SET @dayx= '2004/02/1'
set @nextm=DATEADD(d,31,@dayx)
SET @begind=convert(varchar,year(@dayx))+'/'+convert(varchar,month(@dayx))
+'/'+'01'
SET @endd=convert(varchar,year(@nextm))+'/'+convert(varchar,month(@nextm))
+'/'+'01'
CREATE FUNCTION 返回月天数(@YY CHAR(4), @MM CHAR(2))
RETURNS INT
AS
BEGIN
DECLARE @Riqi DATETIME,@I INT
SET @MM=CONVERT(CHAR(2),CONVERT(INT,@MM)+1)
SET @Riqi = dateadd(day,-1,CONVERT(DATETIME,@YY+'-'+@MM+'-01'))
SET @I =CAST(datepart(day,@Riqi) AS INT)
return @I
END