MYSQL CASE problem with string

Guys can you give me any tip why the string values are not passed to the query. Here is the code:

Array to be used in the query:

Array ( [16] => 41 [17] => 0 [18] => 0 [19] => 0 [20] => 0 [21] 开发者_运维问答=> 0 [22] => 0 [23] => 0 [24] => 0 [25] => 0 [26] => 0 [27] => 0 [28] => 0 [29] => buu [30] => bauadaskd )

Code:

foreach ($arrAnswers as $id => $answer)
{   $update .= sprintf("WHEN '%d' THEN '%d' ", $id, $answer);
}
echo $update .= "END WHERE a_question IN ($ids) AND a_user = '{$_SESSION['current_user_id']}'";

Output

UPDATE answers SET a_answer = CASE a_question WHEN '16' THEN '41' WHEN '17' THEN '0' WHEN '18' THEN '0' WHEN '19' THEN '0' WHEN '20' THEN '0' WHEN '21' THEN '0' WHEN '22' THEN '0' WHEN '23' THEN '0' WHEN '24' THEN '0' WHEN '25' THEN '0' WHEN '26' THEN '0' WHEN '27' THEN '0' WHEN '28' THEN '0' WHEN '29' THEN '0' WHEN '30' THEN '0' END WHERE a_question IN (16,17,18,19,20,21,22,23,24,25,26,27,28,29,30) AND a_user = '19

As you can see index 29 and 30 are equal to 0 in the output even if they have their own value in the array.

Your issue is here

$update .= sprintf("WHEN '%d' THEN '%d' ", $id, $answer);

Should be

    $update .= sprintf("WHEN '%d' THEN '%s' ", $id, $answer);

You are trying to format it as integers with %d. You should use %s for strings:

$update .= sprintf("WHEN '%d' THEN '%s' ", $id, $answer);

You have wrong formatting string in your sprintf() call, use %s for strings. %d is for numbers:

$update .= sprintf("WHEN '%d' THEN '%s' ", $id, $answer);