- Simple Queries (4)
- Setting criteria using WHERE (5)
- Calculations (7)
- Calculations using dates (4)
- Basic joins (8)
- More exotic joins (2)
- Aggregation and grouping (8)
- Views (5)
- Subqueries (5)
- Stored procedures (5)
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- Parameters and return values (11)
- Testing conditions (1)
- Looping (3)
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- Creating tables (5)
- Temporary tables and table variables (9)
- Table-valued functions (6)
- Derived tables and CTEs (13)
- Dynamic SQL (4)
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SQL | Aggregation and grouping exercise | Show the number of events, and the earliest/latest date
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.
You can learn how to do this exercise if you attend one of more of the courses 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.
This will generate the database that you'll need to use in order to do this exercise (note that the database and script are only to be used for exercises published on this website, and may not be reused or distributed in any form without the prior written permission of Wise Owl).
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Create a query to list out the following statistics from the table of events:
You'll need to use the COUNT, MAX and MIN functions respectively.
Your query won't need a GROUP BY, as you're not grouping by anything - just a SELECT and a FROM.
Save this query as Statto, then close it down.
select c.CategoryName as Category_Name
, count(c.CategoryName) as Number_of_events
, max(e.EventDate) as Last_Date
, min(e.EventDate) as First_Date
from [dbo].[tblEvent] e
left join [dbo].[tblCategory] c
on e.CategoryID = c.CategoryID
group by c.CategoryName
order by Number_of_events desc