How do you implement database transactions in Laravel?

Laravel provides several ways to handle database transactions:\n\n**Automatic Transactions:**\n```php\nDB::transaction(function () {\n DB::table('users')->update(['votes' => 1]);\n DB::table('posts')->delete();\n});\n```\n\n**Manual Transactions:**\n```php\nDB::beginTransaction();\n\ntry {\n DB::table('users')->update(['votes' => 1]);\n DB::table('posts')->delete();\n \n DB::commit();\n} catch (\Exception $e) {\n DB::rollBack();\n throw $e;\n}\n```\n\n**Nested Transactions:**\n```php\nDB::transaction(function () {\n DB::table('users')->update(['votes' => 1]);\n \n DB::transaction(function () {\n DB::table('posts')->delete();\n });\n});\n```\n\n**With Retry Logic:**\n```php\nDB::transaction(function () {\n // Database operations\n}, 5); // Retry 5 times on deadlock\n```