Bug #119414 0.0 is treated differently

• Submitted: 17 Nov 2025 23:55
• Modified: 7 Dec 2025 21:11
• Reporter: wenwen wen
• Status: Not a Bug
• Category: MySQL Server: Optimizer
• Severity: S3 (Non-critical)
• Version: mysql Ver 9.4.
• OS: MacOS
• CPU Architecture: Any

[17 Nov 2025 23:55] wenwen wen

Description:
select '0' union select -5.0 + 5.0 gives only ’0’ but select '0' union
select 0.0 gives ’0’ and ’0.0’.

How to repeat:
you just union '0' with any operation that could result in 0.0.

[7 Dec 2025 21:11] Roy Lyseng

Not a bug.
-5.0 + 5.0 is computed as '0', which is same as '0' from other part of UNION.