Laravel Query Builder: CRUD Operations, Advanced Queries, and Performance Tips

The following guide demonstrates how to use Laravel's query builder to perform common database operations and more advanced queries.

Selects

$users = DB::table('users')->get();
foreach ($users as $user) {
    var_dump($user->name);
}

$user = DB::table('users')->where('name', 'John')->first();
var_dump($user->name);

$name = DB::table('users')->where('name', 'John')->pluck('name');

$roles = DB::table('roles')->lists('title');
$roles = DB::table('roles')->lists('title', 'name');

$users = DB::table('users')->select('name', 'email')->get();
$users = DB::table('users')->distinct()->get();
$users = DB::table('users')->select('name as user_name')->get();

Adding Selects to an Existing Query

$query = DB::table('users')->select('name');
$users = $query->addSelect('age')->get();
var_dump($users);

Where Clauses

$users = DB::table('users')->where('votes', '>', 100)->get();

$users = DB::table('users')->where('votes', '>', 100)->orWhere('name', 'John')->get();

$users = DB::table('users')->whereBetween('votes', array(1, 100))->get();

$users = DB::table('users')->whereNotBetween('votes', array(1, 100))->get();

$users = DB::table('users')->whereIn('id', array(1,2,3))->get();
$users = DB::table('users')->whereNotIn('id', array(1,2,3))->get();

$users = DB::table('users')->whereNull('updated_at')->get();

Order, Group, and Having

$users = DB::table('users')
    ->orderBy('name', 'desc')
    ->groupBy('count')
    ->having('count', '>', 100)
    ->get();

Offset & Limit

$users = DB::table('users')->skip(10)->take(5)->get();

Joins

DB::table('users')
    ->join('contacts', 'users.id', '=', 'contacts.user_id')
    ->join('orders', 'users.id', '=', 'orders.user_id')
    ->select('users.id', 'contacts.phone', 'orders.price')
    ->get();

DB::table('users')->leftJoin('posts', 'users.id', '=', 'posts.user_id')->get();

DB::table('users')->join('contacts', function($join) {
    $join->on('users.id', '=', 'contacts.user_id')
         ->orOn(...);
})->get();

Nested Where Clauses

DB::table('users')
    ->where('name', '=', 'John')
    ->orWhere(function($query) {
        $query->where('votes', '>', 100)
              ->where('title', '<>', 'Admin');
    })
    ->get();

Aggregates

$count = DB::table('users')->count();
$maxPrice = DB::table('orders')->max('price');
$minPrice = DB::table('orders')->min('price');
$avgPrice = DB::table('orders')->avg('price');
$totalVotes = DB::table('users')->sum('votes');

Raw Expressions

$users = DB::table('users')
    ->select(DB::raw('count(*) as user_count, status'))
    ->where('status', '<>', 1)
    ->groupBy('status')
    ->get();

Increment / Decrement

DB::table('users')->increment('votes');
DB::table('users')->increment('votes', 5);
DB::table('users')->decrement('votes');
DB::table('users')->decrement('votes', 5);
DB::table('users')->increment('votes', 1, ['name' => 'John']);

Inserts

DB::table('users')->insert(['email' => '[email protected]', 'votes' => 0]);

$id = DB::table('users')->insertGetId(['email' => '[email protected]', 'votes' => 0]);

DB::table('users')->insert([
    ['email' => '[email protected]', 'votes' => 0],
    ['email' => '[email protected]', 'votes' => 0]
]);

Updates

DB::table('users')->where('id', 1)->update(['votes' => 1]);

Deletes

DB::table('users')->where('votes', '<', 100)->delete();
DB::table('users')->delete();
DB::table('users')->truncate();

Unions

$first = DB::table('users')->whereNull('first_name');
$users = DB::table('users')->whereNull('last_name')->union($first)->get();

Locking

DB::table('users')->where('votes', '>', 100)->sharedLock()->get();
DB::table('users')->where('votes', '>', 100)->lockForUpdate()->get();

Caching Queries

$users = DB::table('users')->remember(10)->get();
$users = DB::table('users')->cacheTags(['people','authors'])->remember(10)->get();

The article concludes with a brief motivational note and links to additional Laravel cheat‑sheets for storage, schema, and mail.