下面是我的SQL练习：
CREATE TABLE Sales
(
EmpID VARCHAR(10) NOT NULL PRIMARY KEY,
MgrID VARCHAR(10) NOT NULL,
Qty INT NOT NULL
);
INSERT INTO Sales VALUES('A','Z',300);
INSERT INTO Sales VALUES('B','X',100);
INSERT INTO Sales VALUES('C','X',200);
INSERT INTO Sales VALUES('D','Y',200);
INSERT INTO Sales VALUES('E','Z',250);
INSERT INTO Sales VALUES('F','Z',300);
INSERT INTO Sales VALUES('G','X',100);
INSERT INTO Sales VALUES('H','Y',150);
INSERT INTO Sales VALUES('I','X',250);
INSERT INTO Sales VALUES('J','Z',100);
INSERT INTO Sales VALUES('K','Y',250);
select * from dbo.Sales
/* 练习 Row_Number()
select empid,mgrid,qty
,row_number() over(order by qty) as 刘
,row_number() over(order by qty,empid) as 祖
,row_number() over(partition by mgrid order by qty,empid) as 亮
from sales
order by qty
*/
/* 练习 rank()和dense_rank()
select empid,mgrid,qty
,rank() over(order by qty) as rank
,dense_rank() over(order by qty) as dense_rank
,rank() over(partition by mgrid order by qty) as rank_partition
,dense_rank() over(partition by mgrid order by qty) as dense_rank_partition
from sales
order by qty
*/
/* 练习 ntitle()函数
select empid,mgrid,qty
,ntile(3) over(order by qty) as ntile_by_qty
,ntile(3) over(order by qty,empid) as ntile_by_empidqty
,ntile(3) over(partition by mgrid order by qty,empid) as ntile_by_mgrid_empidqty
from sales
order by mgrid,qty
*/
呵呵，写完了。