[hibernate-issues] [Hibernate-JIRA] Commented: (HHH-2235) Support for null map-keys in <map> mappings

[ http://opensource.atlassian.com/projects/hibernate/browse/HHH-2235?page=c... ] Ulf gohde commented on HHH-2235: -------------------------------- sorry was in a hurry... lots of typos in the previous comment. Let's do it again: I don't agree with this statement. You don't have to have a primary key at all, instead you can use a UNIQUE CONSTRAINT and all databases support null values in a UNIQUE CONSTRAINT. Imagine a table like DOC_TYPE, STATE, WATERMARK; unique constraint(DOC_TYPE, STATE) to specify watermarks to be imprinted in certain documents. For some document types you want to be able to configure the watermarks based on some possible states of the document, for other types you just want one watermark independent of the state. In that situation it makes perfect sense to have null in your unique constraint. Otherwise you have to come up with a weird "reserved" state and all your code has to be aware of that "special" value. When I define the key in hibernate based on this unique constraint, I am getting a null object back when querying with "where doctype='xyz' and state is null". Is this by design at the moment meaning it would be a change request or is it a bug? -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://opensource.atlassian.com/projects/hibernate/secure/Administrators.... - For more information on JIRA, see: http://www.atlassian.com/software/jira