Question

我正在尝试创建一个查询，列出同一作者的所有书籍。大多数列表只有一本作者的书，但我希望在db中列出多本书的作者为该作者显示这些书。

我有两张桌子：

预订 - AuthorID, BkTitle等
作者 - AuthorID, AuthFName, AuthLName

我希望结果按AuthLName排序，报告包含db中具有相同authorid的任何书籍。

想要的结果示例：

 AUTHORID BKTITLE           AUTHFNAME     AUTHLNAME
--------- ----------------- ------------  -----------
    504   KNIGHT FREEDOM     Chris        Feehan
    504   KNIGHT SHOWDOWN    Chris        Feehan

目前，我有以下代码：

select AUTHORID, BKTITLE
from BOOK 
where AUTHORID in
    (select AUTHORID from
       (select AUTHORID, 
               count(*) as BOOK_COUNT
        from BOOK
        group by AUTHORid
        order by AUTHORid )
     where BOOK_COUNT >= 2);

给出：

  AUTHORID BKTITLE
---------- --------------------
       504 KNIGHT FREEDOM
       504 KNIGHT SHOWDOWN

我需要找到一种方法从作者表中获取信息并将其添加到其中。

Answer 1

这应该做：

SELECT b.AUTHORID, b.BKTITLE, a.AUTHFNAME, a.AUTHLNAME
FROM BOOK b
  INNER JOIN AUTHOR a
    ON b.AUTHORID = a.AUTHORID
AND b.AUTHORID IN
(
  SELECT AUTHORID
  FROM BOOK
  GROUP BY AUTHORID
  HAVING COUNT(AUTHORID) > 1
)
ORDER BY a.AUTHLNAME, a.AUTHFNAME

Answer 2

这个怎么样 - 更新为首先使用CTE（公用表表达式）来确定哪些作者在数据库表BOOK中有多本书，然后仅列出那些作者及其书籍：

;WITH AuthorsWithMoreThanOneBook AS
(
    SELECT AUTHORID, BOOK_COUNT = COUNT(*)
    FROM BOOK
    GROUP BY AUTHORID
    HAVING BOOK_COUNT > 1)
)
SELECT
    b.AUTHORID, b.BKTITLE, a.AuthFName, a.AuthLName
FROM
    BOOK b
INNER JOIN
    AUTHOR a ON b.AuthorID = a.AuthorID
INNER JOIN 
    AuthorsWithMoreThanOneBook A2 ON a.AuthorID = A2.AuthorID
ORDER BY
    a.AuthLName, a.AuthFName

更新：好的，您正在使用Oracle ....不确定（多年没有使用过它） - 但是您不能只是将原始查询扩展为以下内容：< / p>

select bk.AUTHORID, bk.BKTITLE, a.AUTHORFNAME, a.AUTHORLNAME
from BOOK AS bk
INNER JOIN AUTHOR AS a ON a.AUTHORID = bk.AUTHORID
where bk.AUTHORID in
    (select AUTHORID from
       (select AUTHORID, 
               count(*) as BOOK_COUNT
        from BOOK
        group by AUTHORid
        order by AUTHORid )
     where BOOK_COUNT >= 2);

不确定Oracle是否支持这些表别名（BOOK AS bk） - 但我很确定它确实以某种方式支持它....

Answer 3

只需对每个表进行一次访问即可执行此操作：

SELECT * FROM
(
  SELECT AuthorID, BkTitle, AuthFName, AuthLName
        ,COUNT(*) OVER (PARTITION BY AuthorID)
         AS c
  FROM BOOK
  JOIN AUTHOR USING (AuthorID)
)
WHERE c > 1;

SQL Query需要从两个单独的表中获取信息

3 个答案: