Can a uniqueidentifier have a default value?

_{Sunday, August 19, 2012 5:05 PM | 1 vote}

Hi,

Is it possible to set a uniqueidentifier field (non primary key) to a default value, say 00000000-0000-0000-0000-000000000000.

Reason: I have a proc that I need to pass some value to this field, even when the field is not needed. I store several Visit types in this table (Attendance) and only one of them would use this field. And I prefer not to have to write a separate proc to accommodate this situation. What is the best way to handle this for the uniqueidentifier field? Thanks for any suggestions.

_{Sunday, August 19, 2012 5:30 PM ✅Answered | 1 vote}

Yes, a uniqueIedentifier can have a default value, although it is more typically the newId() function.

_{Sunday, August 19, 2012 5:37 PM ✅Answered | 1 vote}

Adding to Kent's response, you might consider using NULL to indicate the value is not applicable.  The application can pass DBNull.Value in that case.

Dan Guzman, SQL Server MVP, http://weblogs.sqlteam.com/dang/

_{Sunday, August 19, 2012 5:52 PM}

Hi Dan,

Thanks for the reply. I though about using NULL also, but I thought it may cause an issue when I wanted to link the two tables together in a query, hence the default 0000 value. I figured, if I could put a 0000 default value in the Lookup table (GroupSchedule table, has a uniqueIedentifier as a PK ) and set the GroupScheduleId field in the Primary table (Attendance, uniqueIedentifier is not the PK) I could use it to get the descriptive info for the group from the GroupSchedule table when linking it in a query.

I guess this could still work cause if I run a query and say one of the rows has the GroupScheduleId set to null, the descriptive information from the GroupSchedule table will also be null. I'll give this a shot and see how it goes. Thanks

Michael