| Bug #586 | CONCAT_WS() has wrong handling of empty strings | ||
|---|---|---|---|
| Submitted: | 4 Jun 2003 12:40 | Modified: | 10 Dec 2003 17:54 |
| Reporter: | Peter Zaitsev (Basic Quality Contributor) | ||
| Status: | Closed | ||
| Category: | Server | Severity: | S3 (Non-critical) |
| Version: | 4.0 | OS: | Any (all) |
| Assigned to: | Bugs System | Target Version: | |
[5 Jun 2003 7:03]
Jani Tolonen
Fixed. Regards, Jani
[10 Dec 2003 17:54]
Michael Widenius
This was fixed in 4.0.14 as this was a clear bug in how concat_ws() was supposed to work from the start If you want to skip an empty string and NULL's for an argument you can use: CONCAT_WS(IF(a<>"",a,NULL))
[20 Apr 2004 0:23]
Shayne Paddock
I'm running 4.1.1 and I still see this bug??? -Shayne Shayne_Paddock@hotmail.com
[7 Jul 2004 13:13]
Mike Price
Was this really a bug? I have been using concat_ws for a long time to separate the fields of an address. Having upgraded to v4, all my clients address databases have become very untidy. Michael W's solution is not viable for using the function with mutiple arguments. Having the old version on concat_ws (perhaps renamed eg concat_wsx??) in future versions would be very useful.
[11 Jan 2007 14:53]
torp
It's 2007 now, but I agree with Mike Price. Maybe the old CONCAT_WS did not work as meant, but it was very handy that way. Now the separator will be added, even after empty results. Ugly!
Description: CONCAT_WS has wrong handling of empty string, handling them same way as NULL, instead of proper concatenation. This shall be fixed in 4.1 as users in MySQL 4.0 may depends on old behavior. How to repeat: mysql> select concat_ws("/","a",NULL,"b"); +-----------------------------+ | concat_ws("/","a",NULL,"b") | +-----------------------------+ | a/b | +-----------------------------+ 1 row in set (0.12 sec) mysql> select concat_ws("/","a","","b"); +---------------------------+ | concat_ws("/","a","","b") | +---------------------------+ | a/b | +---------------------------+ 1 row in set (0.00 sec) Last shall return: "a//b"