Following are the limitations of MySQL ENUMs −
Enumeration value cannot be an expression
we cannot use expressions as enumeration members even one that evaluates to a string value.
Example
For example, we can use even CONCAT function which leads to the evaluation of a string.
The following query will not work −
mysql> create table limit_enum(number ENUM('one', 'two', CONCAT('t','wo'));Cannot employ a user variable as enumeration member
Another limitation is that we cannot use a user variable as enumeration member. Hence the following query will not work −
mysql> SET @mynumber = 'two';
Query OK, 0 rows affected (0.04 sec)
mysql> Create table limit_enum(number ENUM('one', @mynumber, 'three'));