Inserting a string into an SQL query to change the order with PHP

Question

I want to insert a 'COLLATE NOCASE' before each ORDER BY clause of an SQLite query. This is what I have so far:

     $string = preg_replace('~(ORDER\s+BY\s+`?.+`?)\s+([ASC|DESC]?)~iU', '$1 COLLATE NOCASE $2', $string);

The output is:

SELECT `x`, `y` FROM `test` ORDER BY `x` COLLATE NOCASE ASC, `z` ASC LIMIT 0, 10

The first instance is matched and replaced. The second instance is not replaced (because of the ORDER BY clause in the pattern).

Answer 1

Change your regex into:

$query = "SELECT `x`, `y` FROM `test` ORDER BY `x` ASC, `z` ASC LIMIT 0, 10";
$query = preg_replace('~(ORDER BY|,)(\s+\S+)\s+(?=ASC|DESC)~iU', ' $1$2 COLLATE NOCASE ', $query);
echo $query,"\n";

Output:

SELECT `x`, `y` FROM `test` ORDER BY `x` COLLATE NOCASE ASC, `z` COLLATE NOCASE ASC LIMIT 0, 10