[NATIONAL] CHAR[(M)] [CHARACTER SET charset_name] [COLLATE collation_name]
A fixed-length string that is always right-padded with spaces to the specified
length when stored.
M represents the column length in characters. The range
M is omitted, the length is
CHAR(0) columns can contain 2 values: an empty string or NULL. Such columns cannot be part of an index. The CONNECT storage engine does not support CHAR(0).
Note: Trailing spaces are removed when
CHAR values are retrieved
PAD_CHAR_TO_FULL_LENGTH SQL mode is enabled.