:
<pre><code>$user = User::where('email', Input::get('email'))-&gt;get()-&gt;first();
//for example:
if (!empty($user))
 User::destroy($user-&gt;id);
</code></pre>

blocks|key|48129|text|检查if语句中的null可防止Laravel在查询结束后立即返回404。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|48130|if+(+User::find(+$userId+)+===+null+)+{

++++return+"user+does+not+exist";
}
else+{
++++$user+=+User::find(+$userId+);

++++return+$user;
}|code-block|syntax|javascript|48131|如果找到用户，它似乎会运行双重查询，但我似乎找不到任何其他可靠的解决方案。|48132|entityMap^0|2|2|8|4|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]|$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@]|D|@]|E|$]]|$1|M|3|-4|5|6|7|V|8|@]|D|@]|E|$]]]|N|$]]

Checking for <code>null</code> within <code>if</code> statement prevents Laravel from returning 404 immediately after the query is over.

<pre><code>if ( User::find( $userId ) === null ) {

 return "user does not exist";
}
else {
 $user = User::find( $userId );

 return $user;
}
</code></pre>

It seems like it runs double query if the user is found, but I can't seem to find any other reliable solution.

blocks|key|4554819|text|if+($u+=+User::where('email',+'=',+$value)->first())
{
+++//+do+something+with+$u
+++return+'exists';
}+else+{
++return+'nope';
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|4554820|将与try/catch一起工作|unstyled|4554821|->get()仍然会返回一个空数组|4554822|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|L|8|@]|9|@]|A|$]]|$1|G|3|H|5|F|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|F|7|N|8|@]|9|@]|A|$]]]|J|$]]

<pre><code>if ($u = User::where('email', '=', $value)-&gt;first())
{
 // do something with $u
 return 'exists';
} else {
 return 'nope';
}
</code></pre>

would work with try/catch 

->get() would still return an empty array

blocks|key|4554946|text|$email+=+User::find($request->email);
If($email->count()>0)
<h1>Email+exist,+please+make+new+email+address</h1>
endif|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|4554947|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>$email = User::find($request-&gt;email);
If($email-&gt;count()&gt;0)
&lt;h1&gt;Email exist, please make new email address&lt;/h1&gt;
endif
</code></pre>

blocks|key|48661|text|您已经看到了很多解决方案，但是神奇的语法检查可以像这样，|type|unstyled|depth|inlineStyleRanges|entityRanges|data|48662|$model+=+App\Flight::findOrFail(1);

$model+=+App\Flight::where('legs',+'>',+100)->firstOrFail();|code-block|syntax|javascript|48663|当找不到任何相关的模型时，它会自动抛出一个异常，响应404。有时，如果找不到模型，您可能希望抛出一个异常。这在路由或控制器中特别有用。Illuminate\Database\Eloquent\ModelNotFoundException和firstOrFail方法将检索查询的第一个结果；但是，如果没有找到任何结果，则将抛出一个指甲。|offset|length|style|CODE|48664|参考：https://laravel.com/docs/5.8/eloquent#retrieving-single-models|48665|entityMap|0|LINK|mutability|MUTABLE|url|https://laravel.com/docs/5.8/eloquent#retrieving-single-models^0|0|0|1V|1F|0|3|1Q|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Y|8|@$I|Z|J|10|K|L]]|9|@]|A|$]]|$1|M|3|N|5|6|7|11|8|@]|9|@$I|12|J|13|1|14]]|A|$]]|$1|O|3|-4|5|6|7|15|8|@]|9|@]|A|$]]]|P|$Q|$5|R|S|T|A|$U|V]]]]

you have seen plenty of solution, but magical checking syntax can be like,
<pre><code>$model = App\Flight::findOrFail(1);

$model = App\Flight::where('legs', '&gt;', 100)-&gt;firstOrFail();
</code></pre>
it will automatically raise an exception with response 404, when not found any related models Sometimes you may wish to throw an exception if a model is not found. This is particularly useful in routes or controllers. The fingernail and firstOrFail methods will retrieve the first result of the query; however, if no result is found, an <code>Illuminate\Database\Eloquent\ModelNotFoundException</code> will be thrown.
Ref: <a href="https://laravel.com/docs/5.8/eloquent#retrieving-single-models" rel="nofollow noreferrer">https://laravel.com/docs/5.8/eloquent#retrieving-single-models</a>

blocks|key|47992|text|$user+=+User::where('email',+request('email')->first();
return+(count($user)+>+0+?+'Email+Exist'+:+'Email+Not+Exist');|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|47993|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>$user = User::where('email', request('email')-&gt;first();
return (count($user) &gt; 0 ? 'Email Exist' : 'Email Not Exist');
</code></pre>

blocks|key|4554583|text|如果要插入唯一记录，可以使用laravel验证：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4554584|$validated+=+$request->validate([
++++'title'+=>+'required%7Cunique:usersTable,emailAddress%7Cmax:255',
]);|code-block|syntax|javascript|4554585|但是你也可以使用这些方法：|4554586|1：|4554587|if+(User::where('email',++$request->email)->exists())
{
++//+object+exists
}+else+{
++//+object+not+found
}|4554588|2：|4554589|$user+=+User::where('email',++$request->email)->first();

if+($user)
{
++//+object+exists
}+else+{
++//+object+not+found
}|4554590|3：|4554591|$user+=+User::where('email',++$request->email)->first();

if+($user->isNotEmpty())
{
++//+object+exists
}+else+{
++//+object+not+found
}|4554592|4：|4554593|$user+=+User::where('email',++$request->email)->firstOrCreate([
++++++'email'+=>+'email'
],$request->all());|4554594|entityMap^0|0|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|11|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|12|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|13|8|@]|9|@]|A|$]]|$1|K|3|L|5|D|7|14|8|@]|9|@]|A|$E|F]]|$1|M|3|N|5|6|7|15|8|@]|9|@]|A|$]]|$1|O|3|P|5|D|7|16|8|@]|9|@]|A|$E|F]]|$1|Q|3|R|5|6|7|17|8|@]|9|@]|A|$]]|$1|S|3|T|5|D|7|18|8|@]|9|@]|A|$E|F]]|$1|U|3|V|5|6|7|19|8|@]|9|@]|A|$]]|$1|W|3|X|5|D|7|1A|8|@]|9|@]|A|$E|F]]|$1|Y|3|-4|5|6|7|1B|8|@]|9|@]|A|$]]]|Z|$]]

You can use laravel validation if you want to insert a unique record:
<pre><code>$validated = $request-&gt;validate([
 'title' =&gt; 'required|unique:usersTable,emailAddress|max:255',
]);
</code></pre>
But also you can use these ways:
1:
<pre><code>if (User::where('email', $request-&gt;email)-&gt;exists())
{
 // object exists
} else {
 // object not found
}
</code></pre>
2:
<pre><code>$user = User::where('email', $request-&gt;email)-&gt;first();

if ($user)
{
 // object exists
} else {
 // object not found
}
</code></pre>
3:
<pre><code>$user = User::where('email', $request-&gt;email)-&gt;first();

if ($user-&gt;isNotEmpty())
{
 // object exists
} else {
 // object not found
}
</code></pre>
4:
<pre><code>$user = User::where('email', $request-&gt;email)-&gt;firstOrCreate([
 'email' =&gt; 'email'
],$request-&gt;all());
</code></pre>

blocks|key|4554636|text|这将检查表中是否存在特定的电子邮件地址：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4554637|if+(isset(User::where('email',+Input::get('email'))->value('email')))
{
++++//+Input::get('email')+exist+in+the+table+
}|code-block|syntax|javascript|4554638|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

This will check if particular email address exist in the table:

<pre><code>if (isset(User::where('email', Input::get('email'))-&gt;value('email')))
{
 // Input::get('email') exist in the table 
}
</code></pre>

blocks|key|48220|text|最短工作选项：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|48221|//+if+you+need+to+do+something+with+the+user+
if+($user+=+User::whereEmail(Input::get('email'))->first())+{

++++//+...

}

//+otherwise
$userExists+=+User::whereEmail(Input::get('email'))->exists();|code-block|syntax|javascript|48222|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Shortest working options:

<pre><code>// if you need to do something with the user 
if ($user = User::whereEmail(Input::get('email'))-&gt;first()) {

 // ...

}

// otherwise
$userExists = User::whereEmail(Input::get('email'))-&gt;exists();
</code></pre>

blocks|key|48264|text|$user+=+User::where('email',+'=',+Input::get('email'))->first();
if+($user+===+null)+{
+++//+user+doesn't+exist
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|48265|可以写成|unstyled|48266|if+(User::where('email',+'=',+Input::get('email'))->first()+===+null)+{
+++//+user+doesn't+exist
}|48267|这将返回true或false，而不赋值临时变量，如果这就是您在原始语句中使用$user的全部目的。|48268|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|N|8|@]|9|@]|A|$]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$B|C]]|$1|I|3|J|5|F|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|F|7|Q|8|@]|9|@]|A|$]]]|L|$]]

<pre><code>$user = User::where('email', '=', Input::get('email'))-&gt;first();
if ($user === null) {
 // user doesn't exist
}
</code></pre>

can be written as 

<pre><code>if (User::where('email', '=', Input::get('email'))-&gt;first() === null) {
 // user doesn't exist
}
</code></pre>

This will return true or false without assigning a temporary variable if that is all you are using $user for in the original statement.

blocks|key|4554842|text|我认为下面的方法是实现这一点的最简单的方法：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4554843|++++$user+=+User::where('email',+'=',+$request->input('email'))->first();
++++if+($user)+{
+++++++//+user+doesn't+exist!
++++}|code-block|syntax|javascript|4554844|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I think below way is the simplest way to achieving same :

<pre><code> $user = User::where('email', '=', $request-&gt;input('email'))-&gt;first();
 if ($user) {
 // user doesn't exist!
 }
</code></pre>

blocks|key|4554856|text|创建下面的方法(为我自己)，以检查给定的记录id是否存在于Db表中。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4554857|private+function+isModelRecordExist($model,+$recordId)
{
++++if+(!$recordId)+return+false;

++++$count+=+$model->where(['id'+=>+$recordId])->count();

++++return+$count+?+true+:+false;
}

//+To+Test
$recordId+=+5;
$status+=+$this->isModelRecordExist(+(new+MyTestModel()),+$recordId);|code-block|syntax|javascript|4554858|回家很有帮助！|4554859|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Created below method (for myself) to check if the given record id exists on Db table or not.

<pre><code>private function isModelRecordExist($model, $recordId)
{
 if (!$recordId) return false;

 $count = $model-&gt;where(['id' =&gt; $recordId])-&gt;count();

 return $count ? true : false;
}

// To Test
$recordId = 5;
$status = $this-&gt;isModelRecordExist( (new MyTestModel()), $recordId);
</code></pre>

Home It helps!

blocks|key|48511|text|最简单的方法是|type|unstyled|depth|inlineStyleRanges|entityRanges|data|48512|++++public+function+update(Request+$request,+$id)
{


++++$coupon+=+Coupon::where('name','=',$request->name)->first();+

++++if($coupon->id+!=+$id){
++++++++$validatedData+=+$request->validate([
++++++++++++'discount'+=>+'required',+++
++++++++++++'name'+=>+'required%7Cunique:coupons%7Cmax:255',++++++
++++++++]);
++++}


++++$requestData+=+$request->all();
++++$coupon+=+Coupon::findOrFail($id);
++++$coupon->update($requestData);
++++return+redirect('admin/coupons')->with('flash_message',+'Coupon+updated!');
}|code-block|syntax|javascript|48513|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

The Easiest Way to do 

<pre><code> public function update(Request $request, $id)
{


 $coupon = Coupon::where('name','=',$request-&gt;name)-&gt;first(); 

 if($coupon-&gt;id != $id){
 $validatedData = $request-&gt;validate([
 'discount' =&gt; 'required', 
 'name' =&gt; 'required|unique:coupons|max:255', 
 ]);
 }


 $requestData = $request-&gt;all();
 $coupon = Coupon::findOrFail($id);
 $coupon-&gt;update($requestData);
 return redirect('admin/coupons')-&gt;with('flash_message', 'Coupon updated!');
}
</code></pre>

blocks|key|48618|text|如果您想在数据库中插入一条记录，如果不存在具有相同电子邮件的记录，则可以执行以下操作：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|48619|$user+=+User::updateOrCreate(
++++['email'+=>+Input::get('email')],
++++['first_name'+=>+'Test',+'last_name'+=>+'Test']
);|code-block|syntax|javascript|48620|updateOrCreate方法的第一个参数列出了在关联表中唯一标识记录的列，而第二个参数由要插入或更新的值组成。|offset|length|style|CODE|48621|你可以在这里查看文档：Laravel+upserts+doc|48622|entityMap|0|LINK|mutability|MUTABLE|url|https://laravel.com/docs/8.x/eloquent#upserts^0|0|0|0|E|0|B|J|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Y|8|@$I|Z|J|10|K|L]]|9|@]|A|$]]|$1|M|3|N|5|6|7|11|8|@]|9|@$I|12|J|13|1|14]]|A|$]]|$1|O|3|-4|5|6|7|15|8|@]|9|@]|A|$]]]|P|$Q|$5|R|S|T|A|$U|V]]]]

If you want to insert a record in the database if a record with the same email not exists then you can do as follows:
<pre><code>$user = User::updateOrCreate(
 ['email' =&gt; Input::get('email')],
 ['first_name' =&gt; 'Test', 'last_name' =&gt; 'Test']
);
</code></pre>
The <code>updateOrCreate</code> method's first argument lists the column(s) that uniquely identify records within the associated table while the second argument consists of the values to insert or update.
You can check out the docs here: <a href="https://laravel.com/docs/8.x/eloquent#upserts" rel="nofollow noreferrer">Laravel upserts doc</a>

blocks|key|4555138|text|$userCnt+++++=+User::where("id",1)->count();
if(+$userCnt+==0+){
+++++//////////record+not+exists+
}else{
++++++//////////record+exists+
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|4555139|注意:：Where条件根据您的要求。|unstyled|4555140|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|J|8|@]|9|@]|A|$]]|$1|G|3|-4|5|F|7|K|8|@]|9|@]|A|$]]]|H|$]]

<pre><code>$userCnt = User::where(&quot;id&quot;,1)-&gt;count();
if( $userCnt ==0 ){
 //////////record not exists 
}else{
 //////////record exists 
}
</code></pre>
Note :: Where condition according your requirements.

blocks|key|48420|text|这是一个链接，指向l认为可以帮助https://laraveldaily.com/dont-check-record-exists-methods-orcreate-ornew/的东西|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|48421|entityMap|0|LINK|mutability|MUTABLE|url|https://laraveldaily.com/dont-check-record-exists-methods-orcreate-ornew/^0|G|21|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

here is a link to something l think can assist
<a href="https://laraveldaily.com/dont-check-record-exists-methods-orcreate-ornew/" rel="nofollow noreferrer">https://laraveldaily.com/dont-check-record-exists-methods-orcreate-ornew/</a>

blocks|key|48553|text|检查记录是否存在的有效方法必须使用is_null方法来检查查询。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|48554|下面的代码可能会有帮助：|48555|$user+=+User::where('email',+'=',+Input::get('email'));
if(is_null($user)){
+//user+does+not+exist...
}else{
+//user+exists...
}|code-block|syntax|javascript|48556|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

The efficient way to check if the record exists you must use is_null method to check against the query.

The code below might be helpful:

<pre><code>$user = User::where('email', '=', Input::get('email'));
if(is_null($user)){
 //user does not exist...
}else{
 //user exists...
}
</code></pre>

blocks|key|4554501|text|要知道是否有任何记录很简单|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4554502|$user+=+User::where('email',+'=',+Input::get('email'))->get();
if(count($user)+>+0)
{
echo+"There+is+data";
}
else
echo+"No+data";|code-block|syntax|javascript|4554503|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

It's simple to get to know if there are any records or not 

<pre><code>$user = User::where('email', '=', Input::get('email'))-&gt;get();
if(count($user) &gt; 0)
{
echo "There is data";
}
else
echo "No data";
</code></pre>

I am new to Laravel. Please excuse the newbie question but how do I find if a record exists?

<pre class="lang-php prettyprint-override"><code>$user = User::where('email', '=', Input::get('email'));
</code></pre>

What can I do here to see if <code>$user</code> has a record?

Laravel Checking If a Record Exists

数据库

路由

我是新来Laravel的。请原谅我的新手问题，但是我怎样才能发现记录是否存在？$user = User::where('email', '=', Input::get('email'));在这里我可以做些什么来查看$user是否有记录？

问Laravel检查记录是否存在
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