Oracle笔记 十、PL/SQL存储过程

--create or replace 创建或替换，如果存在就替换，不存在就创建

create or replace procedure p

is

  cursor c

  is

  select * from dept2 for update;

begin

  for row_record in c loop

    if (row_record.deptno = 30) then

      update dept2 set dname = substr(dname, 0, length(dname) - 3) where current of c;

    end if;

  end loop;

end;

exec p;

begin

p;

end;

--带参存储过程

--in 输入参数，不带in out 默认输入参数

--out 输出参数

--in out 同时带的是输入输入参数

create or replace procedure p2(

       a in number,

       b number,

       s_result out number,

       s_temp in out number

  )

is

begin

  if (a > b) then

    s_result := a;

  else

    s_result := b;

  end if;

  s_temp := s_temp + 3;

end;

--调用存储过程

declare

  v_a number := 4;

  v_b number := 6;

  v_result number;

  v_temp number := 5;

begin

  p2(v_a, v_b, v_result, v_temp);

  dbms_output.put_line(v_a);

  dbms_output.put_line(v_b);

  dbms_output.put_line(v_result);

  dbms_output.put_line(v_temp);

end;

---删除一个表的过程

create or replace procedure drop_table(tname varchar2)

as

  total int := 0;

begin

     select count(*) into total from user_tables 

            where table_name = upper(tname);

     if total >= 1 then

        execute immediate ‘drop table ‘||tname; --此处必须用动态sql

     end if;

end;

select * from user_tables;

--递归存储过程

create or replace procedure pro_emp(sEmpno emp.empno%type, sLevel integer)

is

       cursor c is select * from emp where mgr = sEmpno;

       prefixStr varchar(255);

begin

  for i in 1..sLevel loop

    prefixStr := prefixStr || ‘----‘;

  end loop;

  for row_data in c loop

    dbms_output.put_line(prefixStr || row_data.ename);

    pro_emp(row_data.empno, sLevel + 1);

  end loop;

end;

select * from emp;

begin

  pro_emp(7839, 0);

end;