| Bug #118636 | Function DAYNAME used in arithmetic expression behaves like WEEKDAY | ||
|---|---|---|---|
| Submitted: | 10 Jul 2025 20:18 | Modified: | 13 Mar 11:17 |
| Reporter: | Roy Lyseng | Email Updates: | |
| Status: | Closed | Impact on me: | |
| Category: | MySQL Server: Optimizer | Severity: | S3 (Non-critical) |
| Version: | 8.0 | OS: | Any |
| Assigned to: | CPU Architecture: | Any | |
[13 Mar 11:17]
Edward Gilmore
Posted by developer: Added the following note to the MySQL Server 9.7.0 release notes: DAYNAME did not return the day name if used in an arithmetic expression but returned the day number instead.
Description: Since class Item_func_dayname inherits from Item_func_weekday, it behaves like an integer value, rather than a string value, in arithmetic expressions. How to repeat: select dayname("1962-03-03") + 0; Result is 5. Suggested fix: Let class Item_func_dayname inherit from Item_int_func.