Doing an Update in SQL, with a CASE WHEN Statement - sql-server-2008

Question

What I want to know, is it somehow possible to do an update to a table, in a Case statement? Or if there is Some way to do this? I have a button to pull a report (this button goes and calls a stored procedure, and it gets a list of columns and their residing columns).
I basically want to update the table, IF, and only IF, the DateClosed column is NULL AND ClosedBy is null (i.e., the end date was reached, so the campaign is CLOSED).
The way I usually determine if the campaign is closed, is by doing Checks on the start and end date. Ie When EndDate < GetDate() Then "Closed". So obviously that displays correctly, but my database displays null because there was no update.
This is my stored procedure:
ALTER PROCEDURE [dbo].[sp_CampaignStats]
#from DATETIME,
#to DATETIME
AS
SELECT
CampaignName AS 'CAMPAIGN NAME',
CampaignDescription AS 'CAMPAIGN DESCRIPTION',
CASE
WHEN EndDate >= GETDATE() AND StartDate <= GETDATE() THEN 'Active'
WHEN StartDate >= GETDATE() THEN 'Pending'
WHEN CampaignStatus = 4 THEN 'Archived'
ELSE 'Closed'
END as 'CurrentStatus',
CONVERT(VARCHAR(11), StartDate, 106) + ' - ' + CONVERT(VARCHAR(11), EndDate, 106) AS 'CAMPAIGN DATES',
Discount AS 'DISCOUNT',
[Target] AS 'TARGET',
Uptake AS 'UPTAKE',
tc.DateAdded as 'DATE ADDED',
U.FirstName + ' ' + u.LastName As 'ADDED BY',
CASE
WHEN CloseBy IS NULL AND EndDate < GETDATE() AND CloseBy = Null THEN 'System'
WHEN CampaignStatus = 4 THEN 'Archived'
WHEN CloseBy IS not Null THEN UU.FirstName + ' ' + uu.LastName
ELSE 'Not Closed'
END AS 'CLOSED BY',
DateClosed AS 'DATE CLOSED'
FROM
Tbl_Campaign tc
LEFT JOIN
tbl_User U ON Tc.AddedBy = U.UserId
LEFT JOIN
Tbl_User UU ON TC.CloseBy = UU.UserId
WHERE
(startDate >= #from OR enddate <= #to)
AND CampaignStatus IN (1, 2, 3, 4)

Answer 1

So you want to update your table before the SELECT happens?
Try something like this:
UPDATE dbo.Tbl_Campaign
SET -- what do you want to update to what value here????
WHERE
DateClosed IS NULL
AND ClosedBy IS NULL
Or what exactly are you trying to do?? You're still being rather unclear and vague in your question - you're not mentioning WHAT column in WHICH table you want to update to WHAT value if that condition is met.....

Answer 2

SQL only allows one operation per statement. SELECTs only read data, UPDATEs only write data.
If I've understood your problem though, you've got a NULL in an end date field that's preventing you from displaying your button correctly? If that's the case, you could do something like
SELECT
StatusDate =
CASE WHEN EndDate < GETDATE() THEN 'Closed'
WHEN EndDate > GETDATE() THEN 'Open'
WHEN EndDate IS NULL THEN 'End Date not set'
END
FROM
SourceTable
Or, if it was easier in your code, wrap the CASE in an ISNULL or COALESCE function that can be used to fill in the default value.
None of these will update the table on the read, but they'll all stop the NULL from preventing your read returning anything at all.
Seeing your actual code now, what you want is something like this -
ALTER PROCEDURE [dbo].[usp_CampaignStats]
#from DATETIME,
#to DATETIME
AS
SET NOCOUNT ON;
--Make sure any NULLs we need to have been cleaned up
UPDATE Tbl_Campaign
SET <Fields>
WHERE DateClosed IS NULL AND ClosedBy IS NULL
AND (startDate >= #from OR enddate <= #to)
AND CampaignStatus IN (1, 2, 3, 4);
--Now return the data
SELECT
CampaignName AS 'CAMPAIGN NAME',
CampaignDescription AS 'CAMPAIGN DESCRIPTION',
CASE
WHEN EndDate >= GETDATE() AND StartDate <= GETDATE() THEN 'Active'
WHEN StartDate >= GETDATE() THEN 'Pending'
WHEN CampaignStatus = 4 THEN 'Archived'
ELSE 'Closed'
END as 'CurrentStatus',
CONVERT(VARCHAR(11), StartDate, 106) + ' - ' + CONVERT(VARCHAR(11), EndDate, 106) AS 'CAMPAIGN DATES',
Discount AS 'DISCOUNT',
[Target] AS 'TARGET',
Uptake AS 'UPTAKE',
tc.DateAdded as 'DATE ADDED',
U.FirstName + ' ' + u.LastName As 'ADDED BY',
CASE
WHEN CloseBy IS NULL AND EndDate < GETDATE() AND CloseBy = Null THEN 'System'
WHEN CampaignStatus = 4 THEN 'Archived'
WHEN CloseBy IS not Null THEN UU.FirstName + ' ' + uu.LastName
ELSE 'Not Closed'
END AS 'CLOSED BY',
DateClosed AS 'DATE CLOSED'
FROM
Tbl_Campaign tc
LEFT JOIN
tbl_User U ON Tc.AddedBy = U.UserId
LEFT JOIN
Tbl_User UU ON TC.CloseBy = UU.UserId
WHERE
(startDate >= #from OR enddate <= #to)
AND CampaignStatus IN (1, 2, 3, 4);