Bug #117058 Inconsistent Results When Using COALESCE

• Submitted: 27 Dec 2024 13:01
• Modified: 27 Dec 2024 13:08
• Reporter: Aaditya Dubey
• Status: Verified
• Category: MySQL Server: DML
• Severity: S3 (Non-critical)
• Version: 8.4.3, 8.0.40
• OS: Any
• CPU Architecture: Any

[27 Dec 2024 13:01] Aaditya Dubey

Description:
There is an inconsistency in the results when using the COALESCE function.

How to repeat:
1. Set up table t0:

CREATE TABLE t0 (c0 BIT, c1 BIT);
INSERT INTO t0 VALUES (0, 1);

2. Use COALESCE in a SELECT query:

SELECT (COALESCE(t0.c0, t0.c1)) AS c0 FROM t0;
--Result: 0x30

3. Store the result of COALESCE in another table t1 and SELECT FROM t1:

CREATE TABLE t1 AS (SELECT (COALESCE(t0.c0, t0.c1)) AS c0 FROM t0);
SELECT * FROM t1;
--Result: 0

The result should be consistent regardless of whether the result is directly selected or stored in another table.

Suggested fix:
The result should be consistent regardless of whether the result is directly selected or stored in another table.

[27 Dec 2024 13:08] MySQL Verification Team

Hello Aaditya,

Thank you for the report and feedback.
Verified as described.

regards,
Umesh