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正确及错误的"PL/SQL"对照使用示例：
/**
关于正确及错误PL/SQL对照使用的示例
*/
create table test(tid int primary key not null,tname varchar2(50));
create sequence test_seq start with 1 increment by 1;
insert into test values(test_seq.nextval,'FLB');
insert into test values(test_seq.nextval,'FLB1');
---------------------------------
--错误函数1
create or replace function f
return int
begin
return 5*5;
end;
--错误函数2
create or replace function f()
return number
is
begin
return 5*5;
end;
--错误函数3
create or replace function f
return number
begin
return 5*5;
end;
--该函数的正确函数1
create or replace function f
return number
is
begin
return 5*5;
end;
--该函数的正确函数2
create or replace function f
return int
is
begin
return 5*5;
end;
------------------------------------
--正确函数
create or replace function f5
(pid number)
return varchar2
is
rname varchar2(50);
cursor cname
is
select tname from test where tid=pid;
begin
open cname;
fetch cname into rname;
return rname;
end;
--调用函数用call出错
call f5(2);
--调用出错，函数必须有值的接收者
begin
f5(2);
end;
--这种方法调用不正确
declare
r varchar2;
begin
r:=f5(2);
dbms_output.put_line(r);
end;
--这种方法调用正确
begin
dbms_output.put_line(f5(2));
end;
--这种方法调用正确
declare
r varchar2(50);
begin
r:=f5(2);
dbms_output.put_line(r);
end;
--正确函数
create or replace function f4
(ttid in integer)
return varchar2
is
rname varchar(50);
cursor cname
is
select tname from test where tid=ttid;
begin
open cname;
fetch cname into rname;
return rname;
end;
--正确函数
create or replace function f7
(n in number)
return number
is
begin
return n*n;
end f7;
------------------------------------------
--过程
create or replace procedure p1
is
begin
dbms_output.put_line('First Procuder');
end p1;
--调用过程用call不会出错
call p1();
--这种方法调用过程不正确
begin
dbms_output.put_line(p1());
end;
----------注意函数与过程的调用的不同处----------
------------------------------------------------
--错误过程
create or replace procedure p3
(ttid in Integer)
is
rname varchar;
cursor cname
is
select tname from test where tid=ttid;
begin
open cname;
fetch cname into rname;
dbms_output.put_line(rname);
end;
--正确过程
create or replace procedure p3
(ttid in Integer)
is
rname varchar(50);
cursor cname
is
select tname from test where tid=ttid;
begin
open cname;
fetch cname into rname;
dbms_output.put_line(rname);
end; | |
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