Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Databases Querying Relational Databases Set Operations Except Operations

Andrew Blackwell
Andrew Blackwell
13,264 Points
Posted by Andrew Blackwell
Andrew Blackwell
13,264 Points

Add other columns to EXCEPT query?

This is a theoretical question, but in the video Andrew Chalkley demonstrates that it is not possible to Select the ID column in the EXCEPT query, as it would be taken into account in the exception logic and compared to the id column in the second part of the query. My question is: how do I go about it if I DO want to add other columns to the query result (e.g. the id column)? Is there any short way of going about this, or do I have to do some kind of compound query (e.g. where I nest the EXCEPT query inside a larger query with an IN operator)?

2 Answers

Steven Parker
Steven Parker
231,268 Points
Steven Parker
Steven Parker
231,268 Points

If you want other columns, a subquery or JOIN might be useful.

But you would not need EXCEPT:

SELECT ForeignMakeID, MakeName FROM ForeignMake
WHERE MakeName NOT IN (SELECT MakeName FROM Make);
Andrew Blackwell
Andrew Blackwell
13,264 Points
Andrew Blackwell
Andrew Blackwell
13,264 Points

Thanks, Steven - that solves it :-)