Bug->Doc #60333 [Opn]: fetch_field() length multiplied by 3 in mysqlnd

Edit report at https://bugs.php.net/bug.php?id=60333&edit=1 ID: 60333 Updated by: johannes@php.net Reported by: danielc at analysisandsolutions dot com Summary: fetch_field() length multiplied by 3 in mysqlnd Status: Open -Type: Bug +Type: Documentation Problem Package: MySQLi related Operating System: linux PHP Version: 5.4SVN-2011-11-19 (SVN) Block user comment: N Private report: N New Comment: The behavior is correct. We report the same data as we retrieve from the server. The MySQL documentation has more details on this: http://dev.mysql.com/doc/refman/5.5/en/c-api-data-structures.html The key part here is that the data is returned in bytes. On a connection using UTF-8 these are 3 bytes per character. The PHP documentation should be made more clear on this. Previous Comments: ------------------------------------------------------------------------ [2012-01-13 18:09:05] danielc at analysisandsolutions dot com Can this please be fixed before PHP 5.4 goes out the door? ------------------------------------------------------------------------ [2011-11-21 18:04:38] danielc at analysisandsolutions dot com That may be the case, but having UTF-8 fields is legit and the answers from libmysql and mysqlnd should be the same. ------------------------------------------------------------------------ [2011-11-21 17:59:23] william dot bailey at cowboysfromhell dot co dot uk I think this might be down to what encoding the connection is using. The length in bytes of a mysql utf8 CHAR(2) field is 6. If you issue a $db->query('SET NAMES latin1'); before the CREATE TABLE then you should get the results you are expecting. ------------------------------------------------------------------------ [2011-11-19 02:38:53] danielc at analysisandsolutions dot com Description: ------------ Running PHP 5.4 compiled from svn earlier today. The "length" values from fetch_field() are multiplied by 3 when building mysqli against mysqlnd. The values are correct when building against libmysql. Test script: --------------- $db = new mysqli(null, $_ENV['MYSQL_TEST_USER'], $_ENV['MYSQL_TEST_PASSWD'], $_ENV['MYSQL_TEST_DB'], null, $_ENV['MYSQL_TEST_SOCKET']); $result = $db->query("CREATE TEMPORARY TABLE phptest_fk ( txt TEXT NULL, chr2 CHAR(2) default 'df' NOT NULL, chr10 CHAR(10) default 'df' NOT NULL)"); if (!$result) { echo "OOPS: $db->error\n"; exit(1); } $result = $db->query("INSERT INTO phptest_fk VALUES ('One', 'c1')"); $result = $db->query("SELECT * FROM phptest_fk"); $info = $result->fetch_field(); echo "$info->name $info->length\n"; $info = $result->fetch_field(); echo "$info->name $info->length\n"; $info = $result->fetch_field(); echo "$info->name $info->length\n"; Expected result: ---------------- txt 65535 chr2 2 chr10 10 Actual result: -------------- txt 196605 chr2 6 chr10 30 ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=60333&edit=1