Question

I am working on a calculated column that will return an “X” if specific criteria are met. The criteria are based pm three columns. The table actually has several columns.

COLUMN1     COLUMN2     COLUMN3     DATE
1234          100         300       1/1/2002
2245          100         500       2/3/2002   
1234          400         400       4/5/2007
2256          100         500       7/5/2010
1234         

The calcucated column will return and x if COLUMN1 has a value of 1234 OR IF COLUMN2 has 2 consecutive values < 200 within a 2 year period or COLUMN3 has 2 consecutive values > 300 within a 2 year period

According to this criteria row 1,3, and 5 will return an X due to the number 1234.
According to Column 2 row 1 will return an X due to the fact that there was a value less then 200 twice in a row within a 2 year period..

Any help would be greatly appreciated….

Answer 1

This might be quite slow on larger volumes of data due to the self join, but should provide you with the data you are looking for…

CREATE TABLE #data
(column1 INT
,column2 INT
,column3 INT
,column4 DATETIME)
INSERT INTO #data 
SELECT 1234         , 100    ,     300     ,'1/1/2002' UNION ALL
SELECT 2245        ,  100    ,     500     ,'2/3/2002'  UNION ALL
SELECT  1234      ,    400   ,      400     ,' 4/5/2007' UNION ALL
SELECT 2256      ,    100    ,     500      ,'7/5/2010' UNION ALL
SELECT 1234     , NULL,NULL,NULL

;with CTE AS
(
SELECT * 
,row_number() OVER (ORDER BY CASE WHEN column4 IS NULL THEN 0 ELSE 1 END DESC) as row
FROM #data
)
SELECT DISTINCT 
c1.row
,c1.column1
,c1.column2
,c1.column3
,c1.column4
,CASE WHEN DATEDIFF(YY,c1.column4,c2.column4) < 2 AND c1.column2 < 200 AND c2.column2 < 200 THEN 'X'
        WHEN c1.column1 = 1234 THEN 'X'
        WHEN DATEDIFF(YY,c1.column4,c2.column4) < 2 AND c1.column3 > 300 AND c2.column3 > 300 THEN 'X' 
        END AS column5
FROM CTE c1
LEFT OUTER JOIN CTE c2
ON c1.row + 1 = c2.row 
ORDER BY c1.row ASC