Question

I have Names table:

ID           Name 
1            Ken
2            John
3            Tom

…

I have following variable in c# code:
var names; //which is list of some names like “ken, Tom”

I need a query that goes through Names table and gets all names that are not in names variable.

So in above case if i run a query result should be John.

I am not sure how to write a query in this problem i am iterating through names and running query again and again and i think this is really bad way to do it. Can someone please suggest what is most efficient way to do this?

Answer 1

If you need to do it in T-SQL, you could do something like:

SELECT *
FROM table
WHERE Name NOT IN (<<comma separated list of values here>>)

That could be done inline or in a stored procedure.

If you can use Entity Framework (you indicate .Net 4.0, so you should be able to), then you can use something similar to this answer:

Linq-to-sql Not Contains or Not in?