MySqlcan't set a nullable column to null - mysql

Question

I'm trying to insert a row into a table named Booklets which has a nullable column BookletSubjectID. The insert is failing because
'BookletSubjectID' cannot be null
Here's my MySQL session copied verbatim. I must be missing something really obvious, but can't see it.
mysql> desc Booklets;
+----------------------+---------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+----------------------+---------------+------+-----+---------+----------------+
| BookletID | int(11) | NO | PRI | NULL | auto_increment |
| MemberID | int(11) | NO | MUL | NULL | |
| Name | varchar(255) | YES | | NULL | |
| Description | varchar(1000) | YES | | NULL | |
| RelationshipTypeID | varchar(12) | YES | MUL | NULL | |
| RateTypeID | varchar(2) | YES | MUL | NULL | |
| PrivTypeID | varchar(2) | NO | MUL | NULL | |
| PhotoAlbumID | int(11) | YES | MUL | NULL | |
| VideoAlbumID | int(11) | YES | MUL | NULL | |
| BookletSubjectTypeID | varchar(2) | NO | MUL | NULL | |
| BookletSubjectID | int(11) | YES | MUL | NULL | |
| Deleted | tinyint(1) | NO | | 0 | |
| Credt | datetime | NO | | NULL | |
| Updt | datetime | YES | | NULL | |
+----------------------+---------------+------+-----+---------+----------------+
14 rows in set (0.00 sec)
mysql> INSERT Booklets (MemberID, Name, PrivTypeID, BookletSubjectTypeID, Deleted, Credt)
VALUES (546502, 'dddd','pu', 'no', 1, NOW());
ERROR 1048 (23000): Column 'BookletSubjectID' cannot be null
Thanks,
Don

Answer 1

It seems that:
If a table has a column which is part of a multi-column primary key then that column
cannot be nullable.
See this bug report and its response.