Edit report at https://bugs.php.net/bug.php?id=63684&edit=1
ID: 63684 Updated by: ahar...@php.net Reported by: roastduck at qq dot com Summary: pdo sqlite round function can't work correct -Status: Open +Status: Not a bug Type: Bug Package: PDO related Operating System: windows xp PHP Version: 5.3.19 Block user comment: N Private report: N New Comment: Floating point values have a limited precision. Hence a value might not have the same string representation after any processing. That also includes writing a floating point value in your script and directly printing it without any mathematical operations. If you would like to know more about "floats" and what IEEE 754 is, read this: http://www.floating-point-gui.de/ Thank you for your interest in PHP. Previous Comments: ------------------------------------------------------------------------ [2012-12-04 08:40:02] roastduck at qq dot com Description: ------------ when I used pdo for the sql "select round(863521.777777778, 2) as a", it gets wrong result 863521.780000001 Test script: --------------- <?php $db = new PDO("sqlite:../test.s3db"); $db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); $st = $db->query('select round(863521.777777778, 2) as a'); $data = $st->fetchAll(); print_r($data); $st = $db->query('select round(372366.577777778, 2) as a'); $data = $st->fetchAll(); print_r($data); Expected result: ---------------- Array ( [0] => Array ( [a] => 863521.780000001 [0] => 863521.780000001 ) ) Array ( [0] => Array ( [a] => 372366.58 [0] => 372366.58 ) ) ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=63684&edit=1
