马士兵oracle视频教程笔记
第一課：客戶端
1. Sql Plus(客戶端），命令行直接輸入：sqlplus，然后按提示輸入用戶名，密碼。
2. 從開(kāi)始程序運(yùn)行:sqlplus，是圖形版的sqlplus.
3. http://localhost:5560/isqlplus
第二課：更改用戶
1. sqlplus sys/bjsxt as sysdba
2. alter user scott account unlock;(解鎖)
第三課：table structure
1. 描述某一張表：desc 表名:desc emp 、desc dept 、desc salgrade
2. select * from 表名
第四課：select 語(yǔ)句：
1.計(jì)算數(shù)據(jù)可以用空表：比如：.select 2*3 from dual
2.select ename,sal*12 annual_sal from emp;與select ename,sal*12 "annual sal" from emp;區(qū)別，別名不要用"_"連接起來(lái)，同時(shí)加了雙引號(hào)可以保持住原來(lái)的格式。
3. select ename || ‘a(chǎn)bcd’。如果連接字符串中含有單引號(hào)，用兩個(gè)單引號(hào)代替一個(gè)單引號(hào)；“||”相當(dāng)于java中的“+”
4.select sysdate from dual;顯示當(dāng)前時(shí)間
第五課：distinct
select deptno from emp;
select distinct deptno from emp;
select distinct deptno from emp;
select distinct deptno ,job from emp
去掉deptno,job兩者組合的重復(fù)。更多的項(xiàng)，就是這么多項(xiàng)的組合的不重復(fù)組合。
第六課：Where
select * from emp where deptno =10;
select * from emp where deptno <> 10;不等于10
select * from emp where ename ='bike';
select ename,sal from emp where sal between 800 and 1500 (>=800 and <=1500)
空值處理:
select ename,sal,comm from emp where comm is (not) null;
select ename,sal,comm from emp where ename ( not)in ('smith','king','abc');
select ename from emp where ename like '_A%';_代表一個(gè)字母,%代表0個(gè)或多個(gè)字母. 如果查詢%
可用轉(zhuǎn)義字符.\%. 還可以用escape '$'比如:select ename from emp where ename like '%$a%' escape '$';
第七課: order by
select * from dept;
select * from dept order by dept desc;(默認(rèn):asc)
select ename,sal,deptno from emp order by deptno asc,ename desc;先按照deptno升序，如果數(shù)據(jù)相同則按照ename降序
第八課: sql function1:
select ename,sal*12 annual_sal from emp
where ename not like '_A%' and sal>800
order by sal desc;
select lower(ename) from emp;
select ename from emp
where lower(ename) like '_a%';等同于
select ename from emp where ename like '_a%' or ename like '_A%';
select substr(ename,2,3) from emp;從第二字符截,一共截三個(gè)字符.
select chr(65) from dual 結(jié)果為:A
select ascii('A') from dual 結(jié)果為:65
select round(23.652,1) from dual; 結(jié)果為: 23.7
select round(23.652,-1) from dual;20 四舍五入到十位數(shù)
select to_char(sal,'$99_999_999') from emp;//'$99_999_999'是指定的格式，9代表一位數(shù)字
select to_char(sal,'L99_999_999') from emp;人民幣符號(hào),L:代表本地符號(hào)
這個(gè)需要掌握牢:
select birthdate from emp;
顯示為:
BIRTHDATE
----------------
17-12月-80
----------------
改為:
select to_char(birthdate,'YYYY-MM-DD HH:MI:SS') from emp;
顯示:
BIRTHDATE
-------------------
1980-12-17 12:00:00
-------------------
select to_char(sysdate,'YYYY-MM-DD HH24:MI:SS') from dual; //也可以改為:HH12
TO_CHAR(SYSDATE,'YY
-------------------
2007-02-25 14:46:14
to_date函數(shù):
select ename,birthdate from emp where birthdate > to_date('1981-2-20 12:34:56','YYYY-MM-DD HH24:MI:SS');
如果直接寫 birthdate>'1981-2-20 12:34:56'會(huì)出現(xiàn)格式不匹配,因?yàn)楸碇械母袷綖? DD-MM月-YY.
select sal from emp where sal>888.88 無(wú)錯(cuò).但
select sal from emp where sal>$1,250,00;
會(huì)出現(xiàn)無(wú)效字符錯(cuò)誤.
改為:
select sal from emp where sal>to_number('$1.250.00','$9,999,99');
把空值改為0
select ename,sal*12+nvl(comm,0) from emp;
這樣可以防止comm為空時(shí),sal*12相加也為空的情況.
第九課: Group function 組函數(shù)
max,min,avg ,count,sum函數(shù)
select to_char(avg(sal),'99999999,99') from emp;
select round(avg(sal),2) from emp;
結(jié)果:2073.21
select count(*) from emp where deptno=10;
select count(ename) from emp where deptno=10; count某個(gè)字段,如果這個(gè)字段不為空就算一個(gè).
select count(distinct deptno) from emp;
select sum(sal) from emp;
第十課: Group by語(yǔ)句
需求:現(xiàn)在想求,求每個(gè)部門的平均薪水.
select avg(sal) from emp group by deptno;
select deptno,avg(sal) from emp group by deptno;
select deptno,job,max(sal) from emp group by deptno,job;
求薪水值最高的人的名字.
select ename,max(sal) from emp;出錯(cuò),因?yàn)閙ax只有一個(gè)值,但等于max值的人可能好幾個(gè),不能匹配.
應(yīng)如下求:
select ename from emp where sal=(select max(sal) from emp);
Group by語(yǔ)句應(yīng)注意,
出現(xiàn)在select中的字段,如果沒(méi)出現(xiàn)在組函數(shù)中,必須出現(xiàn)在Group by語(yǔ)句中.
第十一課: Having 對(duì)分組結(jié)果篩選
Where是對(duì)單條紀(jì)錄進(jìn)行篩選,Having是對(duì)分組結(jié)果進(jìn)行篩選.
select avg(sal),deptno from emp
group by deptno
having avg(sal)>2000;
查詢工資大于1200雇員,按部門編號(hào)進(jìn)行分組,分組后平均薪水大于1500,按工薪倒充排列.
select * from emp
where sal>1200
group by deptno
having avg(sal)>1500
order by avg(sal) desc;
第十二課:子查詢
誰(shuí)掙的錢最多(誰(shuí):這個(gè)人的名字, 錢最多)
select 語(yǔ)句中嵌套select 語(yǔ)句,可以在where,from后.
問(wèn)那些人工資,在平均工資之上.
select ename,sal from emp where sal>(select avg(sal) from emp);
查找每個(gè)部門掙錢最多的那個(gè)人的名字.
select ename ,deptno from emp where sal in(select max(sal) from ename group by deptno) 查詢會(huì)多值.
應(yīng)該如下:
select max(sal),deptno from emp group by deptno;當(dāng)成一個(gè)表.語(yǔ)句如下:
select ename, sal from emp join(select max(sal) max_sal,deptno from emp group
by deptno) t on(emp.sal=t.max_sal and emp.deptno=t.deptno);
每個(gè)部門的平均薪水的等級(jí).
分析:首先求平均薪水(當(dāng)成表),把平均薪水和另外一張表連接.
第十四課:self_table_connection(自連接)：給同一個(gè)表取相同的別名
把某個(gè)人的名字以及他的經(jīng)理人的名字求出來(lái)(經(jīng)理人及這個(gè)人在表中同處一行)
分析:首先求出這個(gè)人的名字,取他的編號(hào),然后從另一張表與其相對(duì)應(yīng)編號(hào),然后找到經(jīng)理的名字.
select e1.ename ,e2.ename from emp e1,emp e2 where e1.mgr= e2.empno.
empno編號(hào)和MGR都是編號(hào).
第十15課: SQL1999_table_connections
select ename,dname,grade from emp e,dept d, sqlgrade s
where e.deptno = d.deptno and e.sql between s.losal and s.hisal and
job<>'CLERK';
有沒(méi)有辦法把過(guò)濾條件和連接條件分開(kāi)來(lái)? 出于這樣考慮,Sql1999標(biāo)準(zhǔn)推出來(lái)了.有許多人用的還是
舊的語(yǔ)法,所以得看懂這種語(yǔ)句.
select ename,dname from emp,dept;(舊標(biāo)準(zhǔn)).
select ename,dname from emp cross join dept;(1999標(biāo)準(zhǔn))
select ename,dname from emp,dept where emp.deptno=dept.deptno (舊)
select ename,dname from emp join dept on(emp.deptno = dept.deptno); 1999標(biāo)準(zhǔn).沒(méi)有Where語(yǔ)句.
select ename,dname from emp join dept using(deptno);等同上句,但不推薦使用.
select ename,grade from emp e join salgrade s on(e.sal between s.losal and s.hisal);
join 連接語(yǔ)句, on過(guò)濾條件。連接，條件一眼分開(kāi)。如果用Where語(yǔ)句較長(zhǎng)時(shí)，連接語(yǔ)句和過(guò)濾語(yǔ)句混在一起。
三張表連接：
slect ename,dname, grade from
emp e join dept d on(e.deptno=d.deptno)
join salgrade s on(e.sal between s.losal and s.hisal)
where ename not like '_A%';
把每張表連接 條件不混在一起，然后數(shù)據(jù)過(guò)濾條件全部區(qū)分開(kāi)來(lái)。讀起來(lái)更清晰，更容易懂一點(diǎn)。
select e1.ename,e2.ename from emp e1 join emp e2 on(e1.mgr = e2.emptno);
左外連接：會(huì)把左邊這張表多余數(shù)據(jù)顯示出來(lái)。
select e1.ename,e2,ename from emp e1 left join emp e2 on(e1.mgr =e2.empno);left 后可加outer
右外連接：
select ename,dname from emp e right outer join dept d on(e.deptno =d.deptno); outer可以取掉。
即把左邊多余數(shù)據(jù)，也把右邊多余數(shù)據(jù)拿出來(lái)，全外連接。
select ename,dname from emp e full join dept d on(e.deptno =d.deptno);
16-23 課：求部門平均薪水的等級(jí)
A.求部門平均薪水的等級(jí)。
select deptno,avg_sal,grade from
(select deptno,avg(sal) avg_sal from emp group by deptno)t
join salgrade s on(t.avg_sal between s.losal and s.hisal)
B.求部門平均的薪水等級(jí)
select deptno,avg(grade) from
(select deptno,ename, grade from emp join salgrade s on(emp.sal between s.losal and
s.hisal)) t
group by deptno
C.哪些人是經(jīng)理
select ename from emp where empno in(select mgr from emp);
select ename from emp where empno in(select distinct mgr from emp);
D.不準(zhǔn)用組函數(shù)，求薪水的最高值（面試題）
select distinct sal from emp where sal not in(
select distinct e1.sal from emp e1 join emp e2 on (e1.sal<e2.sal));
E.平均薪水最高的部門編號(hào)
select deptno,avg_sal from
(select avg(sal)avg_sal,deptno from emp group by deptno)
where avg_sal=
(select max(avg_sal)from
(select avg(sal) avg_sal,deptno from emp group by deptno)
)
F.平均薪水最高的部門名稱
select dname from dept where deptno=
(
select deptno from
(select avg(sal)avg_sal,deptno from emp group by deptno)
where avg_sal=
(select max(avg_sal)from
(select avg(sal) avg_sal,deptno from emp group by deptno)
)
)
G.求平均薪水的等級(jí)最低的部門的部門名稱
組函數(shù)嵌套
如：平均薪水最高的部門編號(hào)，可以E.更簡(jiǎn)單的方法如下：
select deptno,avg_sal from
(select avg(sal) avg_sal,deptno from emp group by deptno)
where avg_sal =
(select max(avg(sal)) from emp group by deptno)
組函數(shù)最多嵌套兩層
分析：
首先求
1.平均薪水： select avg(sal) from group by deptno;
2.平均薪水等級(jí)： 把平均薪水當(dāng)做一張表，需要和另外一張表連接salgrade
select deptno,grade avg_sal from
( select deptno,avg(sal) avg_sal from emp group by deptno) t
join salgrade s on(t.avg_sal between s.losal and s.hisal)
上面結(jié)果又可當(dāng)成一張表。
DEPTNO GRADE AVG_SAL
-------- ------- ----------
30 3 1566.66667
20 4 2175
10 4 2916.66667
3.求上表平均等級(jí)最低值
select min(grade) from
(
select deptno,grade,avg_sal from
(select deptno,avg(sal) avg_sal from emp group by deptno)t
join salgrade s on(t.avg_sal between s.losal and s.hisa)
)
4.把最低值對(duì)應(yīng)的2結(jié)果的那張表的對(duì)應(yīng)那張表的deptno, 然后把2對(duì)應(yīng)的表和另外一張表做連接。
select dname ,deptno,grade,avg_sal from
(
? select deptno,grade,avg_sal from
(select deptno,avg(sal) avg_sal from emp group by deptno)t
join salgrade s on(t.avg_sal between s.losal and s.hisal)
) t1
join dept on (t1.deptno = dept.deptno)
where t1.grade =
(
select deptno,grade,avg_sal from
(select deptno,avg(sal) avg_sal from emp group by deptno) t
join salgrade s on(t.avg_sal between s.losal and s.hisal)
)
)
結(jié)果如下：
DNAME DEPTNO GRADE AVG_SAL
-------- ------- -------- --------
SALES 30 3 1566.6667
H: 視圖（視圖就是一張表，一個(gè)字查詢）
G中語(yǔ)句有重復(fù)，可以用視圖來(lái)簡(jiǎn)化。
conn sys/bjsxt as sysdba;
grant create table,create view to scott;
conn scott/tiger
創(chuàng)建視圖：
create view v$_dept_avg-sal_info as
select deptno,grade,avg_sal from
( select deptno,avg(sal) avg_sal from emp group by deptno)t
join salgrade s on 9t.avg_sal between s.losal and s.hisal)
然后
select * from v$_dept_avg-sal_info
結(jié)果如下：
DEPTNO GRADE AVG_SAL
-------- ------- ----------
30 3 1566.66667
20 4 2175
10 4 2916.66667
然后G中查詢可以簡(jiǎn)化成：
select dname,t1.deptno,grade,avg_sal from
v$_dept_avg-sal_info t1
join dept on9t1.deptno =dept.deptno)
where t1.grade=
(
select min(grade) from v$_dept_avg-sal_info t1
)
創(chuàng)建新用戶：
1.backup scott
exp
2.create user
1)Create user fanjiabin identified by fanjiabin default tablespace users quota 10M on users
2)grant create session,cteate table,cteate view to fanjiabin
3.import the data
imp
--變量聲明，使用%type屬性
declare
v_empno number(4);
v_empno2 emp.empno%type;
v_empno3 v_empno2%type;
begin
dbms_output.put_line('test');
end;
--table變量類型(數(shù)組)
declare
type type_table_emp_empno is table of emp.empno%type index by binary_integer;
v_empnos type_table_emp_empno;
begin
v_empnos(0) := 7369;
v_empnos(2) := 7839;
v_empnos(-1) := 9999;
dbms_output.put_line(v_empnos(-1));
end;
--record變量類型（近似java中的類）
declare
type type_record_dept is record
(
deptno dept.deptno%type,
dname dept.dname%type,
loc dept.loc%type
);
v_temp type_record_dept;
begin
v_temp.deptno := 50;
v_temp.dname := 'aaa';
v_temp.loc := 'bj';
dbms_output.put_line(v_temp.deptno || ' ' || v_temp.dname);
end;
--使用%rowtype聲明record變量
declare
v_temp dept%rowtype;
begin
v_temp.deptno := 50;
v_temp.dname := 'aaa';
v_temp.loc := 'bj';
dbms_output.put_line(v_temp.deptno || ' ' || v_temp.dname);
end;
--SQL語(yǔ)句的運(yùn)用
--select語(yǔ)句
declare
v_name emp.ename%type;
v_sal emp.sal%type;
begin
select ename, sal into v_name, v_sal from emp where empno = 7369;
dbms_output.put_line(v_name || ' ' || v_sal);
end;
declare
v_emp emp%rowtype;
begin
select * into v_emp from emp where empno = 7369;
dbms_output.put_line(v_emp.ename);
end;
--insert語(yǔ)句
declare
v_deptno dept.deptno%type := 50;
v_dname dept.dname%type := 'aaa';
v_loc dept.loc%type := 'bj';
begin
insert into dept2 values(v_deptno, v_dname, v_loc);
commit;
end;
declare
v_deptno emp2.deptno%type := 10;
v_count number;
begin
--update emp2 set sal = sal/2 where deptno = v_deptno;
--select deptno into v_deptno from emp2 where empno = 7369;
select count(*) into v_count from emp2;
dbms_output.put_line(sql%rowcount || '條記錄被影響');
commit;
end;
DDL語(yǔ)句
begin
execute immediate 'create table t (nnn varchar2(20) default ''aaa'')';
end;
--if語(yǔ)句
取出7369的薪水，如果<1200，輸出'low'，如果<2000輸出'middle'，否則'high'
declare
v_sal emp.sal%type;
begin
select sal into v_sal from emp
where empno = 7369;
if (v_sal < 1200) then
dbms_output.put_line('low');
elsif (v_sal < 2000) then
dbms_output.put_line('middle');
else
dbms_output.put_line('high');
end if;
end;
--練習(xí)
--循環(huán)
declare
i binary_integer := 1;
begin
loop
dbms_output.put_line(i);
i := i + 1;
exit when (i >= 11);
end loop;
end;
---------
declare
j binary_integer := 1;
begin
while j < 11 loop
dbms_output.put_line(j);
j := j + 1;
end loop;
end;
-----------
begin
for k in 1..10 loop
dbms_output.put_line(k);
end loop;
for k in reverse 1..10 loop
dbms_output.put_line(k);
end loop;
end;
--錯(cuò)誤處理
declare
v_temp number(4);
begin
select empno into v_temp from emp where empno = 10;
exception
when too_many_rows then
dbms_output.put_line('太多紀(jì)錄了');
when others then
dbms_output.put_line('error');
end;
----------
declare
v_temp number(4);
begin
select empno into v_temp from emp where empno = 2222;
exception
when no_data_found then
dbms_output.put_line('沒(méi)有數(shù)據(jù)');
end;
---------
--創(chuàng)建事件日志表
create table errorlog
(
id number primary key,
errcode number,
errmsg varchar2(1024),
errdate date
)
--創(chuàng)建序列
create sequence seq_errorlog_id start with 1 increment by 1
--實(shí)驗(yàn)
declare
v_deptno dept.deptno%type := 10;
v_errcode number;
v_errmsg varchar2(1024);
begin
delete from dept where deptno = v_deptno;
commit;
exception
when others then
rollback;
v_errcode := SQLCODE;
v_errmsg := SQLERRM;
insert into errorlog values (seq_errorlog_id.nextval, v_errcode, v_errmsg, sysdate);
commit;
end;
--游標(biāo)
declare
cursor c is
select * from emp;
v_temp c%rowtype;
begin
open c;
fetch c into v_temp;
dbms_output.put_line(v_temp.ename);
close c;
end;
------------------
declare
cursor c is
select * from emp;
v_emp c%rowtype;
begin
open c;
loop
fetch c into v_emp;
exit when (c%notfound);
dbms_output.put_line(v_emp.ename);
end loop;
close c;
end;
----------------------
declare
cursor c is
select * from emp;
v_emp c%rowtype;
begin
open c;
fetch c into v_emp;
while (c%found) loop
dbms_output.put_line(v_emp.ename);
fetch c into v_emp;
end loop;
close c;
end;
-----------------
declare
cursor c is
select * from emp;
begin
for v_emp in c loop
dbms_output.put_line(v_emp.ename);
end loop;
end;
--帶參數(shù)的游標(biāo)
declare
cursor c (v_deptno emp.deptno%type, v_job emp.job%type)
is
select ename, sal from emp where deptno = v_deptno and job = v_job;
begin
for v_temp in c(30,'CLERK') loop
dbms_output.put_line(v_temp.ename);
end loop;
end;
--可更新的游標(biāo)
declare
cursor c
is
select * from emp2 for update;
begin
for v_temp in c loop
if (v_temp.sal < 2000) then
update emp2 set sal = sal * 2 where current of c;
elsif (v_temp.sal = 5000) then
delete from emp2 where current of c;
end if;
end loop;
commit;
end;
----------------
--存儲(chǔ)過(guò)程
create or replace procedure p
is
cursor c
is
select * from emp2 for update;
begin
for v_temp in c loop
if (v_temp.deptno = 10) then
update emp2 set sal = sal + 10 where current of c;
elsif (v_temp.deptno = 20) then
update emp2 set sal = sal + 20 where current of c;
else
update emp2 set sal = sal + 50 where current of c;
end if;
end loop;
commit;
end;
--執(zhí)行
exec p;
或
begin;
p;
end;
--帶參數(shù)的存儲(chǔ)過(guò)程
create or replace procedure p
(v_a in number, v_b number, v_ret out number, v_temp in out number)
is
begin
if (v_a > v_b) then
v_ret := v_a;
else
v_ret := v_b;
end if;
v_temp := v_temp + 1;
end;
--實(shí)驗(yàn)
declare
v_a number := 3;
v_b number := 4;
v_ret number;
v_temp number := 5;
begin
p(v_a, v_b, v_ret, v_temp);
dbms_output.put_line(v_ret);
dbms_output.put_line(v_temp);
end;
-------------------
--函數(shù)
create or replace function sal_tax
(v_sal number)
return number
is
begin
if (v_sal < 2000) then
return 0.10;
elsif (v_sal < 2750) then
return 0.15;
else
return 0.20;
end if;
end；
--觸發(fā)器
create table emp2_log
(
uname varchar2(20),
action varchar(10),
atime date
)
-----------
create or replace trigger trig
after insert or update or delete on emp2
begin
if inserting then
insert into emp2_log values (USER, 'insert', sysdate);
elsif updating then
insert into emp2_log values (USER, 'update', sysdate);
elsif deleting then
insert into emp2_log values (USER, 'delete', sysdate);
end if;
end;
----------
update emp2 set sal = sal * 2 where deptno = 30;
--------
create or replace trigger trig
after insert or update or delete on emp2 for each row
begin
if inserting then
insert into emp2_log values (USER, 'insert', sysdate);
elsif updating then
insert into emp2_log values (USER, 'update', sysdate);
elsif deleting then
insert into emp2_log values (USER, 'delete', sysdate);
end if;
end;
-------------
--不提倡使用
create or replace trigger trig
after update on dept for each row
begin
update emp2 set deptno = :NEW.deptno where deptno = :OLD.deptno;
end;
----------------------
--樹狀結(jié)構(gòu)的存儲(chǔ)與展現(xiàn)
drop table article;
create table article
(
id number primary key,
cont varchar2(4000),
pid number,
isleaf number(1), --0代表非葉子節(jié)點(diǎn)，1代表葉子節(jié)點(diǎn)
alevel number(2)
)
-------------
insert into article values (1, '螞蟻大戰(zhàn)大象', 0, 0, 0);
insert into article values (2, '大象被打趴下了', 1, 0, 1);
insert into article values (3, '螞蟻也不好過(guò)', 2, 1, 2);
insert into article values (4, '瞎說(shuō)', 2, 0, 2);
insert into article values (5, '沒(méi)有瞎說(shuō)', 4, 1, 3);
insert into article values (6, '怎么可能', 1, 0, 1);
insert into article values (7, '怎么沒(méi)可能', 6, 1, 2);
insert into article values (8, '可能性是很大的', 6, 1, 2);
insert into article values (9, '大象進(jìn)醫(yī)院了', 2, 0, 2);
insert into article values (10, '護(hù)士是螞蟻', 9, 1, 3);
commit;
---------
螞蟻大戰(zhàn)大象
大象被打趴下了
螞蟻也不好過(guò)
瞎說(shuō)
沒(méi)有瞎說(shuō)
大象進(jìn)醫(yī)院了
護(hù)士是螞蟻
怎么可能
怎么不可能
可能性是很大的
--------------------------
create or replace procedure p (v_pid article.pid%type, v_level binary_integer) is
cursor c is select * from article where pid = v_pid;
v_preStr varchar2(1024) := '';
begin
for i in 1..v_level loop
v_preStr := v_preStr || '****';
end loop;
for v_article in c loop
dbms_output.put_line(v_preStr || v_article.cont);
if (v_article.isleaf = 0)
then
p (v_article.id, v_level + 1);
end if;
end loop;
end;
總結(jié)
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