Question

I have a table say T in SQL Server 2005 database and it has two columns say A and B, which more often than not won’t have any values in them.
How to check whether A and B are empty (has all zero length strings) or not?

I have this naive way of doing it –

select count(*) as A_count from T where A <> ''

Let’s assume A has data type varchar.

I was wondering whether I can get the same information using a system table, and if so would that be faster than this query?

cheers

Answer 1

If your column is nullable, you will have to modify your query as follows:

select count(*) as A_count from T where COALESCE(A, ”) <> ”

otherwise you will not count nulls.