SELECT * FROM STUDENT CROSS JOIN TEACHER;--交叉连接
SELECT * FROM STUDENT S INNER JOIN TEACHER T ON S.TEACHER_ID=T.ID;--内连接
SELECT * FROM STUDENT S LEFT OUTER JOIN TEACHER T ON S.TEACHER_ID=T.ID;--左外连接
SELECT * FROM STUDENT S RIGHT OUTER JOIN TEACHER T ON S.TEACHER_ID=T.ID;--右外连接
SELECT * FROM STUDENT S FULL OUTER JOIN TEACHER T ON S.TEACHER_ID=T.ID;--全外连接

--视图
CREATE VIEW tea_stu_view ASSELECT s.id,s.name,t.tea_name FROM STUDENT S INNER JOIN TEACHER T ON S.TEACHER_ID=T.ID;
--视图调用
SELECT * FROM tea_stu_view;

--存储过程
CREATE OR REPLACE FUNCTION this_is_function(table_name text,column_name text) RETURNS INTEGER AS $maxId$declaremysql text;myID integer;beginmysql:='select max('|| quote_ident(column_name) || ')from '|| quote_ident(table_name);execute mysql into myID;if myID is null or myID=0 then return 1;else return myID+1;end if;end;
$maxId$ language plpgsql;
--执行存储过程
select this_is_function('teacher','id')；

--触发器调用函数
CREATE OR REPLACE FUNCTION trigger_fun() RETURNS TRIGGER as $trigger_fun$declaremyID integer;mysql text;beginmysql:='select max(id)+1 from teacher ';execute mysql into myID;if tg_op='INSERT' thenINSERT INTO public.teacher(id,tea_name) values (myID,'红老师');end if;return null;end;
$trigger_fun$ language plpgsql;
--创建触发器
CREATE TRIGGER trigger_fun AFTER INSERT ON student for each row execute procedure trigger_fun();
--触发器触动方式
insert into public.student(id,name,sex,teacher_id) values (6,'小三','男','3');

--创建序列
create sequence test_seq increment by 1 minvalue 1 no maxvalue start with 1;
select nextval('test_seq'); --序列调用--建索引
CREATE INDEX student_index  ON student(teacher_id);