Using a query with IN in T-SQL

Can I use this in T-SQL:
 
where c.asset_id = v.parent_asset_id and
(c.asset_type,d.asset_type,v.assoc_type) in (select
m.asset_key,n.asset_key,o.association_key from dbo.t_association_rule o,
dbo.t_asset_master m, dbo.t_asset_master n)

    Requires Free Membership to View

    Login

SQL Server does not support using the IN operator in that way, that is, evaluating whether a set of two or more columns are "in" a sub-query. I have a couple of solutions which I believe accomplish the same thing. One uses an inner join, while the other involves using the EXISTS operator and a correlated sub-query. Using an employee table as an example, here's the first:

select e.FirstName, e.LastName
  from Emp e inner join OtherEmp oe 
    on ( oe.FirstName = e.FirstName and 
         oe.LastName = e.LastName );
Here's the second solution:
select e.FirstName, e.LastName
  from Emp e
  where exists ( select * from OtherEmp oe
                   where oe.FirstName = e.FirstName 
                     and oe.LastName = e.LastName );
That fact that in your particular situation, you use columns from different tables should not affect the effectiveness of these two approaches.

For More Information

  • What do you think about this answer? E-mail the edtiors at editor@searchDatabase.com with your feedback.
  • The Best SQL Web Links: tips, tutorials, scripts, and more.
  • Have an SQL tip to offer your fellow DBAs and developers? The best tips submitted will receive a cool prize. Submit your tip today!
  • Ask your technical SQL questions -- or help out your peers by answering them -- in our live discussion forums.
  • Ask the Experts yourself: Our SQL, database design, Oracle, SQL Server, DB2, metadata, object-oriented and data warehousing gurus are waiting to answer your toughest questions.

This was first published in May 2002

Join the conversationComment

Share
Comments

    Results

    Contribute to the conversation

    All fields are required. Comments will appear at the bottom of the article.
    Back to top