选择逗号分隔值sql存储过程[重复]

Question

我有三张桌子：

1. book_shelf -> pkid 等列

2. book_author -> pkid,fkid_book_shelf,fkid_author

3. author -> pkid,name等

对于book_shelf 中的一行，希望将作者姓名以逗号分隔。如果书架实体有两个作者，则在book_author 表中插入两行。

这是我尝试过的

(select BookShelf.pkid as SrNo,stuff((select ',' + a.name
    from 
    lib.book_shelf bs inner join
    lib.book_author ba on bs.pkid=ba.fkid_book_shelf
    inner join lib.author a on a.pkid=ba.fkid_authors 
    for xml path ('')
), 1, 1, '') as Author from lib.book_shelf BookShelf)

但它会为每个 book_shelf 行选择所有作者姓名。

Answer 1

希望这对你有帮助。

CREATE TABLE BookShelf(ID INT)
CREATE TABLE BookAuthor(ID INT, BookShelf INT, AuthorID INT)
CREATE TABLE Author(ID INT, Name VarChar(50))
GO

INSERT INTO BookShelf VALUES(1)
INSERT INTO BookShelf VALUES(2)

INSERT INTO Author VALUES(1,'Author1')
INSERT INTO Author VALUES(2,'Author2')
INSERT INTO Author VALUES(3,'Author3')
INSERT INTO Author VALUES(4,'Author4')


INSERT INTO BookAuthor VALUES(1,1,1)
INSERT INTO BookAuthor VALUES(1,1,2)
INSERT INTO BookAuthor VALUES(1,2,3)
INSERT INTO BookAuthor VALUES(1,2,4)

SELECT 
    BookShelf.ID, 
    STUFF((SELECT ',' + Author.Name FROM BookAuthor INNER JOIN Author ON BookAuthor.AuthorID = Author.ID WHERE BookAuthor.BookShelf = BookShelf.ID FOR XML PATH('')),1,1,'')
FROM 
    BookShelf