使用大于和小于比较的搜索 CASE 语句

Question

I have a big calculation which will give numeric values and needs to be compared for greater than and less than

CASE big_expression 
  WHEN > 0 AND <5 THEN 'Less Than 5 Days'
  WHEN > 5 AND <20 THEN 'Between 5 and 20 Days'
  -

Can this be done or I need to use the expressions every time I make a comparison

Answer 1

You can use CTE for the same

        WITH data
         AS (SELECT 1 + 2 + 5 + 9 AS big_exp
             FROM   dual)
    SELECT CASE
             WHEN big_exp > 0
                  AND big_exp < 5 THEN 'Less Than 5 Days'
             WHEN big_exp > 5
                  AND big_exp < 20 THEN 'Between 5 and 20 Days'
             ELSE 'Greater than 20 days'
           END
    FROM   data