I had the same problem, with a database field with type "SET" which is an enum type.
I tried to add a value which was not in that list.
The value I tried to add had the decimal value 256, but the enum list only had 8 values.
1: 1 -> A
2: 2 -> B
3: 4 -> C
4: 8 -> D
5: 16 -> E
6: 32 -> F
7: 64 -> G
8: 128 -> H
So I just had to add the additional value to the field.
Reading this documentation entry helped me to understand the problem.
MySQL stores SET values numerically, with the low-order bit of the stored value corresponding to the first set member. If you retrieve a SET value in a numeric context, the value retrieved has bits set corresponding to the set members that make up the column value. For example, you can retrieve numeric values from a SET column like this:
mysql> SELECT set_col+0 FROM tbl_name; If a number is stored into aIf a number is stored into a SET column, the bits that are set in the binary representation of the number determine the set members in the column value. For a column specified as SET('a','b','c','d'), the members have the following decimal and binary values.
SET Member Decimal Value Binary Value
'a' 1 0001
'b' 2 0010
'c' 4 0100
'd' 8 1000
If you assign a value of 9 to this column, that is 1001 in binary, so the first and fourth SET value members 'a' and 'd' are selected and the resulting value is 'a,d'.