WISE OWL EXERCISES
- Simple Queries (4)
- Setting criteria using WHERE (5)
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- Calculations using dates (4)
- Basic joins (8)
- More exotic joins (2)
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- Stored procedures (5)
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- Transactions (5)
- Creating tables (5)
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- Table-valued functions (6)
- Derived tables and CTEs (13)
- Dynamic SQL (4)
- Pivots (2)
- Triggers (2)
- Archived (70)
SQL | Subqueries exercise | Show countries with more than 8 events, using a subquery
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 course listed below!
- Go into SQL Server Management Studio;
- Open the SQL file you've just unzipped (you can press CTRL + O to do this); then
- Execute this script.
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Write a query which lists out countries which have more than 8 events, using a correlated subquery rather than HAVING.
That is: list the names of countries from the countries table where for each country the number of events matching the country's id is more than 8.
If you list the countries in alphabetical order, you should get:
Although your query should be easy to read, one disadvantage is that you can't see how many events there were for each country.
Save this query as Eventful countries, then close it down.