Oracle带输入输出参数的存储过程

原文链接：http://blog.itpub.net/29485627/viewspace-1248721/

（一）使用输入参数
需求：在emp_copy中添加一条记录，empno为已有empno的最大值+1，ename不能为空且长度必须大于0，deptno为60。
创建存储过程：
create or replace procedure insert_emp(emp_name in varchar2,dept_no in number) as
begin
declare max_empno number;
begin
if(emp_name is null or length(emp_name) = 0) then
return;
end if;

if(dept_no != 60) then
select max(empno) into max_empno from emp_copy;
insert into emp_copy(empno,ename,deptno) values(max_empno + 1,emp_name,dept_no);
end;
end insert_emp;
/
Procedure created.
调用存储过程并验证：
(1)
sql>execute insert_emp('Li Si',60);
PL/sql procedure successfully completed.
sql>
col empno format 99999;
col ename format a15;
col deptno format 99999;
select empno,deptno from emp_copy where deptno = 60;
EMPNO ENAME DEPTNO
------ --------------- ------
7981 Li Si 60
(2)
sql> execute insert_emp('',6);
sql> select empno,deptno from emp_copy where deptno = 6;
（二）使用输出参数
需求：在上个需求的基础上，要分别统计表emp_copy插入数据前后的记录数。
select count(1) into original_count from emp_copy;
select count(1) into current_count from emp_copy;
调用存储过程：
declare count1 number;
count2 number;
insert_emp('Wang Wu',60,count1,count2);
dbms_output.put_line('Original count of table emp_copy is ' || count1);
dbms_output.put_line('Current count of table emp_copy is ' || count2);
end;
Original count of table emp_copy is 15
Current count of table emp_copy is 16
（三）使用输入输出参数
in out参数综合了上述两种参数类型，既向过程体传值，也被赋值而传到过程体外。in out参数既可以用作输入也可以用作输出。
需求:实现两数交换。
create or replace procedure swap(value1 in out number,value2 in out number) as
value1 := value1 + value2;
value2 := value1 - value2;
value1 := value1 - value2;
end swap;
declare a number := 22;
b number := 33;
dbms_output.put_line('Before swap: a = ' || a || ',b = ' || b);
swap(a,b);
dbms_output.put_line('After swap: a = ' || a || ',Arial; line-height:26px">Before swap: a = 22,b = 33
After swap: a = 33,b = 22
PL/sql procedure successfully completed.

原文地址：https://www.jb51.cc/oracle/213080.html