PDO connection setup in PHP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a new PDO instance for a MySQL database.

PHP

<?php
$dsn = 'mysql:host=localhost;dbname=testdb';
$username = 'root';
$password = '';
try {
    $pdo = new PDO([1], $username, $password);
} catch (PDOException $e) {
    echo 'Connection failed: ' . $e->getMessage();
}
?>

Drag options to blanks, or click blank then click option'

A$dsn

Bdsn

C'dsn'

D$database

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the DSN as a string literal instead of the variable.

Using an undefined variable name.

The PDO constructor requires the DSN string variable, which is stored in $dsn.

2fill in blank

medium

Complete the code to set the PDO error mode to throw exceptions.

PHP

<?php
$pdo = new PDO($dsn, $username, $password);
$pdo->setAttribute(PDO::ATTR_ERRMODE, [1]);
?>

Drag options to blanks, or click blank then click option'

APDO::ERRMODE_EXCEPTION

BPDO::ERRMODE_SILENT

CPDO::ERRMODE_WARNING

DPDO::ERRMODE_FATAL

Attempts:

3 left

💡 Hint

Common Mistakes

Using PDO::ERRMODE_SILENT which hides errors.

Using a non-existent constant like PDO::ERRMODE_FATAL.

Setting PDO::ATTR_ERRMODE to PDO::ERRMODE_EXCEPTION makes PDO throw exceptions on errors.

3fill in blank

hard

Fix the error in the DSN string to connect to a PostgreSQL database named 'mydb'.

PHP

<?php
$dsn = 'pgsql:host=localhost;dbname=[1]';
$pdo = new PDO($dsn, $user, $pass);
?>

Drag options to blanks, or click blank then click option'

Atestdb

Bpostgres

Cmydb

Ddatabase

Attempts:

3 left

💡 Hint

Common Mistakes

Leaving the placeholder unchanged.

Using a wrong database name.

The DSN must specify the actual database name, which is 'mydb' here.

4fill in blank

hard

Fill both blanks to create a PDO connection with UTF-8 charset and persistent connection enabled.

PHP

<?php
$dsn = 'mysql:host=localhost;dbname=testdb;[1]';
$options = [
    PDO::ATTR_PERSISTENT => [2]
];
$pdo = new PDO($dsn, $user, $pass, $options);
?>

Drag options to blanks, or click blank then click option'

Acharset=utf8mb4

Btrue

Cfalse

Dcharset=utf8

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'charset=utf8' instead of 'utf8mb4'.

Setting persistent connection to false or omitting it.

The DSN must include 'charset=utf8mb4' for UTF-8 support, and persistent connection is enabled by setting PDO::ATTR_PERSISTENT to true.

5fill in blank

hard

Fill all three blanks to prepare a PDO statement, bind a parameter, and execute it.

PHP

<?php
$stmt = $pdo->[1]('SELECT * FROM users WHERE id = :id');
$stmt->[2](':id', $userId, PDO::PARAM_INT);
$result = $stmt->[3]();
?>

Drag options to blanks, or click blank then click option'

Aprepare

BbindValue

Cexecute

Dquery

Attempts:

3 left

💡 Hint

Common Mistakes

Using query() instead of prepare().

Using bindParam() instead of bindValue() (both work but bindValue is simpler here).

Forgetting to execute the statement.

You prepare the statement with prepare(), bind the parameter with bindValue(), and run the query with execute().