Bug #79084 [Opn]: mysqli fetch_array returns different results on PHP 7.3+ with some column names

Edit report at https://bugs.php.net/bug.php?id=79084&edit=1 ID: 79084 User updated by: rob-phpbugs at tigertech dot com Reported by: rob-phpbugs at tigertech dot com Summary: mysqli fetch_array returns different results on PHP 7.3+ with some column names Status: Open Type: Bug Package: MySQLi related Operating System: Linux PHP Version: 7.3.13 Block user comment: N Private report: N New Comment: 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. Previous Comments: ------------------------------------------------------------------------ [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); ------------------------------------------------------------------------ [2020-01-08 19:03:37] rob-phpbugs at tigertech dot com Description: ------------ If a query has column names that are all numeric, like this: SELECT * FROM (SELECT 0 as 2007, 0 as 2008, 0 as 2020) AS x; And you use "fetch_array()" on it, PHP 7.2 gives this result: Array ( [0] => 0 [2007] => 0 [1] => 0 [2008] => 0 [2] => 0 [2020] => 0 ) But PHP 7.3 and 7.4 give this result: Array ( [0] => 0 [2007] => 0 [2008] => 0 [2009] => 0 [2020] => 0 ) The latter is wrong: it should not contain "2009", and it is missing "[1]" and "[2]". Test script: --------------- <?php $mysqli = mysqli_connect("localhost", "user", "password", "db"); $sql = "SELECT * FROM (SELECT 0 as 2007, 0 as 2008, 0 as 2020) AS x"; $res = $mysqli->query($sql); $row = $res->fetch_array(); echo print_r($row, 1); Expected result: ---------------- Array ( [0] => 0 [2007] => 0 [1] => 0 [2008] => 0 [2] => 0 [2020] => 0 ) Actual result: -------------- Array ( [0] => 0 [2007] => 0 [2008] => 0 [2009] => 0 [2020] => 0 ) ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=79084&edit=1