串聯 - 名字和姓同列（甲骨文SQL）

Question

完全陌生的Oracle SQL，他這樣說：

試圖首先顯示作者的名和姓在同一列的「作者」與一起該作者編寫的書籍數量（按作者名字的升序排列）。

SELECT AUTHOR.FNAME || ' ' || AUTHOR.LNAME AS "Author", 
COUNT(BOOKAUTHOR.AUTHORID) AS "Books written" 
FROM BOOKS 
INNER JOIN BOOKAUTHOR ON BOOKS.ISBN = BOOKAUTHOR.ISBN 
INNER JOIN AUTHOR ON BOOKAUTHOR.AuthorID = AUTHOR.AuthorID 
ORDER BY AUTHOR.FNAME ASC 

併發似乎沒有工作，並與整體查詢有問題。

下面是與表：

書籍：ISBN，書名

作者：AUTHORID，LNAME，FNAME

BOOKAUTHOR：ISBN，AUTHORID

即使當我嘗試使用SELECT和FROM做一個簡單的連接時，它也不會顯示一個y結果。

例如像：

SELECT FNAME || ' ' || LNAME "AUTHOR NAME" 
FROM AUTHOR 

Answer 1

試試這個：

SELECT CONCAT(CONCAT(AUTHOR.FNAME, ' '), 
     AUTHOR.LNAME) AS "AUTHOR" 
COUNT(BOOKAUTHOR.AUTHORID) AS "Books written" 
FROM BOOKS 
INNER JOIN BOOKAUTHOR ON BOOKS.ISBN = BOOKAUTHOR.ISBN 
INNER JOIN AUTHOR ON BOOKAUTHOR.AuthorID = AUTHOR.AuthorID 
ORDER BY AUTHOR.FNAME ASC