Bug #79084 [Opn->Ver]: mysqlnd may fetch with wrong column indexes

Edit report at https://bugs.php.net/bug.php?id=79084&edit=1 ID: 79084 Updated by: cmb@php.net Reported by: rob-phpbugs at tigertech dot com -Summary: mysqli fetch_array returns different results on PHP 7.3+ with some column names +Summary: mysqlnd may fetch with wrong column indexes -Status: Open +Status: Verified Type: Bug Package: MySQLi related Operating System: Linux PHP Version: 7.3.13 Block user comment: N Private report: N New Comment: Ah, indeed, if mysqli uses libmysql-client, the numeric indexes are explicitly specified when inserting to the row, but if mysqlnd is used, the values with numeric indexes are added to the row, and as such may be wrong if column names are numeric strings. This likely affects PDO_MySQL as well. Previous Comments: ------------------------------------------------------------------------ [2020-01-09 18:10:45] rob-phpbugs at tigertech dot com Ah -- I believe that is exactly what's happening. My PHP 7.2 has: MysqlI Support => enabled Client API library version => 10.1.41-MariaDB And my PHP 7.3 has: MysqlI Support => enabled Client API library version => mysqlnd 5.0.12-dev - 20150407 - $Id: 7cc7cc96e675f6d72e5cf0f267f48e167c2abb23 $ So that must be the cause of this. The mysqlnd version does not appear to match the documentation for mysqli fetch_array at <https://www.php.net/manual/en/mysqli-result.fetch-array.php>, which says that it defaults to MYSQLI_BOTH. If I'm understanding correctly, that means there should be 6 keys in the output of the previous test script, for [0], [1], [2], [2007], [2008] and [2020]. Here's a different test script that shows a different weird result with mysqlnd, apparently caused by the same underlying issue: $ cat test.php <?php $mysqli = mysqli_connect("localhost", "test", "test", "test"); $sql = "SELECT 0 as test, 1 as test2, 2 as 2007, 2 as 2008, 3 as 2020"; $res = $mysqli->query($sql); $row = $res->fetch_array(); print "mysqli version: " . $mysqli->client_info . "\n"; print_r($row); $ php-7.2 test.php mysqli version: 10.1.41-MariaDB Array ( [0] => 0 [test] => 0 [1] => 1 [test2] => 1 [2] => 2 [2007] => 2 [3] => 2 [2008] => 2 [4] => 3 [2020] => 3 ) $ php-7.3 test.php mysqli version: mysqlnd 5.0.12-dev - 20150407 - $Id: 7cc7cc96e675f6d72e5cf0f267f48e167c2abb23 $ Array ( [0] => 0 [test] => 0 [1] => 1 [test2] => 1 [2] => 2 [2007] => 2 [2008] => 2 [2009] => 3 [2020] => 3 ) The mysqlnd version seems wrong; it isn't filling in the expected [3] and [4] keys, and it's added a [2009] key that should not be there. ------------------------------------------------------------------------ [2020-01-09 17:45:32] nikic@php.net I just tried your script and get the same results on 7.2 and 7.3: $ ~/php-7.2/sapi/cli/php t042.php Array ( [0] => 0 [2007] => 0 [2008] => 0 [2009] => 0 [2020] => 0 ) $ ~/php-7.3/sapi/cli/php t042.php Array ( [0] => 0 [2007] => 0 [2008] => 0 [2009] => 0 [2020] => 0 ) Do both PHP versions use mysqlnd (rather than libmysql)? ------------------------------------------------------------------------ [2020-01-09 17:23:28] rob-phpbugs at tigertech dot com I'm not sure I understand what you said, for which I apologize. Are you saying that when you run the test script on both PHP 7.2 and 7.3, it prints the same results? Could you post what the output of the script is in both cases? Here's the output of a test I just did: $ cat test.php <?php $mysqli = mysqli_connect("localhost", "test", "[redacted]", "test"); $sql = "SELECT 0 as 2007, 0 as 2008, 0 as 2020"; $res = $mysqli->query($sql); $row = $res->fetch_array(); print "PHP version: " . phpversion() . "\n"; print_r($row); $ php-7.2 test.php PHP version: 7.2.26 Array ( [0] => 0 [2007] => 0 [1] => 0 [2008] => 0 [2] => 0 [2020] => 0 ) $ php-7.3 test.php PHP version: 7.3.13 Array ( [0] => 0 [2007] => 0 [2008] => 0 [2009] => 0 [2020] => 0 ) ------------------------------------------------------------------------ [2020-01-09 08:54:20] cmb@php.net What happens should be similar to <?php $a = []; $a['2007'] = 0; $a[] = 0; ?> So I'm surprised that you're reporting that would have been different with PHP 7.2. I cannot reproduce that. ------------------------------------------------------------------------ [2020-01-08 19:30:15] rob-phpbugs at tigertech dot com I realize I included a confusing double "SELECT" in the example script because of how I was narrowing down the bug originally. That's not necessary and unrelated; the same thing happens with the simpler query of: <?php $mysqli = mysqli_connect("localhost", "user", "password", "db"); $sql = "SELECT 0 as 2007, 0 as 2008, 0 as 2020"; $res = $mysqli->query($sql); $row = $res->fetch_array(); echo print_r($row, 1); ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at https://bugs.php.net/bug.php?id=79084 -- Edit this bug report at https://bugs.php.net/bug.php?id=79084&edit=1