Bug #78199 CONCAT() with CASE in derived table returns unexpected results

• Submitted: 25 Aug 2015 6:25
• Modified: 17 Feb 2021 14:24
• Reporter: Yu Asano
• Status: Can't repeat
• Category: MySQL Server: Parser
• Severity: S3 (Non-critical)
• Version: 5.6.26,5.5.25,5.5.20
• OS: Any
• CPU Architecture: Any
• Tags: case, concat, derived table

[25 Aug 2015 6:25] Yu Asano

Description:
The query:
SELECT * FROM (SELECT CONCAT( CASE 1 WHEN 1 THEN 1 END, '}}' ) as a) as b;

Expected result:
+------+
| a    |
+------+
| 1}}  |
+------+

Actual Result:
+------+
| a    |
+------+
| 1}   |
+------+

How to repeat:
See description.

Suggested fix:
Correct the query result as expected one.

[25 Aug 2015 7:22] MySQL Verification Team

Hello Yu Asano,

Thank you for the report and test case.
Verified as described on 5.6.26.

Thanks,
Umesh

[17 Feb 2021 14:24] Erlend Dahl

Not reproducible on 5.7/8.0. 5.5 and 5.6 are EOL.