PHP - Using PDO with IN clause array

Question

I\'m using PDO to execute a statement with an IN clause that uses an array for its values:

$in_array = array(1, 2, 3);
$in_values = implode(\',\'         


        

Answer 1

Here is a solution for unnamed placeholders (?). If you pass $sql with question mark like "A=? AND B IN(?) " and $args where some of the elements are arrays like [1, [1,2,3]] it will return SQL string with appropriate number of placeholders - "A=? AND B IN(?,?,?)". It needs $args parameter only to find which element is array and how many placeholders it needs. You can find the small PDO extension class with this method that will run your query: https://github.com/vicF/pdo/blob/master/src/PDO.php

public function replaceArrayPlaceholders($sql, $args)
{
    $num = 0;
    preg_match_all('/\?/', $sql, $matches, PREG_OFFSET_CAPTURE);  // Captures positions of placeholders
    //echo $matches[0][1][1];
    $replacements = [];
    foreach($args as $arg) {
        if(is_array($arg)) {
            $replacements[$matches[0][$num][1]] = implode(',',array_fill(0, count($arg), '?')); // Create placeholders string
        }
        $num++;
    }
    krsort($replacements);
    foreach($replacements as $position => $placeholders) {
        $sql = substr($sql, 0, $position).$placeholders.substr($sql, $position+1); // Replace single placeholder with multiple
    }
    return $sql;
}