Oracle概念：过程、函数、程序包

核心提示： procedure foo(p1 varchar2, p2 varchar2);但是：只在参数名称、输入输出模式、或者返回类型上不同，是不够的，Oracle概念：过程、函数、程序包(9)，比如procedure foo(p1 varchar2);procedure foo(p2 varch

procedure foo(p1 varchar2, p2 varchar2);

但是：只在参数名称、输入输出模式、或者返回类型上不同，是不够的。比如

procedure foo(p1 varchar2);

procedure foo(p2 varchar2);

procedure foo(p1 in varchar2);

procedure foo(p1 in out varchar2);

例如

desc dbms_output

试验：重载SWAP()

之前的例子：

create or replace

procedure swap(

p1 in out number,

p2 in out number ) as

---

l_temp number;

begin

l_temp := p1;

p1 := p2;

p2 := l_temp;

end swap;

/

该例子只能实现交换数值，我们将其包装，并进行重载，使其也可以交换varchar2 和 date

(1) 建立规范

create or replace package utilities as

procedure swap(p1 in out number, p2 in out number);

procedure swap(p1 in out varchar2,p2 in out varchar2);

procedure swap(p1 in out date,p2 in out date);

end utilities;

/

(2) 建立主体

create or replace package body utilities as

procedure swap(p1 in out number, p2 in out number ) as

l_temp number;

begin

dbms_output.put_line(‘Swapping number’);

l_temp := p1;

p1 := p2;

p2 := l_temp;

end swap;

procedure swap(p1 in out varchar2,p2 in out varchar2) as

l_temp varchar2(32767);

begin

dbms_output.put_line(‘Swapping varchar2’);

l_temp := p1;

p1 := p2;