Bug #17922 | Concat with NULL content are no concatening | ||
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Submitted: | 5 Mar 2006 3:48 | Modified: | 5 Mar 2006 14:24 |
Reporter: | Luis A S Junior Camargo | Email Updates: | |
Status: | Not a Bug | Impact on me: | |
Category: | MySQL Server | Severity: | S3 (Non-critical) |
Version: | 5.0.18 | OS: | Windows (Windows 2000 SP4) |
Assigned to: | CPU Architecture: | Any |
[5 Mar 2006 3:48]
Luis A S Junior Camargo
[5 Mar 2006 6:19]
Valeriy Kravchuk
Thank you for a problem report. Sorry, but it is not a bug. It is inteded, documented and correct behaviour. Please, read the manual (http://dev.mysql.com/doc/refman/5.0/en/string-functions.html): "CONCAT() returns NULL if any argument is NULL." It is Oracle that equals '' with NULL, and thus just use '' when NULL is concatenated. It was wrong decision, according to one of Codd rules for proper RDBMS.
[5 Mar 2006 14:24]
Luis A S Junior Camargo
Sorry for the post, only to comment, i have solved my problem with function CONCAT_WS: mysql> select concat_ws('',NULL,'test'); +---------------------------+ | concat_ws('',NULL,'test') | +---------------------------+ | test | +---------------------------+ 1 row in set (0.00 sec) very thanks, goodbye