mssql表函数中的条件判断怎么写？

create FUNCTION [dbo].[p] ( @c real )
RETURNS TABLE
AS
RETURN
(
if @c=1
select * from tab where a-b>0
else
select * from tab where a-b<0
)

应该这样吧
CREATE FUNCTION [dbo].[p] (@c REAL)
RETURNS @tempTable TABLE([ID] INT, [NAME] VARCHAr(50), a int, b int)
AS
BEGIN
IF @c = 1
INSERT INTO @tempTable
SELECt * FROM TAB WHERe a - b > 0
ELSE
INSERT INTO @tempTable
SELECt * FROM TAB WHERe a - b < 0
RETURN
END

update table set a=floor(a) update table set a=round(a,0)