Question

We have a database of loyalty card holders. I’m trying to write a simple SQL query that retrieves the full name of a customer based on his card number. However, I specifically need the output to be in the exact order I add the card numbers in. How can I implement this?

Here’s what I did.

SELECT cardnumber, first_name || ' ' || last_name FROM cardholder WHERE
cardnumber LIKE '%1111%' OR
cardnumber LIKE '%2222%' OR
cardnumber LIKE '%3333%'

I should add that I’m not very familiar with SQL, what I know now is pretty much the result of googling this particular problem in the past few days.

Your help is greatly appreciated.

(Also, I would be grateful for a way in which the card numbers can just be pasted into the code as a single block of text, but that’s only bonus.)

Answer 1

SELECT cardnumber, first_name || ' ' || last_name 
FROM (
     SELECT cardnumber, first_name, last_name, c.OrderNo
     FROM cardholder ch, (SELECT '%1111%' cardmask, 1 OrderNo from dual
                        UNION ALL
                        SELECT '%2222%', 2 OrderNo from dual
                        UNION ALL
                        SELECT '%3333%', 3 OrderNo from dual
                        ) c
     WHERE ch.cardnumber LIKE c.cardmask
     Order by c.OrderNo
) t