laravel query if exists code example

Example 1: limit laravel

$posts = Post::all()->limit(10)->get();

Example 2: laravel check record exists

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

Example 3: laravel not in query

DB::table(..)->select(..)->whereNotIn('book_price', [100,200])->get();

Example 4: if notexists in laravel query

if (User::where('email', '=', Input::get('email'))->exists()) {
   // user found
}