2013-11-11 Oracle 课堂测试 练习题 例：BULK COLLECT及return table

--1)  查询“计算机”专业学生在“2007-12-15”至“2008-1-8”时间段内借书的
--学生编号、学生名称、图书编号、图书名称、借出日期；
select s.stuid, s.stuname, b.bid, b.title, bo.t_time
  from borrow bo
  join student s on bo.stuid = s.stuid
  join book b on bo.bid = b.bid
 where bo.t_time between to_date('2007-12-15', 'yyyy-mm-dd') and
       to_date('2008-01-08', 'yyyy-mm-dd') and s.major = '计算机';

--2)  用pl/sql匿名块实现，查询所有借过图书的学生编号、学生名称、专业；（提示：用游标）
declare
  cursor c_student is
    select * from student;
  cursor c_borrow is
    select * from borrow;
begin
  dbms_output.put_line('学生编号  ' || '  学生姓名  ' || '  专业');
  for v_student in c_student loop
    for v_borrow in c_borrow loop
      if v_student.stuid = v_borrow.stuid then
        dbms_output.put_line(v_student.stuid || '        ' ||
                             v_student.stuname || '        ' ||
                             v_student.major);
        exit;
      end if;
    end loop;
  end loop;
end;

--3)  查询借过作者为“安意如”的图书的学生姓名、图书名称、借出日期、归还日期；
select s.stuname, b.title, bo.t_time, bo.b_time
  from borrow bo
  join student s on bo.stuid = s.stuid
  join book b on bo.bid = b.bid
 where b.author = '安意如';

--4)   查询目前借书但未归还图书的学生名称及未还图书数量；
--（要求： 未还图书数，用函数实现，并在sql语句中调用）
create or replace type t_borrowlist_object as object(stuid varchar2(20),
                                                     books number);
create or replace type t_borrowlist_table as table of t_borrowlist_object;

create or replace function f_borrowlist
  return t_borrowlist_table is v_rs t_borrowlist_table;
begin

  select t_borrowlist_object(s.stuname, count(*)) BULK COLLECT
    INTO v_rs
    from borrow bo
    join student s on bo.stuid = s.stuid
    join book b on bo.bid = b.bid
   where bo.b_time is null
   group by s.stuname;

  return v_rs;
end;

select * from table(f_borrowlist());

--5）用一个存储过程完成还书功能，输入参数为学号和书号，把当前日期作为还书日期。
create or replace function f_rebook(v_stuid student.stuid%type,
                                    v_bid   book.bid%type) return varchar2 is
  PRAGMA AUTONOMOUS_TRANSACTION;
  v_flag     number;
  v_borrowid borrow.borrowid%type;
  v_rs       varchar2(200);
begin

  select count(*)
    INTO v_flag
    from borrow
   where b_time is null
     and stuid = v_stuid
     and bid = v_bid;

  if v_flag >= 1 then
    select borrowid
      INTO v_borrowid
      from borrow
     where b_time is null
       and stuid = v_stuid
       and bid = v_bid
       and rownum <= 1;
    v_rs := v_stuid || ' 号同学还 ' || v_bid || ' 图书 成功';
    update borrow set b_time = sysdate where borrowid = v_borrowid;
    commit;
  else
    v_rs := v_stuid || ' 号同学还 ' || v_bid || ' 图书 失败';
  end if;

  return v_rs;
end;

select * from borrow;

select f_rebook('1001', 'B001') from dual;