Question

I am trying to execute a PHP/MySQL query to select a set of columns and clear the fields for a particular record:

$sth = $dbh->query("SELECT column_name
                    FROM information_schema.columns
                    WHERE table_name = 'users'
                    AND column_name like '%_abc'");

$rows = $sth->fetchAll();

foreach ($rows as $row){

    $sth = $dbh->prepare("UPDATE users
                          SET $row = NULL
                          WHERE user_id = $user_id");

    $sth->execute();        

}

However, I am getting the following error:

Fatal error: Uncaught exception 'PDOException' with message 'SQLSTATE[42S22]: 
Column not found: 1054 Unknown column 'Array' in 'field list'

Any ideas?

Answer 1

Your $row is an array. Try

foreach ($rows as $id => $value {
   ... SET $value = NULL ...
}

You can look at $row using:

var_dump($row);