Archive for month: May, 2009

Enforcing Uniqueness On A Nullable Column

19 May, 2009 (11:04) | T-SQL | By: Mark V

I recently found myself needing to enforce uniqueness on a column which was nullable. To make things interesting, there were already thousands of records for which the field was already NULL and would remain NULL. A unique index on the column was not possible since I had more than one NULL value. I therefore had […]