Question

I am attempting to replace all records for a give day in a certain table. The table has a composite primary key comprised of 7 fields. One such field is date.

I have deleted all records which have a date value of 2/8/2010. When I try to then insert records into the table for 2/8/2010, I get a primary key violation. The records I am attempting to insert are only for 2/8/2010.

Since date is a component of the PK, shouldn’t there be no way to violate the constraint as long as the date I’m inserting is not already in the table?

Thanks in advance.

Answer 1

You could have duplicates in the data you are inserting.

Also, it is a very, very, very poor practice to have a primary key that consists of 7 fields. The proper way to handle this is to havea surrogate identity key and a unique index on the seven fields. Joining to child tables on 7 feilds is a guarantee of poor performance and updating records when they have child records becomes a nightmare and can completely lock up your system. A primary key should be unique adnit should NEVER change.