如何加入我的結果以檢索另一個表的相應記錄？

Question

(SELECT BOOKAUTHOR from (select DISTINCT bookauthor, genre from BOOK) group by bookauthor HAVING COUNT(*) > 1);

對連接很困惑

請讓我知道是否有任何方法可以改善我的問題，我已經嘗試過搜索和搜索，但仍然很困惑如何做到這一點

Answer 1

你會做類似的事情

SELECT a.AUTHORFIRSTNAME,
       a.AUTHORLASTNAME
  FROM (SELECT BOOKAUTHOR, COUNT(*)
          FROM BOOK
          GROUP BY BOOKAUTHOR
          HAVING COUNT(*) > 1) b
  INNER JOIN AUTHOR a
    ON a.AUTHORID = b.BOOKAUTHOR

dbfiddle在這里