Laravel's database query builder provides a convenient, fluent interface to creating and running database queries.
- It uses PDO parameter binding to protect your application against SQL injection. There is no need to clean strings passed as bindings.
Joins
To perform a basic "
inner join", you may use the
join() method on a query builder instance.
The first argument is the name of the table you need to join to; the remaining arguments specify the relation of the columns for the join.
- You can join to multiple tables in a single query:
$users = DB::table('users')
->join('contacts', 'users.id', '=', 'contacts.user_id')
->join('orders', 'users.id', '=', 'orders.user_id')
->select('users.*', 'contacts.email', 'orders.price')
->get();
- To perform a "
left join" query, use the
leftJoin() method, in the same way as the
join() method.
$users = DB::table('users')
->leftJoin('posts', 'users.id', '=', 'posts.user_id')
->get();
Unions
To "
union" two queries together, create an initial query and use the
union() method to union it with a second query.
$first = DB::table('users')->whereNull('first_name');
$users = DB::table('users')->whereNull('last_name')
->union($first)->get();
- Documentation:
Laravel - Database: Query Builder
Daily Test with Code Example
HTML
CSS
JavaScript
PHP-MySQL
Which tag renders as emphasized text, displaying the text oblique?
<strong> <pre> <em><p>Web development courses: <em>CoursesWeb.net</em></p>
Which CSS property defines the space between the element border and its content?
margin padding positionh3 {
padding: 2px 0.2em;
}
Click on the method which returns the first element that matches a specified group of selectors.
getElementsByName() querySelector() querySelectorAll()// gets first Div with class="cls", and shows its content
var elm = document.querySelector("div.cls");
alert(elm.innerHTML);
Indicate the PHP variable that contains data from a form sent with method="post".
$_SESSION $_GET $_POSTif(isset($_POST["field"])) {
echo $_POST["field"];
}