I have a stored procedure as follows:
CREATE PROC [dbo].[Incidents]
(@SiteName varchar(200))
AS
SELECT
(
SELECT SUM(i.Logged)
FROM tbl_Sites s
The easiest, and most readable, way I've found to accomplish this is through:
CREATE PROC [dbo].[Incidents]
(@SiteName varchar(200))
AS
SELECT SUM(COALESCE(i.Logged, 0)) AS LoggedIncidents
FROM tbl_Sites s
INNER JOIN tbl_Incidents i
ON s.Location = i.Location
WHERE s.Sites = @SiteName
AND i.[month] = DATEADD(mm, DATEDIFF(mm, 0, GetDate()) -1,0)
GROUP BY s.Sites
Put it outside:
SELECT COALESCE(
(
SELECT SUM(i.Logged)
FROM tbl_Sites s
INNER JOIN tbl_Incidents i
ON s.Location = i.Location
WHERE s.Sites = @SiteName AND i.[month] = DATEADD(mm, DATEDIFF(mm, 0, GetDate()) -1,0)
GROUP BY s.Sites
), 0) AS LoggedIncidents
If you are returning multiple rows, change INNER JOIN to LEFT JOIN
SELECT COALESCE(SUM(i.Logged),0)
FROM tbl_Sites s
LEFT JOIN tbl_Incidents i
ON s.Location = i.Location
WHERE s.Sites = @SiteName AND i.[month] = DATEADD(mm, DATEDIFF(mm, 0, GetDate()) -1,0)
GROUP BY s.Sites
By the way, don't put any function or expression inside aggregate functions if it's not warranted, e.g. don't put ISNULL, COALESCE inside of SUM, using function/expression inside aggregation cripples performance, the query will be executed with table scan
You could wrap the SELECT in another SELECT like so:
CREATE PROC [dbo].[Incidents]
(@SiteName varchar(200))
AS
SELECT COALESCE(TotalIncidents ,0)
FROM (
SELECT
(
SELECT SUM(i.Logged) as TotalIncidents
FROM tbl_Sites s
INNER JOIN tbl_Incidents i
ON s.Location = i.Location
WHERE s.Sites = @SiteName AND i.[month] = DATEADD(mm, DATEDIFF(mm, 0, GetDate()) -1,0)
GROUP BY s.Sites
) AS LoggedIncidents
)
Just ran into this problem, Kirtan's solution worked for me well, but the syntax was a little off. I did like this:
ISNULL(SUM(c.Logged), 0)
Post helped me solve my problem though so thanks to all.
You'll have to use ISNULL
like this -
ISNULL(SUM(c.Logged), 0)
Or, as Michael said, you can use a Left Outer Join.
I encountered this problem in Oracle.
Oracle does not have an ISNULL()
function. However, we can use the NVL()
function to achieve the same result:
NVL(SUM(c.Logged), 0)