Question

This question is a continuation of the same effort to code my first cte that I mentioned in a couple other recent posts. In a nutshell, I’m working through a couple compiler errors for the query below. I’m now getting the error “Subquery returned more than one value. This is not permitted when the subquery follows =, !=, <, <=, >, >= or when the subquery is used as an expression.” But what I’ve come up with below seems “legal” to me based on my current abilities… any help would be great. BTW I either get that error, or Visual Studio 2010 shuts down when I try to run this…

WITH Symb AS
(
     SELECT Symbol
     FROM tblSymbolsMain
),

DatesNotNeeded AS
(
     SELECT Date
     FROM tblDailyPricingAndVol inner join Symb on
         tblDailyPricingAndVol.Symbol = Symb.Symbol
),

WideDateRange AS
(
     SELECT TradingDate
     FROM tblTradingDays
     WHERE (TradingDate >= dbo.NextAvailableDataDownloadDateTime()) AND (TradingDate <= dbo.LatestAvailableDataDownloadDateTime())
),

DatesNeeded AS
(
     SELECT TradingDate
     FROM WideDateRange wdr
     WHERE NOT EXISTS (SELECT * FROM DatesNotNeeded d where d.Date = wdr.TradingDate)
)

SELECT Symb.Symbol, DatesNeeded.TradingDate
FROM Symb CROSS JOIN DatesNeeded

And my functions, as requested:

ALTER FUNCTION dbo.LatestAvailableDataDownloadDateTime()
    RETURNS date
BEGIN
    RETURN (SELECT DATEADD(hour, 18, MAX(TradingDate)) AS LatestTradingDateAvailForDL 
    FROM tblTradingDays
    GROUP BY TradingDate
    HAVING (DATEADD(hour, 18, MAX(TradingDate)) < GETDATE()))
END

ALTER FUNCTION dbo.NextAvailableDataDownloadDateTime()
    RETURNS date
BEGIN
    RETURN (SELECT DATEADD(hour, 18, MIN(TradingDate)) AS TrDate
    FROM tblTradingDays
    HAVING (DATEADD(hour, 18, MIN(TradingDate)) > dbo.LatestDataDownloadDate()))
END

Answer 1

Your functions are returning more than one value. Try this:

ALTER FUNCTION dbo.LatestAvailableDataDownloadDateTime()
    RETURNS date
BEGIN
    RETURN (SELECT DATEADD(hour, 18, MAX(TradingDate)) AS LatestTradingDateAvailForDL 
    FROM tblTradingDays
    WHERE (DATEADD(hour, 18, TradingDate) < GETDATE()))
END

And:

ALTER FUNCTION dbo.NextAvailableDataDownloadDateTime()
    RETURNS date
BEGIN
    RETURN (SELECT DATEADD(hour, 18, MIN(TradingDate)) AS TrDate
    FROM tblTradingDays
    WHERE (DATEADD(hour, 18, TradingDate) > dbo.LatestDataDownloadDate()))
END