Laravel Course

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.


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', '', '=', 'contacts.user_id')
 ->join('orders', '', '=', 'orders.user_id')
 ->select('users.*', '', 'orders.price')
- To perform a "left join" query, use the leftJoin() method, in the same way as the join() method.
$users = DB::table('users')
 ->leftJoin('posts', '', '=', 'posts.user_id')


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')

- Documentation: Laravel - Database: Query Builder

Daily Test with Code Example

What attribute makes the input text box to not be modified by the user?
checked="checked" readonly="readonly" disabled="disabled"
<input type="text" value="fixed-value" readonly="readonly" name="a_name" />
What CSS property allows you to create rounded corners in your webpage design?
background-size border-size border-radius
.class {
  border:2px solid blue;
What instruction displays a confirmation dialog box to the viewer, who must then click OK or Cancel to proceed?
indexOf() confirm() prompt()
var ques = window.confirm("The result of 0+0 is 0?");
if (ques) alert("Corect");
else alert("Incorrect");
Indicate the PHP function that returns the lowest number of the parameter values.
floor() ceil() min()
$min_nr = min(12, 8, 25, 13);
echo $min_nr;        // 8
MySQL Database, Query Builder: Join and Union

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