What potential pitfalls should be avoided when using PHP to connect to a database in WordPress?

One potential pitfall when using PHP to connect to a database in WordPress is not properly sanitizing user input, which can lead to SQL injection attacks. To avoid this, always use prepared statements or escape user input before executing SQL queries. Example of using prepared statements in PHP to connect to a database in WordPress: 

global $wpdb;
$user_id = 1;
$prepared_query = $wpdb->prepare( "SELECT * FROM wp_users WHERE ID = %d", $user_id );
$results = $wpdb->get_results( $prepared_query );
foreach ( $results as $result ) {
    echo $result->user_login;
}

Keywords

WordPress PHP database connection SQL injection error handling

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