MSSQL_How to show number's range by a loop? - sql-server

Question

I am using MSSQL to run a query, however I want to simply my current steps by using a loop.
-- My current script
select product, price,price_range
from
(select
product,
price,
case
when price <= 100 then 'upto100'
when price between 101 and 200 then '101-200'
when price between 201 and 300 then '201-300'
when price between 301 and 400 then '301-400'
when price between 401 and 500 then '401-500'
when price between 501 and 600 then '501-600'
when price between 601 and 700 then '601-700'
when price between 701 and 800 then '701-800'
when price >= 801 then '800+EURO'
end as price_range
from DATA) as A
Now my script works, it returns me correct result as I wanted:
product price price_range
shoes 50 upto100
clothes 456 401-500
computer 1500 800+EURO
BUT, can I make it simple? Can I somehow use loops instead of 'case...when...then'? Then if segments of price increase, I don't have to write lots of 'case..'.
I tried to use 'declare' and 'while' but didn't get it worked. How to set variable for loops in this case?

Answer 1

You can't get much simpler than that. The only thing neater would be to create a table with the price ranges and to join against it instead of hard-coding it in the query. You should do that if this query is used in multiple places, or rather often.
Something like:
CREATE TABLE price_ranges (
lowest INT,
highest INT,
name VARCHAR
)
INSERT INTO price_ranges VALUES (
(NULL, 100, 'upto100'),
(101, 201, '101-200),
...
(801, NULL, '801+EURO')
)
SELECT DATA.product, DATA.price, RANGES.name AS price_range
FROM DATA,
price_ranges RANGES
WHERE (DATA.price >= RANGES.lowest OR RANGES.lowest IS NULL)
AND (DATA.price <= RANGES.highest OR RANGES.highest IS NULL)
AS A