string return on *affected-rows methods

[staabm]

https://www.php.net/manual/en/mysqli.affected-rows.php Mentions the following note:

If the number of affected rows is greater than the maximum int value (PHP_INT_MAX), the number of affected rows will be returned as a string.

Other similar functions don‘t contain the same note, e.g.

• db2_num_rows
• oci_num_rows
• pdostatement::rowCount
• sqlsrv_rows_affected
• …

Does the same note apply to them and therefore they might also return string on big numbers?

[kamil-tekiela]

No.

On 32bit systems the number is converted from uint64_t to int32_t. See PDO_MySQL. On 64 bit, the cast is from uint64_t to int64_t.

I am not sure how exactly the other extensions deal with this but they all seem to be casting to ZEND_LONG. It might be that the numbers that exceed signed int (int64_t) are undefined behaviour.

Anyway, the documentation seems to be correct. Sorry, if I didn't provide a more technical answer. Perhaps someone else can chime in to give a better explanation.

P.S. I just tried inserting an unsigned bigint using mysqli and I got "%I64u" as a return of insert_id. I am not sure what it means, but maybe it signifies an overflow. lastInsertId on PDO_MySQL also overflows giving string(20) "-9223372036854775808" so I assume the same would happen with rowCount()

[cmb69]

I am not sure how exactly the other extensions deal with this but they all seem to be casting to ZEND_LONG.

Hmm, that might be an issue on 32bit systems, though.

I just tried inserting an unsigned bigint using mysqli and I got "%I64u" as a return of insert_id.

Ugh, that would be the format specifier printed out literally, what is not supposed to happen, but happens due to https://github.com/php/php-src/blob/2119ba215aacf0b3964694a34aa39037e032abf6/UPGRADING.INTERNALS#L98-L101. Apparently, the required update had not been applied to ext/mysqli on Windows. Bug.

[cmb69]

I'm going to close this ticket, since it is not really actionable as is. Please file new tickets, if these functions don't behave as documented.