How do you use a variable multiple times when using $wpdb->prepare ?
If your prepared SQL statement needs to refer to a variable more than once you need to include it as a parameter multiple times.
For example, the SQL query below refers to the user_id twice – both for the use_id and conrtributor_use_id column
SELECT id, title, user_id, contributor_user_id WHERE user_id = 1 OR contributor_user_id = 1
To prepare this statement you would need to do this
$wpdb->prepare( "SELECT id, title, user_id, contributor_user_id WHERE user_id = %d OR contributor_user_id = %d", $user_id, $user_id );