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Software ==>	SQL (203 exercises)
Topic ==>	Aggregation and grouping (12 exercises)
Level ==>	Harder than average
Subject ==>	SQL training

Combine CAST, AVG, COUNT, LEN, UPPER and LEFT to show the average length of event names by category initial

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.

Before you can do this exercise, you'll need to download and unzip this file . Once you've done this:

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).

Create a query which shows two statistics for each category initial:

The number of events for categories beginning with this letter; and
The average length in characters of the event name for categories beginning with this letter.

Here are the first few rows you should get when you run your ever-so-slightly contrived query:

It looks like most events begin with categories beginning with an E (there are 5 such categories, which helps), but that Ns have it for the longest average event name length.

You'll need to use the following functions at some point: CAST or CONVERT, AVG, COUNT, LEN, UPPER and LEFT!

Save this query as P please bob, then close it down.

You can unzip this file to see the answers to this exercise, although please remember this is for your personal use only.

You can find other training resources for the subject of this exercise here:

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From:	Bhavya59
When:	01 Aug 24 at 13:36

SELECT SUBSTRING(CategoryName, 1, 1) AS CategoryInitial

,COUNT(EventID) AS 'No of Events'

,AVG(CAST(LEN(EventName) AS DECIMAL(5,2))) 'Avg event name length'

FROM tblEvent e

INNER JOIN tblCategory c ON e.CategoryID=c.CategoryID

GROUP BY SUBSTRING(CategoryName, 1, 1)

From:	Rupchand7
When:	14 Nov 23 at 06:44

select left(categoryname,1) as [Category initial], count(eventid) as [Number of events],
cast(avg(cast(len(eventname) as float)) as decimal(5,2)) as [Average event name length] from tblCategory join tblEvent on
tblCategory.CategoryID = tblEvent.CategoryID group by left(categoryname,1)

From:	Yash2211
When:	03 Oct 23 at 16:36

select

left(tc.categoryname,1) as [Category intial],
count(te.eventid) as [No of Events],
cast(avg(cast(len(te.eventname) as float)) as decimal(6,2)) as [Average event name length]

from tblevent as te
inner join tblCategory tc on te.CategoryID=tc.CategoryID
group by left(tc.categoryname,1)

From:	FloridaMan
When:	24 Sep 21 at 15:52

select
   left (c.CategoryName ,1) as Category_Initial
       , count (e.EventName) as Number_of_Events
       , sum(len (e.EventName)) as Total_Length
       , cast(avg( cast( len (e.EventName) as float ) ) as decimal(6,2) ) as AVG_Event_Name_Length
       from [dbo].[tblEvent] e
       left join [dbo].[tblCategory] c
       on e.CategoryID = c.CategoryID

group by left (c.CategoryName ,1)

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EXERCISE TOPIC

SQL EXERCISES

SQL EXERCISES

Combine CAST, AVG, COUNT, LEN, UPPER and LEFT to show the average length of event names by category initial

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