效率问题
select top 3 * from all_data where id not in (select top 2 id from all_data order by id) order by id
和
DECLARE @BEGINROW INT,@ENDROW INT,@COUNTS INT,@COUNTS1 INT
SET @BEGINROW=300
SET @ENDROW=40
SELECT @COUNTS=@ENDROW-@BEGINROW+1
SELECT @COUNTS1=@BEGINROW-1
EXEC('SELECT TOP '+@COUNTS+
' * FROM all_data WHERE ID NOT IN (SELECT TOP '+@COUNTS1+' ID FROM all_data)')
为什么上句明显比下句慢很多