18.104.22.168 ENUM and SET Constraints
Unless strict mode is disabled (not recommended, but see Section 5.1.10, “Server SQL Modes”), the definition of a
SET column acts as a constraint on values entered into the column. An error occurs for values that do not satisfy these conditions:
ENUMvalue must be one of those listed in the column definition, or the internal numeric equivalent thereof. The value cannot be the error value (that is, 0 or the empty string). For a column defined as
ENUM('a','b','c'), values such as
'ax'are invalid and are rejected.
SETvalue must be the empty string or a value consisting only of the values listed in the column definition separated by commas. For a column defined as
SET('a','b','c'), values such as
'a,b,c,d'are invalid and are rejected.
Errors for invalid values can be suppressed in strict mode if you use
INSERT IGNORE or
UPDATE IGNORE. In this case, a warning is generated rather than an error. For
ENUM, the value is inserted as the error member (
SET, the value is inserted as given except that any invalid substrings are deleted. For example,
'a,x,b,y' results in a value of