收集PL/SQL中的有用语句

数据库脚本导出：
1.首先导出:

exp user/pass@database file=d:/datadump.dmp full=y

2.按照如下方法导入就可以得到脚本:

imp user/pass@database file=d:/datadump.dmp full=y indexfile=d:/creatdatabase.txt

http://topic.csdn.net/t/20050119/17/3738712.html

[使用游标：]

1:最基本的游标
declare
wldm erp.itm_m.itm_wldm%type;
wlpm erp.itm_m.itm_wlpm%type;
cursor cur is
select itm_wldm,itm_wlpm from erp.itm_m where itm_wldm = '10001';
begin
open cur;
fetch cur into wldm,wlpm;
close cur;
dbms_output.put_line(wldm||wlpm);

end;

2: 加参数的游标
declare
wldm erp.itm_m.itm_wldm%type;
wlpm erp.itm_m.itm_wlpm%type;
cursor cur(v_wldm varchar2) is
select itm_wldm,itm_wlpm from erp.itm_m where itm_wldm = v_wldm;
begin
open cur('10001');
fetch cur into wldm,wlpm;
close cur;
dbms_output.put_line(wldm||wlpm);
end;

3:循环
set serveroutput on;
declare
wldm erp.itm_m.itm_wldm%type;
wlpm erp.itm_m.itm_wlpm%type;
cursor cur is
select itm_wldm,itm_wlpm from erp.itm_m ;
begin
/* 以下为 Loop ... End Loop循环 */
open cur;
loop
fetch cur into wldm,wlpm;
exit when cur%notfound or cur%notfound is null;
dbms_output.put_line(cur%rowcount ||' '||wldm||' '||wlpm);
end loop;
close cur;

/* 以下为while 循环*/
open cur;
fetch cur into wldm,wlpm;
while cur%found loop
dbms_output.put_line(cur%rowcount ||' '||wldm||' '||wlpm);
fetch cur into wldm,wlpm;
end loop;
close cur;
/* 以下为For 循环*/
for c_cur in cur loop
dbms_output.put_line(cur%rowcount ||' '||wldm||' '||wlpm);
end loop;
end;

4: 使用bulk collect
declare
type tp1 is table of erp.itm_m.itm_wlpm%type;
type tp2 is table of erp.itm_m.itm_wlgg%type;
v1 tp1;
v2 tp2;
cursor cur is
select itm_wlpm,itm_wlgg from erp.itm_m;
begin
open cur;
fetch cur bulk collect into v1,v2;
close cur;
for i in 1..v1.count loop
dbms_output.put_line(v1(i)||' ' ||v2(i));
end loop;
end;

5: for Update
set serveroutput on;
declare
wldm erp.itm_m.itm_wldm%type;
wlpm erp.itm_m.itm_wlpm%type;
cursor cur is
select itm_wldm,itm_wlpm from erp.itm_m for update ;
begin
for c_cur in cur loop
update erp.itm_m set itm_wlpm = itm_wlpm || '1'
where current of cur;
end loop;
end;

[if-else-endif]
set serveroutput on;
declare a int :=5;
v1 erp.itm_m%rowtype;
begin
select * into v1 from erp.itm_m where itm_wldm = '10001';
if a<3 then
dbms_output.put_line(v1.itm_wlpm);
elsif a<5 then -- 是elsif 不是 elseif
dbms_output.put_line(v1.itm_wlgg);
else
dbms_output.put_line(v1.itm_wldm);
end if;
end;

[loop]

declare i int:=0;
begin
loop
i :=i+1;
dbms_output.put_line(i);
if i>=3 then
exit;
end if;
end loop;

loop
i:=i-1;
dbms_output.put_line(i);
exit when i<=0;
end loop;

while i<=3 loop
i:=i+1;
dbms_output.put_line(i);
end loop;
dbms_output.put_line('i='||i);

for i in 1..3 loop
-- 此处不能赋值i:=i+1;
dbms_output.put_line(i);
end loop;
dbms_output.put_line('i='||i);

for i in reverse 1..3 loop
-- 此处不能赋值i:=i+1;
dbms_output.put_line(i);
end loop;
dbms_output.put_line('i='||i);
end;

[goto]
declare i int:=0;
begin
dbms_output.put_line(i);
loop
i:=i+1;
dbms_output.put_line(i);
exit when i>=5;
if i=3 then
goto xxx;
end if;
end loop;
return;
<<xxx>>
begin
dbms_output.put_line('end '||i);
end xxx;

dbms_output.put_line('end '||i);
end;

[exception]
-- Exception
declare x numeric:=10;y numeric:=0;z numeric;
begin
z:=x/y;
dbms_output.put_line(z);
exception
when others then
dbms_output.put_line('不能被0除');
end;

-- Raise 自定义Exception
declare my_exception exception;
x numeric:=10;y numeric:=20;z numeric;
begin
if x<y then
raise my_exception;
end if;
z:=x/y;
dbms_output.put_line(z);
exception
when my_exception then
dbms_output.put_line('被除数太小');
when zero_divide then
dbms_output.put_line('不能被0除');
end;

[top]
-- 我們想把最先進入公司的5個人找出來
SELECT * FROM emp WHERE ROWNUM <= 5 ORDER BY hiredate;
或
SELECT * FROM (SELECT * FROM emp ORDER BY hiredate)
WHERE ROWNUM <= 5;

-- 我們想把最先進入公司的6~10個人找出來!!!!!!!!!!!!!!
SELECT * FROM (SELECT * FROM emp ORDER BY hiredate)
WHERE ROWNUM <= 10
MINUS
SELECT * FROM (SELECT * FROM emp ORDER BY hiredate)
WHERE ROWNUM <= 5;

--测试：
create table test(depID varchar2(1),Name varchar2(10));
insert into test values('A', '一');
insert into test values('A' , '二');
insert into test values('A' , '三');
insert into test values('B' , '四');
insert into test values('B' , '五');
insert into test values('B' , '六');
insert into test values('C' , '七');
insert into test values('C' , '八');
insert into test values('C' , '九');
--语句：
select * from test a
where rowid in (select rowid from test where depid = a.depid and rownum<3);
/*结果
D NAME
- ----------
A 一
A 二
B 四
B 五
C 七
C 八

已选择6行。
*/

rownum是随着结果集生成的，一旦生成，就不会变化了；
同时,生成的结果是依次递加的，没有1就永远不会有2!
rownum 是在 查询集合产生的过程中产生的伪列，并且如果where条件中存在 rownum 条件的话，则:
1： 假如 判定条件是常量，则：
只能 rownum = 1, <= 大于1 的自然数， = 大于1 的数是没有结果的， 大于一个数也是没有结果的
即 当出现一个 rownum 不满足条件的时候则 查询结束

[transaction]

set serveroutput on;
declare n int;
begin
savepoint sp1;
update erp.inv_m set inv_kcsl = inv_kcsl+10;
n:=SQL%rowcount;
dbms_output.put_line(n);

savepoint sp2;
update erp.inv_m set inv_kcsl = inv_kcsl+10;
n:=SQL%rowcount;
dbms_output.put_line(n);

rollback to savepoint sp2;
end;

[trigger]
简单的：
create or replace trigger t_itm_m
after insert on erp.itm_m
for each row
begin
insert into erp.inv_m select :new.itm_wldm,100 from dual;
end;

create or replace trigger t_inv_m
before update on erp.inv_m
for each row
begin
dbms_output.put_line(:old.inv_wldm||' 更改前：':old.inv_kcsl||' 更改后:'||:new.inv_kcsl);
end;

系统触发器：
create table erp.log_table
(
log_user varchar2(30),
database_name varchar2(30),
event_name varchar2(20),
log_time date
);
1:登录
create or replace trigger user_logon
after logon on database
begin
insert into erp.log_table (log_user,database_name,event_name,log_time)
values(sys.login_user,sys.database_name,sys.sysevent,sysdate);
end;

2：退出登录
create or replace trigger user_logoff
before logoff on database
begin
insert into erp.log_table (log_user,database_name,event_name,log_time)
values(sys.login_user,sys.database_name,sys.sysevent,sysdate);
end;

3：启动数据库
create or replace trigger db_startup
after startup on database
begin
insert into erp.log_table (log_user,database_name,event_name,log_time)
values(sys.login_user,sys.database_name,sys.sysevent,sysdate);
end;

4:关闭数据库
create or replace trigger db_startup
before shutdown on database
begin
insert into erp.log_table (log_user,database_name,event_name,log_time)
values(sys.login_user,sys.database_name,sys.sysevent,sysdate);
end;

5: 记录创建表时的各类信息
create table erp.object_created
(
object_owner varchar2(30),
object_name varchar2(30),
object_type varchar2(20),
create_user varchar2(30),
create_time date
);

create or replace trigger t_create_object
after create on erp.schema
begin
insert into erp.object_created(
object_owner,object_name,object_type,create_user,create_time)
values(sys.dictionary_obj_owner,sys.dictionary_obj_name,sys.dictionary_obj_type,sys.login_user,sysdate);
end;

[function]
create or replace function f_getSum(wldm varchar2)
return numeric as
v_num numeric(10);
begin
select sum(inv_kcsl) into v_num
from erp.inv_m where inv_wldm like wldm || '%';
return v_num;
end;

--调用1：
set serveroutput on;
declare v_nm numeric(10);
begin
v_nm := f_getsum('101');
dbms_output.put_line(v_nm);
end;

--调用2：
select f_getSum('101') from dual;

[procedure]
create or replace procedure sp_inv_sl(v_sl in out numeric, v_flag in numeric :=0)
as
begin
if v_flag = -1 then
v_sl := -v_sl;
else
v_sl := v_sl;
end if;
update erp.inv_m set inv_kcsl = inv_kcsl + v_sl;
end;

--调用:
declare sl numeric(10) ;
begin
sl :=10;
sp_inv_sl(sl,-1);
end;

[package]

/*包头*/

create or replace package my_pack
as
function f_test(n integer) return integer;
end my_pack;

/*包主体*/
create or replace package body my_pack as

function f_test(n integer) return integer is
begin
return 1;
end f_test;

end my_pack;
/* 注意： 包头和包主体需分开编译*/

eg:
create or replace package my_pack as
type staff is table of varchar2(10);
procedure proc1(members in staff);
end my_pack;

create or replace package body my_pack as
procedure proc1(members in staff) is
begin
if members.count > 10 then
dbms_output.put_line('第一个为' || members(members.first));
else
dbms_output.put_line('最后一个为' || members(members.last));
end if;
end;
end my_pack;

declare
my_staff my_pack.staff;
begin
my_staff :=my_pack.staff('张三','李四','王五');
my_pack.proc1(my_staff);
end;

[嵌套表]

1:定义
create or replace type student as object
(
vid number(4),
vname varchar2(10),
vsex varchar2(2),
vaddress varchar2(40)
);

create type studentlist as table of student;

create table nest_table1
(
vid number(4),
vbj varchar2(14),
students studentlist
)
nested table students store as students_tab;

2: Insert
declare v_student studentlist :=studentlist(student(12,'张学友','男','深圳'));
begin
insert into nest_table1 values(1002,'歌星',v_student);
insert into nest_table1 values(1003,'球星',studentlist(student(13,'贝利','男','巴西')));
end;

3: Update
update nest_table1 set students = studentlist(student(12,'张学友','男','香港'))
where vid = 1002;

update the(select students from nest_table1 where vid = 1001)
set vaddress = '香港';

4: Select
select * from nest_table1;

select the(select students from nest_table1 where vid = 1001)
from dual;

[索引表]
1:基本索引表
set serveroutput on;
declare
type my_table is table of varchar(6) index by binary_integer;
v_mytable my_table;
begin
v_mytable(1) := 'a';
v_mytable(2) := 'b';
v_mytable(3) := 'c';
dbms_output.put_line(v_mytable(1)||v_mytable(2)||v_mytable(3));
end;

2：
declare
type my_table is table of erp.itm_m%rowtype index by binary_integer;
v_mytable my_table;
begin
select itm_wldm,itm_wlpm,itm_wlgg into v_mytable(1)
from erp.itm_m where itm_wldm = '10001';
dbms_output.put_line(v_mytable(1).itm_wldm ||v_mytable(1).itm_wlpm||v_mytable(1).itm_wlgg);
end;

3:
declare
type my_table is table of erp.itm_m%rowtype index by binary_integer;
v_mytable my_table;
begin
select itm_wldm,itm_wlpm,itm_wlgg into v_mytable(1)
from erp.itm_m where itm_wldm = '10001';
if v_mytable.exists(1) then
dbms_output.put_line(v_mytable(1).itm_wldm ||v_mytable(1).itm_wlpm||v_mytable(1).itm_wlgg);
else
dbms_output.put_line('不存在');
end if;
end;

4:
declare
type my_table is table of erp.itm_m%rowtype index by binary_integer;
v_mytable my_table;
begin
select itm_wldm,itm_wlpm,itm_wlgg into v_mytable(2)
from erp.itm_m where itm_wldm = '10001';
if v_mytable.exists(1) then
dbms_output.put_line(v_mytable(1).itm_wldm ||v_mytable(1).itm_wlpm||v_mytable(1).itm_wlgg);
else
dbms_output.put_line('不存在');
end if;

dbms_output.put_line(v_mytable(1).itm_wldm ||v_mytable(1).itm_wlpm||v_mytable(1).itm_wlgg);
exception
when no_data_found then
dbms_output.put_line('找不到');
end;

[同义词]

1:如下语句
select * from erp.tableName where rownum = 1;
因为表tableName是建在erp这个方案上的，每次都要写 erp.tableName才行，有没有什么设置可以用erp用户登录后就不用再写erp.tableName而直接写tableName

解决办法：
1：
建同义词：
CREATE PUBLIC SYNONYM tableName FOR PLAN_TABLE;
授权：
GRANT ALL ON tableName TO PUBLIC;

2:
用ERP用户，以NORMAL身份登录，而不是以SYSDBA身份登录。

同义词:
grant execute on hello_world to public;
create public synonym hello_world for erp.hello_world;

[动态SQL]

1:
set serveroutput on;
declare
v1 erp.itm_m.itm_wldm%type;
begin
execute immediate 'select itm_wldm from erp.itm_m where rownum =1'
into v1;
dbms_output.put_line(v1);
end;

2:
set serveroutput on;
declare
type t1 is table of erp.itm_m.itm_wldm%type;
v1 t1;
begin
execute immediate 'select itm_wldm from erp.itm_m where rownum <=3'
bulk collect into v1;
for i in v1.first .. v1.last loop
dbms_output.put_line(v1(i));
end loop;
end;

3:改进性能
create procedure test(par number) as
begin
execute immediate ''
end;

[行列转换]
http://community.csdn.net/Expert/topic/3222/3222974.xml?temp=.5841181

col1 col2
-----------------
0001 Tom
0001 Jack
0001 Mike
0002 Kate
0002 Rose
0002 Fene

如何用一条SQL语句得到如下结果：
col1 col2
-----------------
0001 Tom,Jack,Mike
0002 Kate,Rose,Fene

创建自定义函数：
create or replace function f_ename(jobno in varchar2)
return varchar2 is

str_return varchar2(200);
cursor c_ename(v_jobno varchar2) is select ename from emp where job=v_jobno;
begin
for str_temp in c_ename(jobno) loop
str_return:=str_return||str_temp.ename;
end loop;
return str_return;
end;
/

调用：
select job,f_ename(job) from (select distinct job from emp);

oracle 如何做行列动态的交叉表
http://community.csdn.net/Expert/topic/3093/3093861.xml?temp=.5882379
/*
Create table test (name varchar2(10),km varchar2(10),cj number)
go
insert into test values('张三','语文',80);
insert into test values('张三','数学',86);
insert into test values('张三','英语',75);
insert into test values('李四','语文',78);
insert into test values('李四','数学',85);
insert into test values('李四','英语',78);
select * from test;

select name,
sum(decode(km,'语文',cj,0)) as 语文,
sum(decode(km,'数学',cj,0)) as 数学,
sum(decode(km,'英语',cj,0)) as 英语
from test
group by name;
*/

CREATE OR REPLACE PACKAGE Pack_Test
AS
TYPE QUERY_CURSOR IS REF CURSOR;
PROCEDURE My_cur_out(
result out QUERY_CURSOR);
END Pack_Test;

CREATE OR REPLACE PACKAGE BODY Pack_Test
AS
PROCEDURE My_cur_out(
result out QUERY_CURSOR
)
AS
BEGIN

DECLARE
v_result varchar2(4000);
v_table varchar2(255):='TEST';--表名
v_col1 varchar2(255):='NAME'; --表的第一个列
v_col2 varchar2(255):='KM'; --表的第二个列
v_col3 varchar2(255):='CJ'; --表的第三个列
v_value varchar2(255);
v_file utl_file.file_type;
TYPE cur_type IS REF CURSOR;
cur_row cur_type;
BEGIN
v_result := 'SELECT '||v_col1;
OPEN cur_row FOR 'SELECT DISTINCT '||v_col2||' FROM '||v_table;
LOOP
FETCH cur_row INTO v_value;
EXIT WHEN cur_row%NOTFOUND;
v_result := v_result||',sum(decode('||v_col2||','''||v_value||''','||v_col3||','''')) as '||v_value;
END LOOP;
CLOSE cur_row;
v_result := v_result||' from '||v_table||' group by '||v_col1;

OPEN result FOR v_result;
END;

END;
END Pack_Test;

http://community.csdn.net/Expert/topic/3179/3179325.xml?temp=1.267642E-02
pl/sql怎么返回数据集?
CREATE OR REPLACE PACKAGE pkg_test
AS
TYPE myrctype IS REF CURSOR;

PROCEDURE get (p_id NUMBER, p_rc OUT myrctype);
END pkg_test;
/

CREATE OR REPLACE PACKAGE BODY pkg_test
AS
PROCEDURE get (p_id NUMBER, p_rc OUT myrctype)
IS
sqlstr VARCHAR2 (500);
BEGIN
IF p_id = 0 THEN
OPEN p_rc FOR
SELECT ID, NAME, sex, address, postcode, birthday
FROM student;
ELSE
sqlstr :=
'select id,name,sex,address,postcode,birthday
from student where id=:w_id';
OPEN p_rc FOR sqlstr USING p_id;
END IF;
END get;
END pkg_test;
/

[自增]
oracle中怎样将字段建成象SQL2000中的ID自动+1的字段
两种方法
方法一：
　　用触发器

建一个序列
create sequence a_seq increment by 1 start with 100;
建一个触发器, 自动+1
create or replace trigger your_seq_tri
before insert on your_table1 for each row
declare
next_id number;
begin
select your_seq.nextval into next_id from dual;
:new.id := next_id;
end;

方法二：
　　建一个序列
create sequence a_seq increment by 1 start with 100;
在语句中+1
　　insert into tbl(id,....)
values (a_seq.nextval,....)

[object]

create or replace type item as object
(
wldm varchar2(15), --明确的类型和长度，不能用%type
wlpm varchar2(20),
wlgg varchar2(40),
member function get_wldm return varchar2, -- 此处不能用 %type,不能指定varchar2的位数
member function get_pmgg return varchar2,
member procedure set_wldm(mwldm in varchar2) -- 同上 (in可以不需要)
) not final;

create or replace type body erp.item as
member function get_wldm return varchar2 is
begin
return wldm;
end;

member function get_pmgg return varchar2 is
begin
return wlpm || wlgg;
end;
member procedure set_wldm(mwldm varchar2) is
begin
wldm := mwldm;
end;

end;

成员函数，如果self没被声明，它的参数缺省为IN，然而在成员过程，如果SELF没被声明，它的参数模式缺省为IN OUT，不能指定SELF的参数模式为OUT.

ALTER TYPE ERP.ITEM ADD ATTRIBUTE(WLPM VARCHAR2(20));
ALTER TYPE ERP.ITEM ADD ATTRIBUTE(WLGG VARCHAR2(40));
ALTER TYPE ERP.ITEM DROP ATTRIBUTE WLPM;
ALTER TYPE ERP.ITEM DROP ATTRIBUTE WLGG;

ALTER TYPE ERP.ITEM ADD MEMBER FUNCTION get_pmgg return varchar2;

drop type body erp.item;
drop type erp.item;

调用示例：
declare itm erp.item := erp.item('1','a','b');
begin
dbms_output.put_line(itm.wlpm || ' ' || itm.get_pmgg);
end;

/*************************对象存入数据表字段***************************/
create table erp.test_obj
(
id integer,
itm erp.item
);
1:
insert into erp.test_obj values(1, erp.item('10001','歌星','刘德华') );
2:
declare itm erp.item := erp.item('10002','同事','刘文宏');
begin
insert into erp.test_obj values(2,itm);
insert into erp.test_obj values(3,erp.item('10003','同事','钟俊荣'));
end;
3:
update erp.test_obj D set D.itm.wlgg = '蔡然'
where id = 3;

declare v_itm erp.item := erp.item('10003','同事','蔡sir');
begin
update erp.test_obj d set d.itm = v_itm
where id = 3;
end;
/***********************对象表******************************/
create table erp.test_obj1 of erp.item;
insert into erp.test_obj1 values('10000','同事','刘文宏');
insert into erp.test_obj1 select * from erp.itm_m;

############################复杂查询语句的使用#####################################
1.查询语句的使用
使用 select语句和子查询(subquery)可以从一个或多个表,视图,实体试图中返回数据.

1.1相关子查询
可以将子查询(as subquery)或in或exists当成where的一个条件的一部分,这样的查询称为子查询
.where中可以包含一个select语句的子查询
.where中可以包含in,exists语句
.最多可以嵌套16层
.层次过多会影响性能
[例]简单子查询实例
查询是否有的专家既以研究所的名义来申请基金项目,又以大学系为单位申请项目
(按规定只能以一个单位来申请)
SQL> create table univ_subject
2 (
3 name varchar2(12) not null,
4 per_id number not null,
5 dept_name varchar2(20)
6 );
SQL> insert into univ_subject values('gaoqianjing',1001,'信息工程系');
SQL> insert into univ_subject values('wangbing',1002,'物理系');
SQL> insert into univ_subject values('liming',1003,'化学系');
===============
SQL> create table colle_subject
2 (
3 colle_name varchar2(20),
4 per_id number
5 );
SQL> insert into colle_subject values('电子研究所',1001);
SQL> insert into colle_subject values('物理研究所',1005);
================
SQL> select name,per_id,dept_name from univ_subject where per_id in
2 (select per_id from colle_subject);

NAME PER_ID DEPT_NAME
------------ --------- --------------------
gaoqianjing 1001 信息工程系

1.2外连接
[例]外连接实例
招生中所有学生的信息放在students表中,而部分有特长的学生在另一个表中stuent_skill中同样有该学生
的信息。现在要全部列出所有学生,如果某个学生在表student_skill中就有其特长信息,并显示特长信息,如果
某个学生没有特长就显示特长问空.
SQL> create table students
2 (
3 st_id varchar2(20),
4 name varchar2(10),
5 age number(2),
6 tol_score number(3)
7 ) ;
SQL> insert into students values('973231','wangbindu',22,501);
SQL> insert into students values('973232','zhuzhijing',21,538);
SQL> insert into students values('973233','gaojing',21,576);
===================

SQL> create table student_skill
2 (
3 st_id varchar2(20),
4 skill varchar2(20)
5 );
SQL> insert into student_skill values('973231','篮球');
SQL> insert into student_skill(st_id) values('973232');
SQL> insert into student_skill values('973233','足球');
===================

SQL> select a.* , b.skill from students a,student_skill b where a.st_id=b.st_id(+)
order by a.st_id;

ST_ID NAME AGE TOL_SCORE SKILL
-------------------- ---------- --------- --------- ------------------ --
973231 wangbindu 22 501 篮球
973232 zhuzhijing 21 538
973233 gaojing 21 576 足球

1.3自我连接
自我连接是在同一个表或视图内进行条件连接.
[例]自我连接实例
查询每个雇员的名字和该雇员的经理的名字:
SQL> select e1.ename||' work for '||e2.ename "Employees and their Managers"
2 from scott.emp e1,scott.emp e2 where e1.mgr=e2.empno;

Employees and their Managers
-------------------------------------------------
SMITH work for FORD
ALLEN work for BLAKE
WARD work for BLAKE
JONES work for KING
MARTIN work for BLAKE
BLAKE work for KING
CLARK work for KING
SCOTT work for JONES
TURNER work for BLAKE
ADAMS work for SCOTT
JAMES work for BLAKE
FORD work for JONES
MILLER work for CLARK

1.4UNION , INTERSECT及 MINUS
UNION: 可以将两个以上的表的相类似的查询结果放在一起 (union all则表示返回所有的行)
具体语法:
select ...
union[all]
select...
==========

INTERSECT: 返回两个表中相同的信息
具体语法:
select ...
intersect
select...
==========

MINUS : 返回一个表中出现的信息
具体语法:
select ...
minus
select...
[例1]UNION操作实例
SQL> select st_id from students
2 union
3 select st_id from student_skill;

ST_ID
--------------------
973231
973232
973233

[例2]INTERSECT操作实例
列出有特长的学生的学号
SQL> select st_id from students
2 intersect
3 select st_id from student_skill;
ST_ID
--------------------
973231
973233

[例3]MINUS操作实例
列出没有特长学生的学号
select st_id from students
minus
select st_id from student_skill;
ST_ID
--------------------
973232

2.创建复杂的视图
许多应用系统有统计等功能,建议最好把这些复杂语句写成视图.下面是几个常用的视图.
2.1分组视图
[例1]简单的分组视图
SQL> create or replace view dept_tot as
2 select a.dname dept,sum(b.sal) total_sal from scott.dept a,scott.emp b
3 where a.deptno=b.deptno group by a.dname;

查看已建立。
SQL> select * from dept_tot;

DEPT TOTAL_SAL
-------------- ---------
ACCOUNTING 8750
RESEARCH 10875
SALES 9400

[例2]带复杂函数视图
SQL> create or replace view itemtot as
2 select persion,sum(amount) itemtot from ledger
3 where actiondate between
4 to_date('01-MAR-1901','dd-mon-yyyy') and
5 to_date('31-MAR-1901','dd-mon-yyyy')
6 and action in('bought','raid') group by persion;

2.2合计视图
[例]合计函数视图实例
SQL> create or replace view emp_no1 as
2 select deptno,sum(sal) 工资和,sum(comm) 总和
3 from scott.emp group by deptno;
SQL> select * from emp_no1;
DEPTNO 工资和 总和
--------- --------- ---------
10 8750
20 10875
30 9400 2200

2.3组合视图
[例]带组合函数的视图
SQL> create or replace view byitem as
2 select l.persion persion.item, amount, 100*amount/item bypersion,100*amount/total bytotal
3 from ledgent l,itemtotal i,total where l.persion=i.persion where l.persion=i.persion
4 and actiondate between
5 to_date('01-MAR-1901','dd-mon-yyyy') and
6 to_date('31-MAR-1901','dd-mon-yyyy')
7 and action in('bought','raid') ;

3.家族树
语法:
select column from table_name start with column=value
connect by prior 父主键=子主键

3.1排除单一性和分枝
以ORACLE中的EMP表为例
[例]从顶到底列出各雇员的信息
SQL> select lpad(' ',4*(level-1))||ename name,empno,mgr from emp start with mgr is null
2 connect by prior empno=mgr;

NAME EMPNO MGR
--------- --------- ---------
KING 7839
JONES 7566 7839
SCOTT 7788 7566
ADAMS 7876 7788

3.2遍历至根
[例1]现在要从某个雇员开始向他的上级列出该雇员的层次结构
SQL> col ename for a30;
SQL> select lpad(' ',4*(level-1))||ename ename,mgr,empno from scott.emp
2 start with mgr=7788 connect by prior mgr=empno;
ENAME MGR EMPNO
------------------------------ --------- ---------
ADAMS 7788 7876
SCOTT 7566 7788
JONES 7839 7566
KING 7839

[例2]列出所有雇员的层次结构
SQL> select lpad(' ',4*(level-1))||ename ename,empno,mgr from scott.emp
2 start with mgr is not null
3 connect by empno=prior mgr;

ENAME EMPNO MGR
------------------------------ --------- ---------
SMITH 7369 7902
FORD 7902 7566
JONES 7566 7839
KING 7839
ALLEN 7499 7698
BLAKE 7698 7839
KING 7839
WARD 7521 7698
BLAKE 7698 7839
KING 7839
JONES 7566 7839
KING 7839
MARTIN 7654 7698
BLAKE 7698 7839
KING 7839
BLAKE 7698 7839
KING 7839
CLARK 7782 7839
KING 7839
SCOTT 7788 7566
JONES 7566 7839

==================================================

[增加顺序号]

情况:
有店铺A,B,C,记录N条,增加一个顺序号列(seq),让他们象下面的形式排列:

storecode seq name amt
A 1 a1 1
A 2 a2 1
A 3 a3 1
B 1 b1 1
B 2 b2 1
B 3 b3 1
C 1 c1 1
C 2 c2 1

CREATE OR REPLACE PACKAGE repPack115 as
type resultset is ref cursor;
procedure rep115(v_storecode varchar2,v_qsrq varchar2,v_zzrq varchar2,v_sortby varchar2,v_seq varchar2,ret_cursor out resultset);

end repPack115;
/
CREATE OR REPLACE package body repPack115
as
/*
name:rep115 descirp:it can query the best sales product info between two period seperate by the store
params:
v_storecode :selected stores,let it null it want to select all stores
v_qsrq :the first date
v_zzrq :the last date
v_sortby :which coloumn you want to sort by
v_seq :asc or desc can selected

ver:1.0 author:simon

*/
procedure rep115(v_storecode varchar2,v_qsrq varchar2,v_zzrq varchar2,v_sortby varchar2,v_seq varchar2,ret_cursor out resultset)
is
tabl number;
sqlstr varchar2(4000);
begin
select count(*) into tabl from all_tables a where a.table_name='REP115_SALES';

if tabl>0 then
sqlstr := 'TRUNCATE TABLE ST1CNA.REP115_SALES';
execute immediate sqlstr;
sqlstr := 'INSERT INTO ST1CNA.REP115_SALES select rownum as qid,xf_storecode,itemno,chsdescription,engdescription,retailprice,saleqty,saleamount from (select c.xf_storecode,a.xf_plu as itemno,max(a.xf_desci) as chsdescription,max(a.xf_longdesc) as engdescription,max(b.xf_seluprice) as retailprice,sum(c.xf_qtysold) as saleqty,sum(xf_amtsold) as saleamount from xf_itemmas a,xf_priceh b,xf_vipitemdm c where a.xf_style=b.xf_style and a.xf_plu=c.xf_plu and c.xf_txdate<=to_date('''||v_zzrq||''',''yyyy-mm-dd'') and c.xf_txdate>=to_date('''||v_qsrq||''',''yyyy-mm-dd'') group by c.xf_storecode,a.xf_plu order by xf_storecode,'||v_sortby||' '||v_seq||') a ';
execute immediate sqlstr;
else
sqlstr := 'create global temporary table ST1CNA.REP115_SALES on commit preserve rows as select rownum as qid,xf_storecode,itemno,chsdescription,engdescription,retailprice,saleqty,saleamount from (select c.xf_storecode,a.xf_plu as itemno,max(a.xf_desci) as chsdescription,max(a.xf_longdesc) as engdescription,max(b.xf_seluprice) as retailprice,sum(c.xf_qtysold) as saleqty,sum(xf_amtsold) as saleamount from xf_itemmas a,xf_priceh b,xf_vipitemdm c where a.xf_style=b.xf_style and a.xf_plu=c.xf_plu and c.xf_txdate<=to_date('''||v_zzrq||''',''yyyy-mm-dd'') and c.xf_txdate>=to_date('''||v_qsrq||''',''yyyy-mm-dd'') group by c.xf_storecode,a.xf_plu order by xf_storecode,'||v_sortby||' '||v_seq||') a ';
execute immediate sqlstr;

end if;

if v_storecode is null then
sqlstr := 'select * from (select case when (select count(*) from ST1CNA.REP115_SALES a where a.xf_storecode=ST1CNA.REP115_SALES.xf_storecode and a.qid<=ST1CNA.REP115_SALES.qid)<=30 then (select count(*) from ST1CNA.REP115_SALES a where a.xf_storecode=ST1CNA.REP115_SALES.xf_storecode and a.qid<=ST1CNA.REP115_SALES.qid) else 0 end qqid,xf_storecode,itemno,chsdescription,engdescription,retailprice,saleqty,saleamount from ST1CNA.REP115_SALES) b where qqid<>0';
else
sqlstr := 'select * from (select case when (select count(*) from ST1CNA.REP115_SALES a where a.xf_storecode=ST1CNA.REP115_SALES.xf_storecode and a.qid<=ST1CNA.REP115_SALES.qid)<=30 then (select count(*) from ST1CNA.REP115_SALES a where a.xf_storecode=ST1CNA.REP115_SALES.xf_storecode and a.qid<=ST1CNA.REP115_SALES.qid) else 0 end qqid,xf_storecode,itemno,chsdescription,engdescription,retailprice,saleqty,saleamount from ST1CNA.REP115_SALES) b where qqid<>0 and xf_storecode in '||v_storecode;

end if;

open ret_cursor for sqlstr;

end rep115;

end repPack115;
/