Updating from Pear DB to Pear MDB2 - what is the developer trying to do in the query?

Question

I'm updating a site from pear DB to MDB2, I've managed to get quite far but I've come unstuck on a query I'm not sure what they are trying to achieve here.

Can anyone explain.

Here it is

        $bookRes = $mdb2->query(("SELECT * FROM book WHERE (".join(' OR ', $sqlParams).") $categorySQL ORDER BY title"), $sqlValues);
        while ($row = $bookRes->fetchRow()) {
            $row['type'] = 'book';
            $booksPossibles[] = $row;
        }

Answer 1

I would need to see a bit more of the code to be sure, but this appears to be a simple dynamic generation of a SELECT statement where various criteria, with placeholders, stored in the $sqlParams array are being added to the WHERE clause and the values for those criteria are specified in the $sqlValues variable, again presumably an array.

so $sqlParams and $sqlValues might look like:

$sqlParams = array("val1 > ?", "val2 = ?");
$sqlValues = array(2, 4);

(It helps to know that the join keyword in PHP is just an alias for implode.)