Direct database queries (wpdb) in Wordpress - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to get all rows from a custom table using $wpdb.

Wordpress

$results = $wpdb->[1]("SELECT * FROM wp_custom_table");

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

Aupdate

Bquery

Cinsert

Dget_results

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'query' instead of 'get_results' returns number of rows, not data.

Using 'insert' or 'update' methods for SELECT queries.

The get_results method fetches multiple rows from the database as an array of objects.

2fill in blank

medium

Complete the code to safely prepare a query with a variable using $wpdb->prepare.

Wordpress

$sql = $wpdb->prepare("SELECT * FROM wp_users WHERE ID = [1]", $user_id);

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

A%d

B%s

C%f

D%u

Attempts:

3 left

💡 Hint

Common Mistakes

Using %s for numbers can cause SQL errors or injection risks.

Using %f for integers is incorrect.

The %d placeholder is used for integers in $wpdb->prepare.

3fill in blank

hard

Fix the error in the code to insert a new row safely using $wpdb.

Wordpress

$wpdb->[1]('wp_custom_table', array('name' => $name, 'age' => $age), array([2], [3]));

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

Ainsert

Bupdate

C%s

D%d

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'update' instead of 'insert' for adding new rows.

Wrong format placeholders cause data type errors.

Use insert to add a row. The format array needs %s for string and %d for integer.

4fill in blank

hard

Fill both blanks to update a user's email safely using $wpdb.

Wordpress

$wpdb->[1]('wp_users', array('user_email' => $email), array('ID' => $user_id), array([2]), array([3]));

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

Aupdate

Binsert

C%s

D%d

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'insert' instead of 'update' to modify data.

Mixing up the order of format placeholders.

Use update to change data. The format array matches the data types: string for email, integer for ID.

5fill in blank

hard

Fill all three blanks to delete a user by ID safely using $wpdb.

Wordpress

$wpdb->[1]('wp_users', array('ID' => [2]), array([3]));

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

Adelete

B$user_id

C%d

Dupdate

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'update' instead of 'delete' to remove data.

Not using the variable for the ID in the where clause.

Use delete to remove rows. The where clause uses the user ID variable, and the format is integer %d.