幾條簡單而實用的SQL語句

幾條簡單而且實用的SQL語言：

1. 選出每X-Y條記錄(按某個條件排序)

select top (y-x) * from (select top y * from table order by id) a order by id desc

2. 先出符合打件的記錄數

select conunt(*) from table where

3. 選取最大ID號

select max(ID) from table

select top 1 id from table order by id desc

4. 按字段1統計字段2

select count(字段2) from table group by 字段1

select sum(字段2) from table group by 字段1

5. 選取不重復記錄

select distinct 字段 from table