那么为啥不能够动用方面那条 SELECT 语句呢?解释如下:上边的 SELECT
语句钦命了两列。SUM(Order普赖斯卡塔尔 重临八个独门的值,而 Customer 再次来到 6
个值。由此,大家得不到正确的结果。不过,您曾经见到了,GROUP BY
语句化解了这些主题素材。GROUP BY 三个以上的列我们也得以对一个之上的列应用
GROUP BY 语句,就像那样:

SELECT Customer,SUM(Order普赖斯State of Qatar FROM OrdersGROUP BY
Customer结果集相仿那样:

O_Id OrderDate OrderPrice Customer 1 2008/12/29 1000 Bush 2 2008/11/23
1600 Carter 3 2008/10/05 700 Bush 4 2008/09/28 300 Bush 5 2008/08/06
2000 Adams 6 2008/07/21 100 Carter

create table employee(2 ID int,3 name nvarchar (10),4 salary int,5
start_date datetime,6 city nvarchar (10),7 region char (1))8 GO12
insert into employee (ID, name, salary, start_date, city, region)3
values (1, ‘Jason’, 40420, ’02/01/94′, ‘New York’, ‘W’)4 GO

(1 rows affected)1 insert into employee (ID, name, salary,
start_date, city, region)2 values (2, ‘Robert’,14420, ’01/02/95′,
‘Vancouver’,’N’)3 GO

(1 rows affected)1 insert into employee (ID, name, salary,
start_date, city, region)2 values (3, ‘Celia’, 24020, ’12/03/96′,
‘Toronto’, ‘W’)3 GO

(1 rows affected)1 insert into employee (ID, name, salary,
start_date, city, region)2 values (4, ‘Linda’, 40620, ’11/04/97′,
‘New York’, ‘N’)3 GO

(1 rows affected)1 insert into employee (ID, name, salary,
start_date, city, region)2 values (5, ‘David’, 80026, ’10/05/98′,
‘Vancouver’,’W’)3 GO

(1 rows affected)1 insert into employee (ID, name, salary,
start_date, city, region)2 values (6, ‘James’, 70060, ’09/06/99′,
‘Toronto’, ‘N’)3 GO

(1 rows affected)1 insert into employee (ID, name, salary,
start_date, city, region)2 values (7, ‘Alison’,90620, ’08/07/00′,
‘New York’, ‘W’)3 GO

(1 rows affected)1 insert into employee (ID, name, salary,
start_date, city, region)2 values (8, ‘Chris’, 26020, ’07/08/01′,
‘Vancouver’,’N’)3 GO

(1 rows affected)1 insert into employee (ID, name, salary,
start_date, city, region)2 values (9, ‘Mary’, 60020, ’06/09/02′,
‘Toronto’, ‘W’)3 GO

(1 rows affected)12 select * from employee3 GOID name salary
start_date city region———– ———- ———–
———————– ———- —— 1 Jason 40420 1994-02-01
00:00:00.000 New York W 2 Robert 14420 1995-01-02 00:00:00.000
Vancouver N 3 Celia 24020 1996-12-03 00:00:00.000 Toronto W 4 Linda
40620 1997-11-04 00:00:00.000 New York N 5 David 80026 1998-10-05
00:00:00.000 Vancouver W 6 James 70060 1999-09-06 00:00:00.000 Toronto
N 7 Alison 90620 2000-08-07 00:00:00.000 New York W 8 Chris 26020
2001-07-08 00:00:00.000 Vancouver N 9 Mary 60020 2002-06-09
00:00:00.000 Toronto W

(9 rows affected)12 –GROUP BY clause with an aggregator ‘SUM()’.34
SELECT region, SUM(Salary)5 FROM Employee6 WHERE ID BETWEEN 1 AND 107
GROUP BY Region8 GOregion—— ———–N 151120W 295106

(2 rows affected)123 drop table employee4 GO1

协调函数 (举例 SUM卡塔尔 日常需求增加 GROUP BY 语句。GROUP BY 语句GROUP BY
语句用于结合合计函数,依照一个或七个列对结果集举行分组。

近日,大家愿意物色各个客商的总金额。

让大家看一下举个例子省略 GROUP BY 会现身什么样景况:

Customer SUM(OrderPrice) Bush 5700 Carter 5700 Bush 5700 Bush 5700 Adams
5700 Carter 5700

Customer SUM(OrderPrice) Bush 2000 Carter 1700 Adams 2000

SELECT Customer,SUM(OrderPrice卡塔尔 FROM Orders结果集肖似那样:

归纳实例

大家想要使用 GROUP BY 语句对顾客开展结合。

笔者们应用下列 SQL 语句:

地点的结果集不是大家要求的。

很棒吧,对不对?

SELECT Customer,OrderDate,SUM(OrderPrice) FROM OrdersGROUP BY
Customer,OrderDate

SQL GROUP BY 语法SELECT column_name,
aggregate_function(column_name)FROM table_nameWHERE column_name
operator valueGROUP BY column_nameSQL GROUP BY 实例大家具有下边那么些Orders 表:

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