SQL中的循环行

我正在寻找如下输出：

[最近]日期：评论，[第二最近]日期：评论

例如：

Book    Comments
BookA   27/03/13: comment1, 21/03/13: comment2, 21/03/13: uhuuuu [and so on]
BookB   21/03/13: comment2a, 18/03/13: xxx comments

MS SQL Server 2012架构设置：

CREATE TABLE books 
    (
     book varchar(10), 
     comments varchar(20),
     datewww datetime

    );

INSERT INTO books
(book, comments, datewww)
VALUES
('BookA', 'comment1', '2013-03-27 10:30:00.000'),
('BookA', 'comment2', '2013-03-21 09:31:00.000'),
('BookA', 'comentx', '2013-03-10 08:31:00.000'),
('BookA', 'Text test', '2013-02-15 07:41:00.000'),
('BookA', 'uhuuuu', '2013-03-21 07:31:00.000'),
('BookB', 'comment2a', '2013-03-21 09:31:00.000'),
('BookB', 'xxx comments', '2013-03-18 09:31:00.000');

SELECT
  book,
  CONVERT(VARCHAR, datewww, 3) + ': ' + comments + ', '
FROM books

|  BOOK |                 COLUMN_1 |
|-------|--------------------------|
| BookA |     27/03/13: comment1,  |
| BookA |     21/03/13: comment2,  |
| BookA |      10/03/13: comentx,  |
| BookA |    15/02/13: Text test,  |
| BookA |       21/03/13: uhuuuu,  |
| BookB |    21/03/13: comment2a,  |
| BookB | 18/03/13: xxx comments,  |

|  BOOK |                                                                                          comments |
|-------|--------------------------------------------------------------------------------------------------|
| BookA | 27/03/13: comment1, 21/03/13: comment2, 21/03/13: uhuuuu, 10/03/13: comentx, 15/02/13: Text test |
| BookB | 21/03/13: comment2a, 18/03/13: xxx comments |

查询1：

CREATE TABLE books 
    (
     book varchar(10), 
     comments varchar(20),
     datewww datetime

    );

INSERT INTO books
(book, comments, datewww)
VALUES
('BookA', 'comment1', '2013-03-27 10:30:00.000'),
('BookA', 'comment2', '2013-03-21 09:31:00.000'),
('BookA', 'comentx', '2013-03-10 08:31:00.000'),
('BookA', 'Text test', '2013-02-15 07:41:00.000'),
('BookA', 'uhuuuu', '2013-03-21 07:31:00.000'),
('BookB', 'comment2a', '2013-03-21 09:31:00.000'),
('BookB', 'xxx comments', '2013-03-18 09:31:00.000');

SELECT
  book,
  CONVERT(VARCHAR, datewww, 3) + ': ' + comments + ', '
FROM books

|  BOOK |                 COLUMN_1 |
|-------|--------------------------|
| BookA |     27/03/13: comment1,  |
| BookA |     21/03/13: comment2,  |
| BookA |      10/03/13: comentx,  |
| BookA |    15/02/13: Text test,  |
| BookA |       21/03/13: uhuuuu,  |
| BookB |    21/03/13: comment2a,  |
| BookB | 18/03/13: xxx comments,  |

|  BOOK |                                                                                          comments |
|-------|--------------------------------------------------------------------------------------------------|
| BookA | 27/03/13: comment1, 21/03/13: comment2, 21/03/13: uhuuuu, 10/03/13: comentx, 15/02/13: Text test |
| BookB | 21/03/13: comment2a, 18/03/13: xxx comments |

：

CREATE TABLE books 
    (
     book varchar(10), 
     comments varchar(20),
     datewww datetime

    );

INSERT INTO books
(book, comments, datewww)
VALUES
('BookA', 'comment1', '2013-03-27 10:30:00.000'),
('BookA', 'comment2', '2013-03-21 09:31:00.000'),
('BookA', 'comentx', '2013-03-10 08:31:00.000'),
('BookA', 'Text test', '2013-02-15 07:41:00.000'),
('BookA', 'uhuuuu', '2013-03-21 07:31:00.000'),
('BookB', 'comment2a', '2013-03-21 09:31:00.000'),
('BookB', 'xxx comments', '2013-03-18 09:31:00.000');

SELECT
  book,
  CONVERT(VARCHAR, datewww, 3) + ': ' + comments + ', '
FROM books

|  BOOK |                 COLUMN_1 |
|-------|--------------------------|
| BookA |     27/03/13: comment1,  |
| BookA |     21/03/13: comment2,  |
| BookA |      10/03/13: comentx,  |
| BookA |    15/02/13: Text test,  |
| BookA |       21/03/13: uhuuuu,  |
| BookB |    21/03/13: comment2a,  |
| BookB | 18/03/13: xxx comments,  |

|  BOOK |                                                                                          comments |
|-------|--------------------------------------------------------------------------------------------------|
| BookA | 27/03/13: comment1, 21/03/13: comment2, 21/03/13: uhuuuu, 10/03/13: comentx, 15/02/13: Text test |
| BookB | 21/03/13: comment2a, 18/03/13: xxx comments |

：

CREATE TABLE books 
    (
     book varchar(10), 
     comments varchar(20),
     datewww datetime

    );

INSERT INTO books
(book, comments, datewww)
VALUES
('BookA', 'comment1', '2013-03-27 10:30:00.000'),
('BookA', 'comment2', '2013-03-21 09:31:00.000'),
('BookA', 'comentx', '2013-03-10 08:31:00.000'),
('BookA', 'Text test', '2013-02-15 07:41:00.000'),
('BookA', 'uhuuuu', '2013-03-21 07:31:00.000'),
('BookB', 'comment2a', '2013-03-21 09:31:00.000'),
('BookB', 'xxx comments', '2013-03-18 09:31:00.000');

SELECT
  book,
  CONVERT(VARCHAR, datewww, 3) + ': ' + comments + ', '
FROM books

|  BOOK |                 COLUMN_1 |
|-------|--------------------------|
| BookA |     27/03/13: comment1,  |
| BookA |     21/03/13: comment2,  |
| BookA |      10/03/13: comentx,  |
| BookA |    15/02/13: Text test,  |
| BookA |       21/03/13: uhuuuu,  |
| BookB |    21/03/13: comment2a,  |
| BookB | 18/03/13: xxx comments,  |

|  BOOK |                                                                                          comments |
|-------|--------------------------------------------------------------------------------------------------|
| BookA | 27/03/13: comment1, 21/03/13: comment2, 21/03/13: uhuuuu, 10/03/13: comentx, 15/02/13: Text test |
| BookB | 21/03/13: comment2a, 18/03/13: xxx comments |

---

您最好在应用程序逻辑中这样做，而不是在SQL查询中这样做。本质上，我正在寻找的是在SQL中重复执行此操作。实际上，我是在应用程序逻辑中这样做的。谢谢。SQLFiddle是一个很好的工具，在使用它发帖方面做得很好。如果您使用run按钮上的箭头选择markdown输出，这会更好，它将代码格式化为可以直接粘贴到问题中的格式，并包含所有正确的格式和链接。这样，用户在不访问外部站点的情况下更容易看到您的问题，而且该链接将来可能会腐烂或不可用。太棒了。我不知道。谢谢你的帮助，这会让你的帖子对用户更具吸引力。如果有机会，请与其他用户分享建议。感谢您的帮助。我正在尝试将代码应用到我的场景中，但它有更多的表，因此无法工作。还在这里尝试…谢谢！这很有帮助！