SQL | Calculations exercise | With no help offered, list events with interesting letters!

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Software ==> SQL  (198 exercises)
Version ==> Any version of SQL Server
Topic ==> Calculations  (7 exercises)
Level ==> Harder than average
Courses ==> Introduction to SQL  /  Fast-track SQL
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If you've reached this point, you're probably ready for a challenge.  See if you can write a query to list out all of the non-boring events:

Non-boring events

The first few of the 28 events you should see.

As the above query shows, a boring event is one which doesn't begin and end with the same letter, and which doesn't begin and end with a vowel!

If you get this working, you could always show that there aren't any ultra-interesting events (ones which begin and end in a vowel).

Save this query as Boring events, then close it down.

This page has 3 threads Add post
SeahawkZim   Reply to SeahawkZimReply
25 Nov 19 at 02:48

I added in the default of "Boring event" but this can be left out.

select EventName, case when left(eventname, 1) = right(eventname, 1) then 'Same letter'
                       when left(eventname, 1) like '[aeiou]' and right(eventname, 1) like '[aeiou]' then 'Begins and ends with a vowel'
                       else 'Boring event' end as Verdict
from tblevent
order by Verdict

Habeshawiw2T   Reply to Habeshawiw2TReply
12 Mar 19 at 15:13

SELECT * FROM (
SELECT EventName
        , CASE
            WHEN LOWER(LEFT(EventName,1)) IN ('a','e','i','o','u') AND LOWER(RIGHT(EventName,1)) IN ('a','e','i','o','u')
                THEN 'Begins and ends with vowle'
            WHEN LOWER(LEFT(EventName,1)) = LOWER(RIGHT(EventName,1))
                THEN 'Same letter'
          END AS Verdict
FROM tblEvent ) AS T
WHERE Verdict IS NOT NULL
 

hjay629   Reply to hjay629Reply
19 Feb 19 at 01:01

NOTE: The QUESTION IS ORDERD BY EVENTDATE, if anyone was wondering the order.

If anyone could verify if this is correct, because it seem uncomfortably long:

SELECT
EventName,
CASE
    WHEN LEFT(EventName, 1) = RIGHT(EventName, 1) 
        THEN 'Same letter'
    WHEN (LEFT(EventName, 1) = 'a'  OR LEFT(EventName, 1) = 'e' OR LEFT(EventName, 1) = 'i' OR LEFT(EventName, 1) = 'o' OR LEFT(EventName, 1) = 'u') AND (RIGHT(EventName, 1) = 'a' OR RIGHT(EventName, 1) = 'e' OR RIGHT(EventName, 1) = 'i' OR RIGHT(EventName, 1) = 'o' OR RIGHT(EventName, 1) = 'u') 
        THEN 'Begins and ends with vowel' 
        
    END as 'Verdict' 


FROM
tblEvent
WHERE (CASE
    WHEN LEFT(EventName, 1) = RIGHT(EventName, 1) 
        THEN 'Same letter'
    WHEN (LEFT(EventName, 1) = 'a'  OR LEFT(EventName, 1) = 'e' OR LEFT(EventName, 1) = 'i' OR LEFT(EventName, 1) = 'o' OR LEFT(EventName, 1) = 'u') AND (RIGHT(EventName, 1) = 'a' OR RIGHT(EventName, 1) = 'e' OR RIGHT(EventName, 1) = 'i' OR RIGHT(EventName, 1) = 'o' OR RIGHT(EventName, 1) = 'u') 
        THEN 'Begins and ends with vowel' 
        
    END ) IS NOT NULL

ORDER BY
EventDate

tmccarthygcu   Reply to tmccarthygcuReply
06 Mar 19 at 20:08

Two ways to minimize the code. Firstly use an IN statement to have it group the sections without all those OR statements. To remove the lengthy WHERE clause, simply wrap up the SELECT in parens and name the result, then select all values from the result and do a WHERE on there, as seen here:

USE WorldEvents

SELECT t.* FROM (SELECT EventName,
        CASE WHEN LEFT(EventName, 1) = RIGHT(EventName, 1)
            THEN 'Same Letter'
            WHEN LEFT(EventName, 1) IN ('a', 'e', 'i', 'o', 'u') AND RIGHT(EventName, 1) IN ('a', 'e', 'i', 'o', 'u')
            THEN 'First letter vowel'
        END AS 'Result'
        FROM tblEvent) t
    WHERE t.Result IS NOT NULL

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