（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 return; end if; 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; /
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, ename, deptno from emp_copy where deptno = 60; EMPNO ENAME DEPTNO ------ --------------- ------ 7981 Li Si 60
(2)
SQL> execute insert_emp(‘‘, 6); PL/SQL procedure successfully completed. SQL> select empno, ename, deptno from emp_copy where deptno = 6; SQL>
（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。
创建存储过程：
create or replace procedure insert_emp(emp_name in varchar2, dept_no in number, original_count out number, current_count out 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 return; end if; select count(1) into original_count from emp_copy; select max(empno) into max_empno from emp_copy; insert into emp_copy(empno, ename, deptno) values(max_empno + 1, emp_name, dept_no); select count(1) into current_count from emp_copy; end; end insert_emp; /
调用存储过程：
declare count1 number; count2 number; begin 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 PL/SQL procedure successfully completed.
（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。
创建存储过程：
create or replace procedure swap(value1 in out number, value2 in out number) as begin value1 := value1 + value2; value2 := value1 - value2; value1 := value1 - value2; end swap; /
调用存储过程：
declare a number := 22; b number := 33; begin dbms_output.put_line(‘Before swap: a = ‘ || a || ‘, b = ‘ || b); swap(a, b); dbms_output.put_line(‘After swap: a = ‘ || a || ‘, b = ‘ || b); end; / Before swap: a = 22, b = 33 After swap: a = 33, b = 22 PL/SQL procedure successfully completed.
原文：https://www.cnblogs.com/xwb583312435/p/9054731.html