Question

我在MySQL数据库中有两个表：

Book(title, publisher, year) title is primary key

Author(name, title) title is foreign key to Book

我试图从2000年到2005年（包括每年）选择每年出版一本书的作者的名字。这个SQL查询有效，但有没有办法可以在需要时更容易更改日期范围？

SELECT DISTINCT name
FROM Author
WHERE name IN  (SELECT Author.name 
                FROM Author INNER JOIN Book ON (Author.title = Book.title) 
                WHERE year = 2000)
        AND name IN
                (SELECT Author.name 
                FROM Author INNER JOIN Book ON (Author.title = Book.title)
                WHERE year = 2001)
        AND name IN
                (SELECT Author.name 
                FROM Author INNER JOIN Book ON (Author.title = Book.title)
                WHERE year = 2002)
        AND name IN
                (SELECT Author.name 
                FROM Author INNER JOIN Book ON (Author.title = Book.title)
                WHERE year = 2003)
        AND name IN
                (SELECT Author.name 
                FROM Author INNER JOIN Book ON (Author.title = Book.title)
                WHERE year = 2004)
        AND name IN
                (SELECT Author.name 
                FROM Author INNER JOIN Book ON (Author.title = Book.title)
                WHERE year = 2005);

Answer 1

我会在where语句中加上'OR'子句。这取决于你的表的设置方式，但它应该有效：

SELECT DISTINCT name
FROM Author
     WHERE name IN  (SELECT Author.name 
                     FROM Author INNER JOIN Book ON (Author.title = Book.title) 
                     WHERE year = 2000)

Answer 2

像这样的东西，我没有测试它，但你可以分组并只选择那些有6行的那些：

SELECT a.name FROM Author a
INNER JOIN Book b
   ON a.title = b.title
WHERE b.year BETWEEN 2000 AND 2005
 GROUP BY name HAVING COUNT(a.name) = 6

Answer 3

我会使用参数

declare @StartYear int = 2000
declare @EndYear int = 2005

select a.name 
from author a
inner join book b on a.title = b.title
where year between @StartDate and @EndDate 
group by a.name
having count(distinct year) = @EndDate- @StartDate

每当您输入

时，都可以轻松修改和修改

Answer 4

以下是两种方法，以及由于细微的错误导致另一种方法出错。

SQL Fiddle

MySQL 5.5.32架构设置：

create table Book (title varchar(10), year int) ;
create table Author (name varchar(10), title varchar(10));

insert Book values 
('Book1',2000),('Book2',2000),
('Book3',2000),('Book4',2000),
('Book5',2000),('Book6',2000),
('Book7',2001),('Book8',2002),
('Book9',2003),('Book10',2004),
('Book11',2005);

insert into Author values 
('Author1','Book1'),('Author1','Book2'),
('Author1','Book3'),('Author1','Book4'),
('Author1','Book5'),('Author1','Book6'),
('Author2','Book6'),('Author2','Book7'),
('Author2','Book8'),('Author2','Book9'),
('Author2','Book10'),('Author2','Book11');

# author1 has written 6 books in one year
# author2 has written 1 book in every of the six years

查询1 ：

# incorrect as it matches author1 who has 6 books in a single year
SELECT name from Author 
INNER JOIN BOOK on Author.title = Book.Title 
WHERE year IN (2000,2001,2002,2003,2004,2005) 
GROUP BY name 
HAVING COUNT(name) = 6

<强> Results ：

|    NAME |
|---------|
| Author1 |
| Author2 |

查询2 ：

# correct as it counts distinct years
SELECT name from Author 
INNER JOIN BOOK on Author.title = Book.Title 
WHERE year IN (2000,2001,2002,2003,2004,2005) 
GROUP BY name 
HAVING COUNT(DISTINCT year) = 6

<强> Results ：

|    NAME |
|---------|
| Author2 |

查询3 ：

# correct using relational division
SELECT DISTINCT name
FROM Author A1
INNER JOIN Book B1 ON A1.title = B1.Title
WHERE NOT EXISTS (
    SELECT * 
    FROM Book B2
    WHERE year IN (2000,2001,2002,2003,2004,2005) 
    AND NOT EXISTS (
       SELECT *
       FROM Author A2
       INNER JOIN Book B3 ON A2.title = B3.Title
       WHERE (A1.name = A2.name)
        AND (B3.year = B2.year)
    )
)

<强> Results ：

|    NAME |
|---------|
| Author2 |

SQL查询：如何改进？

4 个答案: