PLSQL 在发布者表中添加新发布者，然后将其添加到发布者值为空的图书表中并以给定格式显示答案

【问题标题】：PLSQL Adding new publisher in publisher table and then adding it to book table where publisher value is null and Displaying it in the given formatPLSQL 在发布者表中添加新发布者，然后将其添加到发布者值为空的图书表中并以给定格式显示
【发布时间】：2021-06-22 03:09:10
【问题描述】：

我正在尝试编写一个 PLSQL 块来显示书籍及其作者和出版商的详细信息。问题陈述如下：

将新发布者“ttk publisher”插入发布者表。
在 book 表中为出版商值为空的记录分配此新值。
以以下格式检索新更新的新记录（使用字符串函数仅显示“标题”列的前 10 个字母）

输出格式如下：

BOOKID.............TITLE.............publisher.............Author

639163050...........10 Years o...........Prentice Hall...........Paul Deitel    
330895717...........African Fo...........Prentice Hall...........Tem Nieto

架构详情如下

1.author- authorid, firstname, lastname

2.book- author_id, bookid, publisherid, title

3.publisher- publisherid, publishername

【问题讨论】：

标签： sql oracle plsql

【解决方案1】：

应该是这样的。在代码中读取 cmets。

declare
  l_publisherid   publisher.publisherid%type;
begin
  -- 1. You didn't say how PUBLISHER.PUBLISHER_ID gets its value,
  -- so I'll presume that it is automatically generated, somehow
  -- (identity column or a database trigger)
  insert into publisher (publishername) values ('ttk publisher')
    returning publisherid into l_publisherid;
  
  -- 2. 
  update book b set
    b.publisherid = l_publisherid
    where b.publisherid is null;

  -- 3. Join all 3 tables on appropriate columns. Use a loop to
  -- display ALL books involved. WHERE clause is used to retrieve
  -- books whose PUBLISHERID has just been updated
  for cur_r in 
    (select b.bookid, 
            substr(b.title, 1, 10) title, 
            p.publishername publisher, 
            a.firstname ||' '|| a.lastname author
     from book b join publisher p on p.publisherid = b.publisherid
     join author a on a.authorid = b.author_id
     where p.publisherid = l_publisherid
    )
  loop
    dbms_output.put_line(cur_r.bookid    ||'...'||
                         cur_r.title     ||'...'||
                         cur_r.publisher ||'...'||
                         cur_r.author);
  end loop;                         
end;
/

【讨论】：

嗨，谢谢，我尝试运行相同的代码，但它给出了一个错误 ~ 在标准输出上没有响应 ~
好吧，如果您发布了正确的测试用例（CREATE TABLE 和 INSERT INTO 语句），我/我们可以对其进行测试。另外，你用什么工具？您是否启用 dbms_output？
我在hackerrank上运行它
对不起，我不知道它是怎么操作的，没用过。

【解决方案2】：

这就是hackerrank的工作方式：

      set serveroutput on
    
    declare
    l_publisherid publisher.publisherid%type;
    begin
    
        insert into publisher values (123, 'TTK Publisher')
        returning publisherid into l_publisherid;
           
        update book b set b.publisherid=l_publisherid
        where b.publisherid is null;
    
      declare
    
      cursor c is
    
        select * from book b
    left join author on authorid=author_id
    left join publisher p on b.publisherid=p.publisherid
    where p.publisherid=l_publisherid;
    
    
     begin
        dbms_output.put_line('BOOKID'||'.............'||'TITLE'||'.............'||'publisher'||'.............'||'Author');
    
      for i in c loop
       dbms_output.put_line(i.bookid||'...........'||substr(i.title,1,10)||'...........'||i.publishername||'...........'||concat(i.firstname||' ',i.lastname));
        end loop;
        END;
END;
/

【讨论】：