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;