Setting the max and min bounds of a result set

Question

I'm trying to set the upper and lower bound values of a result set. Meaning, I want to limit the values in my result set to not be below/above a certain number, BUT I want any number in my result set that is below/above the lower/upper bound that i have designated to be decoded to the lower/upper bound number that I have designated. Here's an example to help clarify:
WITH temp_table AS
SELECT 1231.12 AS col FROM dual UNION ALL
SELECT 1001.00 FROM dual UNION ALL
SELECT -32.0 FROM dual UNION ALL
SELECT -3.0 FROM dual UNION ALL
SELECT 332.0 FROM dual UNION ALL
SELECT 211.0 FROM dual
SELECT CASE WHEN col < 0 -- 0 is the lower bound
            THEN
                 0
            WHEN col > 1000 -- 1000 is the upper bound
            THEN
                 1000
            ELSE
                 col
       END as desired_result
FROM   temp_tabledesired result set:
        DESIRED_RESULT
     1000
     1000     
        0
     0
     332
     211I was wondering if there was another function or method of achieving my desired result set without having to use a CASE statement? I have to do this to several columns, and it doesn't seem very efficient to throw a CASE statement around each one.

Answer 1

LEAST and GREATEST will do that too :
SQL> WITH temp_table AS
  2  (
  3   SELECT 1231.12 AS col FROM dual UNION ALL
  4   SELECT 1001.00 FROM dual UNION ALL
  5   SELECT -32.0 FROM dual UNION ALL
  6   SELECT -3.0 FROM dual UNION ALL
  7   SELECT 332.0 FROM dual UNION ALL
  8   SELECT 211.0 FROM dual
  9   )
10  SELECT least(greatest(col, 0), 1000)
11  FROM temp_table
12  ;
LEAST(GREATEST(COL,0),1000)
                       1000
                       1000
                          0
                          0
                        332
                        211
6 rows selected
I have to do this to several columns, and it doesn't seem very efficient to throw a CASE statement around each one.Any test case showing CASE as not efficient?
Edited by: odie_63 on 25 juil. 2012 23:20