接plsql一文
--游标cursor，结果集上的指针
[sql]
declare
cursor c is
select * from emp;--只是声明游标，还未取数据
v_emp c%rowtype
begin
open c;
fetch c into v_emp;
dbms_output.put_line(v_emp.ename);
close c;
end;
declare
cursor c is
select * from emp;
v_emp c%rowtype;
beigin
open c;
loop
fetch c into v_emp;
exit when (c%notfound);
dbms_output.put_line(v_emp.ename);
end loop;
close c;
end;
--带参数的游标
[sql]
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;
--可更新的游标
[sql]
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;
else if (v_temp.sal = 5000) then
delete from emp2 where current of c;
end if;
end loop;
commit;
end;
--创建存储过程，带有名字的PL/SQL块
[sql]
grant create procedure to shijin;
create or replace procedure p
is
cursor c is
select * from emp2 for update;
begin
for v_emp in c loop
if(v_emp.deptno = 10) then
update emp2 set sal = sal + 10 where current of c;
else if (v_emp.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 loop;
begin
p;
end;
或者
exec p;
--带参数的存储过程，默认是in
[sql]
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;
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;
--函数
[sql]
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;
select sal_tax(sal) from emp;
--触发器！！！！牢牢掌握概念
[sql]
create table emp2_log
(
uname varchar2(20),
action varchar2(10),
atime date
);
grant create triger to shijin;
create or replace trigger trig
after insert or delete or update on emp2 --此处可以加上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;
update emp2 set sal = sal*2 where deptno = 30;
drop trigger trig;
create or replace trigger trig
after update on dept
for each row
begin
update emp set deptno = :NEW.deptno where deptno = :OLD.deptno;
end;
--树状结构数据的存储与显示
[sql]
drop table article;
create table article
(
id number primary key,
cont varchar2(4000),
pid number,
isleaf number(1),--0代表非叶子节点，1代表叶子节点
alevel number(2)
)
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_articel.id,v_level + 1);
end if;
end loop;
end;
insert into article values (1,'蚂蚁大战大象',0,0,0);
insert into article values (2,'大象被打趴下',1,0,1);
insert into article values (3,'蚂蚁也不好过',2,1,2);
insert into article values (4,'瞎 说',2,0,2);
insert into article values (5,'没 有 瞎 说',4,1,3);
insert into article values (6,'怎 么 可 能',1,0,1);
insert into article values (7,'怎么没有可能',6,1,2);
insert into article values (8,'可能性很大的',6,1,2);
insert into article values (9,'大象进医院了',2,0,2);
insert into article values (10,'护士是蚂蚁',9,1,3);
begin
p(0,0);
end;
show error;
--展示emp的树状结构
