Mismatched data types: If the condition in the check constraint does not match the data type of the corresponding field, the constraint will not be effective.
Index Conflict: If the condition in a check constraint conflicts with an index on the table, the constraint may not be effective.
Issue with data importing: If the conditions necessary to trigger a check constraint are not met during data insertion or update, then the constraint will not take effect.
Database version issue: Certain versions of MySQL may have bugs or inadequate support for check constraints, resulting in these constraints not functioning properly.
Trigger issue: If other triggers make changes to the data during insertion or update, it may cause the check constraint to not work effectively.
Permission issue: It may be due to the user not having enough permissions to create or modify the check constraint, causing the constraint to not take effect.
