这是一个简单的代码来检查电子邮件是否存在数据库

    $data = $request->all();
    $user = DB::table('User')->pluck('email')->toArray();
    if(in_array($user,$data['email']))
    {
    echo 'existed email';
    }

这是一个简单的代码来检查电子邮件是否存在数据库

    $data = $request->all();
    $user = DB::table('User')->pluck('email')->toArray();
    if(in_array($user,$data['email']))
    {
    echo 'existed email';
    }

这将检查表中是否存在特定的电子邮件地址:

if (isset(User::where('email', Input::get('email'))->value('email')))
{
    // Input::get('email') exist in the table 
}

如果你想插入一个唯一的记录，你可以使用laravel验证:

$validated = $request->validate([
    'title' => 'required|unique:usersTable,emailAddress|max:255',
]);

但是你也可以用这些方法:

1:

if (User::where('email',  $request->email)->exists())
{
  // object exists
} else {
  // object not found
}

2:

$user = User::where('email',  $request->email)->first();

if ($user)
{
  // object exists
} else {
  // object not found
}

3:

$user = User::where('email',  $request->email)->first();

if ($user->isNotEmpty())
{
  // object exists
} else {
  // object not found
}

4:

$user = User::where('email',  $request->email)->firstOrCreate([
      'email' => 'email'
],$request->all());

$user = User::where('email', request('email'))->first();
return (count($user) > 0 ? 'Email Exist' : 'Email Not Exist');

这将检查用户表中是否存在所请求的电子邮件:

if (User::where('email', $request->email)->exists()) {
   //email exists in user table
}