SQL | Aggregation and grouping exercise | Show the total number of events for each century

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The answer to the exercise will be included and explained if you attend one of more of the courses listed below!

Software ==> SQL  (198 exercises)
Version ==> Any version of SQL Server
Topic ==> Aggregation and grouping  (8 exercises)
Level ==> Harder than average
Courses ==> Introduction to SQL  /  Fast-track SQL
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Create a query to show the following information:

Events by century

You'll need to calculate the century for each event date, and group by this.

 

To get the top row giving the grand total in the same query, encase your GROUP BY expression in the CUBE function.

Save this query as Passing of the centuries, then close it down.

This page has 1 thread Add post
linjom   Reply to linjomReply
23 Apr 18 at 07:33

I am getting different result.. 

NULL    459
18th Century    4
19th Century    14
20th Century    396
21st Century    45

for both rollup and cube.. is this right? Final total same as site.

 

Zerish   Reply to ZerishReply
22 May 18 at 05:43

This will give you exact same result as posted on site 

USE WorldEvents
GO

SELECT 
CASE 
WHEN DATEPART(YY,tblEvent.EventDate) like '18%' THEN '19th Century'
WHEN DATEPART(YY,tblEvent.EventDate) like '17%' THEN '18th Century'
WHEN DATEPART(YY,tblEvent.EventDate) like '19%' THEN '20th Century'
WHEN DATEPART(YY,tblEvent.EventDate) like '20%' THEN '21st Century'
END AS Century,COUNT(tblEvent.EventName) AS NumberOfEvents
FROM tblEvent
GROUP BY CUBE(CASE 
WHEN DATEPART(YY,tblEvent.EventDate) like '18%' THEN '19th Century'
WHEN DATEPART(YY,tblEvent.EventDate) like '17%' THEN '18th Century'
WHEN DATEPART(YY,tblEvent.EventDate) like '19%' THEN '20th Century'
WHEN DATEPART(YY,tblEvent.EventDate) like '20%' THEN '21st Century'
END)
ORDER BY NumberOfEvents DESC

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