I am building a database to capture monthly statistics on a number of items. I want to ensure that users don't enter statistics for the same item for the same reporting period. I found the following instruction, but can't make it work:
It suggests that I create multiple primary keys in the table
When I do it, it comes back with an error: Index or primary key cannot contain a null value.
What am I doing wrong?
It suggests that I create multiple primary keys in the table
When I do it, it comes back with an error: Index or primary key cannot contain a null value.
What am I doing wrong?