Question

我有一个Visitdate列，其中包含一年中常去的患者。我必须估算访问日期和后续日期，如下所示。

Table aaa

    ID    VDate                   Visit
    10003 2003-09-26 00:00:00.000 1
    10003 2004-05-15 00:00:00.000 2
    10003 2007-01-09 00:00:00.000 3
    10003 2007-07-05 00:00:00.000 4

我希望我的结果是

+-------+------------+------------+
| id    | visit_date | follow_up  |
+-------+------------+------------+
| 10003 | 2003-09-26 | 2004-05-15 |
| 10003 | 2004-05-15 | 2007-01-09 |
| 10003 | 2007-01-09 | 2007-07-05 |
| 10003 | 2007-07-05 | Null       |
+-------+------------+------------+

Answer 1

如果使用支持窗口功能的MySQL 8：

SELECT ID
     , VDate AS visit_date
     , lead(VDate, 1) OVER (PARTITION BY ID ORDER BY Visit) AS follow_up
FROM aaa
ORDER BY ID, Visit;

应该可以解决问题。

如果使用MySQL 5，也许类似

SELECT ID
     , VDate AS visit_date
     , (SELECT VDate FROM aaa AS a2 WHERE a.ID = a2.ID and a.Visit + 1 = a2.Visit) AS follow_up
FROM aaa AS a
ORDER BY ID, Visit;

格式化日期留给读者练习。

Answer 2

如果您已经有了该值，并且知道要更新的行的id，则应该为您设置该值：

UPDATE aaa SET follow_up = '2007-07-05' WHERE id = 10004;

请注意，在您的示例中，所有行都具有相同的ID。应该有一些唯一的ID或，并且可以在where子句中添加以检查您要查找的原始日期。

Answer 3

DECLARE @Table TABLE (ID INT, VDate DATETIME, VISIT INT)
INSERT INTO @Table
    VALUES (10003, '2003-09-26 00:00:00.000', 1), (10003, '2004-05-15 00:00:00.000', 2), (10003, '2007-01-09 00:00:00.000', 3), (10003, '2007-07-05 00:00:00.000', 4)


  SELECT
        T1.ID
       ,CAST(T1.VDate AS DATE) AS visit_date
       ,(SELECT TOP 1
                CAST(T2.VDate AS DATE)
            FROM @Table AS T2
            WHERE T1.ID = T2.ID
            AND T2.VDate > T1.VDate)
        AS follow_up
    FROM @Table AS T1
    ORDER BY VISIT

Demo

如果您想更新列

DECLARE @Table TABLE (ID INT, VDate DATETIME, follow_up DATETIME, VISIT INT)
INSERT INTO @Table (ID, VDate, VISIT)
    VALUES (10003, '2003-09-26 00:00:00.000', 1), (10003, '2004-05-15 00:00:00.000', 2), (10003, '2007-01-09 00:00:00.000', 3), (10003, '2007-07-05 00:00:00.000', 4)

UPDATE T1
SET T1.follow_up = (SELECT TOP 1
        T2.VDate
    FROM @Table T2
    WHERE T1.ID = T2.ID
    AND T2.VDate > T1.VDate)
FROM @TABLE T1

SELECT
    ID
   ,CAST(VDate AS DATE) AS visit_date
   ,CAST(follow_up AS DATE) AS follow_up
FROM @Table

UpdateDemo

如何更新特定栏中的下一个日期

3 个答案: