使用连接
SQL 1999
SELECT table1.column, table2.column
FROM table1
[NATURAL JOIN table2] |
[JOIN table2 USING (column_name)] |
[JOIN table2
ON (table1.column_name = table2.column_name)]|
[LEFT|RIGHT|FULL OUTER JOIN table2
ON (table1.column_name = table2.column_name)]|
[CROSS JOIN table2];

自然连接:
SELECT department_id, department_name, location_id, city
FROM departments NATURAL JOIN locations ;

select department_id, department_name,department.location_id, city
from departments, locations
where departments.location_id = locations.location_id

create table t1(c1 number, c2 number, c3 number, c4 number);
create table t2(c1 number, c2 number, c3 number);
insert into t1 values(1,1,1,1);
insert into t1 values(2,2,11,11);
insert into t1 values(3,3,3,4);
insert into t2 values(1,11,11);
insert into t2 values(1,11,11);
insert into t2 values(2,2,111);
insert into t2 values(2,2,111);
insert into t2 values(3,3,3);
insert into t2 values(3,3,3);
select * from t1 natural join t2;
select t1.c1,t1.c2,t1.c3 from t1,t2
where t1.c1 = t2.c1
and t1.c2 = t2.c2
and t1.c3 = t2.c3

using子句
select * from t1 join t2 using(c1);
select * from t1 join t2 using(c1,c2);
oracle语法
select t1.c1,t1.c2,t1.c3 from t1,t2 where t1.c1 = t2.c1
select t1.c1,t1.c2,t1.c3 from t1,t2 where t1.c1 = t2.c1 and t1.c2 = t2.c2;

SELECT employee_id, last_name,
location_id, department_id
FROM employees JOIN departments
USING (department_id) ;

using列出现在别的位置,不能用别名限定
SELECT l.city, d.department_name
FROM locations l JOIN departments d
USING (location_id)
WHERE d.location_id = 1400; (Not OK)

SELECT l.city, d.department_name
FROM locations l JOIN departments d
USING (location_id)
WHERE location_id = 1400; (OK)

on子句
SELECT e.employee_id, e.last_name, e.department_id,
d.department_id, d.location_id
FROM employees e JOIN departments d
ON (e.department_id = d.department_id);

SELECT e.employee_id, e.last_name, department_id, d.location_id
FROM employees e JOIN departments d
USING (department_id);

SELECT employee_id, city, department_name
FROM employees e
JOIN departments d
ON d.department_id = e.department_id
JOIN locations l
ON d.location_id = l.location_id;

oracle语法
SELECT employee_id, city, department_name
FROM employees e,departments d, locations l
WHERE d.department_id = e.department_id
AND d.location_id = l.location_id;

在join中应用额外条件
SELECT e.employee_id, e.last_name, e.department_id,
d.department_id, d.location_id
FROM employees e JOIN departments d
ON (e.department_id = d.department_id)
AND e.manager_id = 149 ;

SELECT e.employee_id, e.last_name, e.department_id,
d.department_id, d.location_id
FROM employees e JOIN departments d
ON (e.department_id = d.department_id)
WHERE e.manager_id = 149 ;

自连接:
SELECT worker.last_name emp, manager.last_name mgr
FROM employees worker JOIN employees manager
ON (worker.manager_id = manager.employee_id);

非等值连接
select ename, sal, grade
from emp join salgrade
on (sal between losal and hisal);

select ename, sal, grade
from emp,salgrade
where sal between losal and hisal;

外连接
create table e as select * from emp;
create table d as select * from dept;
select distinct deptno from e;
select deptno from d;
select ename, e.deptno,d.deptno from e join d on (e.deptno = d.deptno);
select ename, e.deptno,d.deptno from e right join d on (e.deptno = d.deptno);
select ename, e.deptno,d.deptno from e,d where e.deptno(+) = d.deptno;

insert into e values(8888,'ZhangHua','salesman',7698,'08-SEP-87',800,0, 50);
select ename, e.deptno,d.deptno from e left join d on (e.deptno = d.deptno);
select ename, e.deptno,d.deptno from e,d where e.deptno = d.deptno(+);

交叉连接(笛卡尔积)
SELECT ename,dname FROM emp cross join dept;
SELECT ename,dname FROM emp,dept;

Oracle SQL Lesson (6) - 使用Join进行联合查询的更多相关文章

  1. SQL Server中INNER JOIN与子查询IN的性能测试

    这个月碰到几个人问我关于"SQL SERVER中INNER JOIN 与 IN两种写法的性能孰优孰劣?"这个问题.其实这个概括起来就是SQL Server中INNER JOIN与子 ...

  2. Oracle SQL——inner jion;left join;right join的区别和使用场景

    背景 在一次面试的时候,面试官让我说一下这三者的使用场景和区别,当时瞬间懵逼,哈哈.回来赶快看一看,记下来. 详解 inner join 等值查询:返回两张表中,联结字段值相等的组合记录 举例:所有学 ...

  3. Oracle SQL Lesson (9) - 操作数据(增删改)

    使用INSERT语句INSERT INTO table [(column [, column...])]VALUES (value [, value...]); INSERT INTO departm ...

  4. Oracle SQL Lesson (2) - 限制和排序数据

    重建scott用户@?/rdbms/admin/utlsampl.sql@--执行?--$ORACLE_HOME 字符区分大小写:SELECT last_name, job_id, departmen ...

  5. Oracle SQL Lesson (1) - 使用SQL Select语句获取数据

    第一节课: 启动数据库并且使用特定用户连接:su - oracle; 启动sqlplus并且使用sys连接:conn / as sysdba; 启动数据库:startup; 解锁用户:alter us ...

  6. Oracle SQL Lesson (3) - 使用单行函数自定义输出

    大小写转换函数LOWER('SQL Course') = sql courseUPPER('SQL Course') = SQL COURSEINITCAP('SQL Course') = Sql C ...

  7. Oracle SQL Lesson (4) - 使用转换函数和条件表达式

    隐式转换select * from emp where empno='7788'字符(char,varchar2)转换为数字(number)或日期(date)数字或日期转换为字符 显式转换字符转换为数 ...

  8. Oracle SQL Lesson (11) - 创建其他数据库对象(试图/序列/索引/同义词)

    schema(模式)一个用户下一组对象的集合,一般与用户名一致. 视图 CREATE [OR REPLACE] [FORCE|NOFORCE] VIEW view [(alias[, alias].. ...

  9. Oracle SQL Lesson (5) - 使用组函数输出聚合数据

    组函数AVGCOUNTMAXMINSUMVARIANCE:方差STDDEV:标准差 SELECT AVG(salary), MAX(salary), MIN(salary), SUM(salary)F ...

随机推荐

  1. 联想A800新蜂ROM V1.1 基于官方4.0.4精简省电稳定

    ROM介绍 [出品]:新蜂工作室(基于官方) 1.源于官方:基于最稳定官方底包制作. 2.深度精简:自带APK数量从原厂包的131个降低到90个,精简31% 3.ROM包大小从原厂314MB精简到16 ...

  2. vs2008编译QT开源项目三国杀(五篇文章)

    请参看 http://tieba.baidu.com/f?kz=1508964881 按照上面的网址教程,下载三国杀源码,swig工具,并下载最新的QT4.8.2 for vs2008.我本机已经安装 ...

  3. 与众不同 windows phone (28) - Feature(特性)之手机方向, 本地化, 应用程序的试用体验, 系统主题资源, 本地数据的加密解密

    原文:与众不同 windows phone (28) - Feature(特性)之手机方向, 本地化, 应用程序的试用体验, 系统主题资源, 本地数据的加密解密 [索引页][源码下载] 与众不同 wi ...

  4. Oracle 验证IOT表数据存储在主键里

    iot表测试: 在create table语句后面使用organization index,就指定数据表创建结构是IOT.但是在不指定主键Primary Key的情况下,是不允许建表的. create ...

  5. C++ 多源码文件简单组织

    C++ 多源码文件简单组织 基本上和C的是一样的,只不过C++的方法要在类中声明.看一个简单实例.ainimal.h  类里面对外公开的信息. 点击(此处)折叠或打开 #ifndef _ANIMAL_ ...

  6. ANDROID L——Material Design综合应用(Demo)

    转载请注明本文出自大苞米的博客(http://blog.csdn.net/a396901990),谢谢支持! Material Design: Material Design是Google推出的一个全 ...

  7. ISO-8859-1乱码恢复

    为兼容较旧的jQuery插件,我把jQuery版本号从2.1.x降到了1.8.x,这比加入jquery-migration插件要来得干脆. 我没把这两个版本号的的区别一一记下来,而是直接改个版本号号. ...

  8. spring-framework-3.2.4.RELEASE 综合hibernate-release-4.3.5.Final一个错误Caused by: java.lang.NoClassDefFound

    LZ一体化的今天spring-framework-3.2.4.RELEASE 综合hibernate-release-4.3.5.Final一个错误Caused by: java.lang.NoCla ...

  9. UVALive 5790 Ball Stacking 解题报告

    比赛总结 题目 题意: 有n层堆成金字塔状的球,若你要选一个球,你必须把它上面那两个球取了,当然也可以一个不取.求选的球最大的权值和. 题解: 将这堆球转成举行,第一行是(0,0),第二个是(1,0) ...

  10. linux find命令强大之处

    find命令 find pathname -options [-print -exec -ok ...]   -print: find命令将匹配的文件输出到标准输出.   -exec: find命令对 ...