Exercise: Use outer joins to show companions who have no episodes

This exercise is provided to allow potential course delegates to choose the correct Wise Owl Microsoft training course, and may not be reproduced in whole or in part in any format without the prior written consent of Wise Owl.

The answer to the exercise will be included and explained if you attend the Wise Owl course listed below!

Category ==> SQL  (115 exercises)
Topic ==> More exotic joins  (3 exercises)
Level ==> Average difficulty
Course ==> Introduction to SQL
Before you can do this exercise, you'll need to download and unzip this file (if you have any problems doing this, click here for help).

You need a minimum screen resolution of about 700 pixels width to see our exercises. This is because they contain diagrams and tables which would not be viewable easily on a mobile phone or small laptop. Please use a larger tablet, notebook or desktop computer, or change your screen resolution settings.

If you haven't already done so, run the script in the above folder to generate the Doctor Who database.

The database contains details of companions, and the episodes each appeared in:

Episodes and companions

Each companion can appear in one or more episodes.

Use this to list the names of the companions who haven't featured in any episodes.  You should find there's one of them, but we won't spoil the surprise by saying who it is!

Create a query based on the companions table, with an outer join to the episode companion table.

Save this query as outre.sql (that's neither a misspelling nor a funny joke), and close it down.

This page has 0 threads Add post