Question

I have a table with the following values:

Value
0
1.2
1.3
1.4
0
1.2
1.3
1.4

From the above data, I need to sum the 2 highest number after the set is reset to 0, thus coming to the total of 2.8.

If I could get row_number() to restart every time there is a 0, that would be perfect, however it doesn’t offer such functionality.

Thanks.

Answer 1

DECLARE @your_table TABLE (id INT,value FLOAT) 

INSERT INTO @your_table
SELECT 1,0 UNION ALL
SELECT 2,1.2 UNION ALL
SELECT 3,1.3 UNION ALL
SELECT 4,1.4 UNION ALL
SELECT 5,0 UNION ALL
SELECT 6,1.2 UNION ALL
SELECT 7,1.3 UNION ALL
SELECT 8,1.4


;WITH T AS
(
SELECT 
   ROW_NUMBER() OVER (PARTITION BY CASE WHEN value = 0 THEN 0 ELSE 1 END ORDER BY id)-
   ROW_NUMBER() OVER (ORDER BY id ) AS Grp
,id,value
FROM @your_table
), T2 AS
(
SELECT MAX(value) AS value
FROM T
WHERE value<>0
GROUP BY Grp)
SELECT SUM(value)
FROM T2