尝试使用此代码。

Try with this code.

(select case when P.Factor1=' ' then 0
else P.Factor1
 end
from pr.PODTL P where FkItemCode=D.FkItemCode and DocCode=@ParentDocCode) as ***erageAmt

EG

E.G.

DECLARE @compareprice money, @cost money 
EXECUTE Production.uspGetList '%Bikes%', 700, 
    @compareprice OUT, 
    @cost OUTPUT
IF @cost <= @compareprice 
BEGIN
    PRINT 'These products can be purchased for less than

' + RTRIM（CAST（ @ compareprice AS varchar （ 20 ）））+ ' 。'
END
ELSE
PRINT ' 此类别中所有产品的价格超过

'+RTRIM(CAST(@compareprice AS varchar(20)))+'.' END ELSE PRINT 'The prices for all products in this category exceed