您应该从 Publications 表中删除作者,并制作一个将用户与 Publications 链接的第三个表。
PublicationAuthors
PublicationID int
UserID int
然后您的查询可以只检查该表以查看用户是否与发布相关联。此外,您可以根据需要拥有尽可能多的作者,而无需向 Publications 添加新列,并且如果有人更改其姓名,也不会破坏与 Publications 的关系。
这是一个示例(我为此使用了 SQL Server,因此可能存在小的语法差异):
CREATE TABLE Publications(
[PublicationID] [int] IDENTITY(1,1) NOT NULL,
[Title] [nvarchar](128) NOT NULL,
[DatePublished] [DateTime]
PRIMARY KEY CLUSTERED
(
[PublicationID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
CREATE TABLE Authors(
[AuthorID] [int] IDENTITY(1,1) NOT NULL,
[FirstName] [nvarchar](128) NOT NULL,
[LastName] [nvarchar](128) NOT NULL
PRIMARY KEY CLUSTERED
(
[AuthorID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
CREATE TABLE PublicationAuthors(
[PublicationID] [int],
[AuthorID] [int]
PRIMARY KEY CLUSTERED
(
[PublicationID] ASC,
[AuthorID]
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
INSERT INTO Publications (Title, DatePublished) VALUES ('Sphere', '5/12/1987')
INSERT INTO Publications (Title, DatePublished) VALUES ('Jurassic Park', '11/1/1990')
INSERT INTO Authors (FirstName, LastName) VALUES ('Michael', 'Chricton')
INSERT INTO Authors (FirstName, LastName) VALUES ('Andy', 'McKenna')
INSERT INTO PublicationAuthors (PublicationID, AuthorID) VALUES (1, 1)
INSERT INTO PublicationAuthors (PublicationID, AuthorID) VALUES (2, 1)
INSERT INTO PublicationAuthors (PublicationID, AuthorID) VALUES (2, 2)
--All Authors for this Publication
SELECT p.Title, p.DatePublished, a.FirstName, a.LastName
FROM Publications p
INNER JOIN PublicationAuthors pa
ON pa.PublicationID = p.PublicationID
INNER JOIN Authors a
ON a.AuthorID = pa.AuthorID
WHERE p.PublicationID = 2
--All Publications for this Author
SELECT p.Title, p.DatePublished, a.FirstName, a.LastName
FROM Authors a
INNER JOIN PublicationAuthors pa
ON pa.AuthorID = a.AuthorID
INNER JOIN Publications p
ON pa.PublicationID = p.PublicationID
WHERE a.AuthorID = 1
然后,当您意识到我拼错了作者的姓氏时,您只需更新那一行,而无需触及 Publications 表。