用实例展示left Join,right join,inner join,join,cross join,union 的区别
1.向TI,T2插入数据：
T1 7条
ID Field2 Field3 Field4
1 1 3 54
2 1 3 54
3 1 3 54
4 2 3 54
5 3 3 54
6 4 3 54
7 5 3 54
T2 7条
IDField22Field23
1133
2133
3133
4133
5233
6333
7 9 33
2.测试left join
select ROW_NUMBER()over (order by t1.id,t2.id) as row_num,* from dbo.T1 left join dbo.T2 on t1.Field2=t2.Field22
row_numIDField2Field3Field4IDField22Field23
1113541133
2113542133
3113543133
4113544133
5213541133
6213542133
7213543133
8213544133
9313541133
10313542133
11313543133
12313544133
13423545233
14533546333
NULLNULLNULL
NULLNULLNULL
3.测试right join
select ROW_NUMBER()over (order by t1.id,t2.id) as row_num,* from dbo.T1 right join dbo.T2 on t1.Field2=t2.Field22
row_numIDField2Field3Field4IDField22Field23
2113541133
3113542133
4113543133
5113544133
6213541133
7213542133
8213543133
9213544133
10313541133
11313542133
12313543133
13313544133
14423545233
15533546333
4.测试join
select ROW_NUMBER()over (order by t1.id,t2.id) as row_num,* from dbo.T1 join dbo.T2 on t1.Field2=t2.Field22
row_numIDField2Field3Field4IDField22Field23
1113541133
2113542133
3113543133
4113544133
5213541133
6213542133
7213543133
8213544133
9313541133
10313542133
11313543133
12313544133
13423545233
14533546333
5.测试inner join
select ROW_NUMBER()over (order by t1.id,t2.id) as row_num,* from dbo.T1 inner join dbo.T2 on t1.Field2=t2.Field22
row_numIDField2Field3Field4IDField22Field23
1113541133
2113542133
3113543133
4113544133
5213541133
6213542133
7213543133
8213544133
9313541133
10313542133
11313543133
12313544133
13423545233
14533546333
6.测试cross join
select ROW_NUMBER()over (order by t1.id,t2.id) as row_num,* from dbo.T1 cross join dbo.T2 on t1.Field2=t2.Field22
消息156，级别15，状态1，第1 行
关键字'on' 附近有语法错误。
select ROW_NUMBER()over (order by t1.id,t2.id) as row_num,* from dbo.T1 cross join dbo.T2
row_numIDField2Field3Field4IDField22Field23
1113541133
2113542133
3113543133
4113544133
5113545233
6113546333
7113548933
8213541133
9213542133
10213543133
11213544133
12213545233
13213546333
14213548933
15313541133
16313542133
17313543133
18313544133
19313545233
20313546333
21313548933
22423541133
23423542133
24423543133
25423544133
26423545233
27423546333
28423548933
29533541133
30533542133
31533543133
32533544133
33533545233
34533546333
35533548933
36643541133
37643542133
38643543133
39643544133
40643545233
41643546333
42643548933
43753541133
44753542133
45753543133
46753544133
47753545233
48753546333
49753548933
7.测试unoin
select * from dbo.T1 union all select * from dbo.T2
消息205，级别16，状态1，第1 行
使用UNION、INTERSECT 或EXCEPT 运算符合并的所有查询必须在其目标列表中有相同数目的表达式。
select Field2 from dbo.T1 union all select Field22 from dbo.T2
Field2
1
1
1
2
3
4
5
1
1
1
1
2
3
9
with T3 as
( select Field2 from dbo.T1 union all select Field22 from dbo.T2 )
select ROW_NUMBER() over (order by T3.field2) as row_num,* from T3
row_numField2
11
21
31
41
51
61
71
82
92
103
113
124
135
149
8.生成数据库的脚本
USE [Demo]
GO
/****** Object: Table [dbo].[T1] Script Date: 09/27/2013 23:19:29 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[T1](
) NOT NULL,
[Field2] [int] NULL,
[Field3] [int] NULL,
[Field4] [int] NULL,
CONSTRAINT [PK_T1] PRIMARY KEY CLUSTERED
(
[ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
USE [Demo]
GO
/****** Object: Table [dbo].[T2] Script Date: 09/27/2013 23:19:53 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[T2](
) NOT NULL,
[Field22] [int] NOT NULL,
[Field23] [int] NOT NULL,
CONSTRAINT [PK_T2] PRIMARY KEY CLUSTERED
(
[ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
delete from dbo.T1
truncate table dbo.T2
select * from T1
select * from T2
)
)
)
)
)
)
)
truncate table dbo.T2
)
)
)
)
)
)
)
)
select ROW_NUMBER()over (order by t1.id,t2.id) as row_num,* from dbo.T1 left join dbo.T2 on t1.Field2=t2.Field22
select ROW_NUMBER()over (order by t1.id,t2.id) as row_num,* from dbo.T1 right join dbo.T2 on t1.Field2=t2.Field22
select ROW_NUMBER()over (order by t1.id,t2.id) as row_num,* from dbo.T1 join dbo.T2 on t1.Field2=t2.Field22
select ROW_NUMBER()over (order by t1.id,t2.id) as row_num,* from dbo.T1 inner join dbo.T2 on t1.Field2=t2.Field22
select ROW_NUMBER()over (order by t1.id,t2.id) as row_num,* from dbo.T1 cross join dbo.T2 on t1.Field2=t2.Field22
select ROW_NUMBER()over (order by t1.id,t2.id) as row_num,* from dbo.T1 cross join dbo.T2
select * from dbo.T1 union all select * from dbo.T2
select Field2 from dbo.T1 union all select Field22 from dbo.T2
with T3 as
( select Field2 from dbo.T1 union all select Field22 from dbo.T2 )
select ROW_NUMBER() over (order by T3.field2) as row_num,* from T3
用实例展示left Join,right join,inner join,join,cross join,union 的区别的更多相关文章
- T-SQL 中的CROSS JOIN用法（半翻译）
突然发现个很吊的链接,我们来看看学习数据库要做些什么,胆小慎点:DBA工作内容!!!! 今天来翻译一篇关于T-SQL的文章,本文可供微软认证70-461:QueryingMicrosoft SQL S ...
- 高级T-SQL进阶系列 （一）【下篇】：使用 CROSS JOIN 介绍高级T-SQL
[译注:此文为翻译,由于本人水平所限,疏漏在所难免,欢迎探讨指正] 原文链接:传送门. 性能考虑产生了笛卡尔积的这个CROSS JOIN操作符具有一些性能方面的问题需要考虑.因为SQL引擎需要将一个数 ...
- SQL CROSS JOIN
最近在讲到T-SQL查询的Join部分时,一下子没有想起来CROSS JOIN的用法,因为其实平常也确实基本不用到.特意找了一个例子,以供参考 CROSS JOIN又称为笛卡尔乘积,实际上是把两个表乘 ...
- CROSS JOIN
原文:CROSS JOIN 最近在讲到T-SQL查询的Join部分时,一下子没有想起来CROSS JOIN的用法,因为其实平常也确实基本不用到.特意找了一个例子,以供参考 CROSS JOIN又称为笛 ...
- MySQL应用之CROSS JOIN用法简介教程
目录 2. cross join用法 @ 本博客翻译自两篇博客的: http://www.mysqltutorial.org/mysql-cross-join/ https://www.w3resou ...
- 通俗易懂的join、left join、right join、full join、cross join
内连接:列出与连接条件匹配的数据行(join\inner join) 外连接:两表合并,如有不相同的列,另外一个表显示null(left join\right join\full outer join ...
- 内连接、左外连接、右外连接、全外连接、交叉连接（CROSS JOIN）-----小知识解决大数据攻略
早就听说了内连接与外连接,以前视图中使用过.这次自考也学习了,只是简单理解,现在深入探究学习(由于上篇博客的出现)与实践: 概念 关键字: 左右连接 数据表的连接有: 1.内连接(自然连接): 只有两 ...
- 【数据库】left join（左关联）、right join（右关联）、inner join（自关联）的区别
left join(左关联).right join(右关联).inner join(自关联)的区别 用一张图说明三者的区别: 总结: left join(左联接) 返回包括左表中的所有记录和右表中关联 ...
- Python之路(第四十二篇)线程相关的其他方法、join()、Thread类的start()和run()方法的区别、守护线程
一.线程相关的其他方法 Thread实例对象的方法 # isAlive(): 返回线程是否活动的. # getName(): 返回线程名. # setName(): 设置线程名. threadin ...
随机推荐
- POJ 1068 Parencodings
Parencodings Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 24932 Accepted: 14695 De ...
- Android中利用画图类和线程画出闪烁的心形
本文讲解主要涉及的知识点: 1.线程控制 2.画图类 3.心形函数 大家先看图片: <ig ...
- Spring分布式事务实现
分布式事务是指操作多个数据库之间的事务,spring的org.springframework.transaction.jta.JtaTransactionManager,提供了分布式事务支持.如果使用 ...
- Windows下Qt开发环境:OpenGL导入3DMax模型(.3DS)
参考:http://blog.csdn.net/cq361106306/article/details/41876541 效果: 源代码: 解释: CLoad3DS.h为加载3DMax模型的头文件,C ...
- 【Windows核心编程】重载类成员函数new / new[] / delete / delete[]
// Heap.cpp : 定义控制台应用程序的入口点. // #include "stdafx.h" #include <Windows.h> #include &l ...
- CSS基础知识——选择器
选择器 元素选择器# 文档元素为最基本的选择器 例子:div{属性:值}; 选择器分组 例子:h2,p{属性:值}; 表示符合这两种规则的元素设置相同的属性值 通配选择器 表示所有元素 类选择器 应用 ...
- [HIve - LanguageManual] Join Optimization (不懂)
Join Optimization Join Optimization Improvements to the Hive Optimizer Star Join Optimization Star S ...
- scanf,sscanf利用format跳过干扰的空格
scanf,sscanf利用format跳过干扰的空格 用了一点时间做读取配置部分的代码,希望一次记录上读取N个数据, 希望读取的格式就是一个IP地址加上端口号,希望把IP地址读取到4个短整数里面,端 ...
- Spark SQL概念学习系列之如何使用 Spark SQL（六）
val sqlContext = new org.apache.spark.sql.SQLContext(sc) // 在这里引入 sqlContext 下所有的方法就可以直接用 sql 方法进行查询 ...
- CentOS查看系统信息-CentOS查看命令
一:查看cpu more /proc/cpuinfo | grep "model name" grep "model name" /proc/cpuinfo 如 ...