Bug #119 CONCAT() returns NULL for strings longer than 1047552 bytes
Submitted: 4 Mar 2003 9:31 Modified: 4 Mar 2003 9:51
Reporter: Alexander Keremidarski Email Updates:
Status: Not a Bug Impact on me:
None 
Category:MySQL Server Severity:S3 (Non-critical)
Version:3.23 OS:
Assigned to: Alexander Keremidarski CPU Architecture:Any

[4 Mar 2003 9:31] Alexander Keremidarski
Description:
See below.

How to repeat:
select isnull(concat(repeat('A', 1047552))), 
       isnull(concat(repeat('A', 1047553)));

+--------------------------------------+--------------------------------------+
| isnull(concat(repeat('A', 1047552))) | isnull(concat(repeat('A', 1047553))) |
+--------------------------------------+--------------------------------------+
|                                    0 |                                    1 |
+--------------------------------------+--------------------------------------+
[4 Mar 2003 9:51] Alexander Keremidarski
Thank you for taking the time to write to us, but this is not
a bug. Please double-check the documentation available at
http://www.mysql.com/documentation/ and the instructions on
how to report a bug at http://bugs.mysql.com/how-to-report.php

The problem occurs when string exceeds value of max_allowed_packet which is  1047552 by default.