SQL Tutorial - Nesting CASE statements

Can you think of a more elegant solution?

Why we need to give columns in Group by clause which are using case statements?
Select
c1,
c2='x' sum(values in c3) sum(values in c4) end as 'z'
from table A
where c5='Y' and c6='w'
group by c1, ( Do we need to use c2 here )


c1, Z column (I need Z values grouped by only c1 column )

good video, but not able to clearly hear.

Well done on hitting 1 million total views Bearded Dev. Your channel is pure gold and I wish you were still putting up content

Thank you so much bro

Hi solution and explanation are awesome, need more case with respect to system time concat statement and many more thanks in advance but it's required for further improvement in this case statement.

This was very helpful! Thank you.

In my case statement they provide the conditions for the columns but we need to fetch the values from that column.
E.g. CASE When ABC.(Tbl n).Contact desc= 'phonenumber'.
I want here phonenumbers for different IDs.
How to do this??

Great job with real world problem

Hi, in all your videos you talk about relational set which is basis for relational databases. So in order completely understand the relational set which math should I learn, so that I completely understand the logic behind any given SQL query? Please advice.

On mobile so I cannot elaborate, but this feels like it could benefit from a stored procedure to calculate the discount. I'm thinking about calling a proc in the case statement and feed it the parameters for the different discounts.

WHEN CustomerType
THEN EXEC dbo.CalculateDiscount(...)
END AS Discount