用于平均缺失日期的MySQL

Question

我期待通过平均距离该行之后最近的id和最近的id的日期来更新date列为NULL的行。

在下面的数据，这将更新ID 26行是2011-10-19

什么MySQL的声明将做到这一点？

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其他注意事项：

的数据看起来是这样的：

id  date   title 
-------------------------------------------- 
12  2011-09-01  Example One 
23  2011-10-02  Example Two 
26  NULL   Example Three 
27  2011-11-05  Example Four 
29  2012-01-05  Example Five 
37  NULL   Example Six 
38  2012-02-03  Example Seven 
-------------------------------------------- 

我宁愿不使用的过程。

到目前为止，我已经有了...

UPDATE `table` 
    SET `date`= 
     (AVG(
       (SELECT `date` FROM `table` WHERE `id`< ID_OF_PARENT_QUERY AND `date` IS NOT NULL LIMIT 1), 
       (SELECT `date` FROM `table` WHERE `id`> ID_OF_PARENT_QUERY AND `date` IS NOT NULL LIMIT 1) 
     )) 

    WHERE `date` IS NULL 

Answer 1

UPDATE tableX AS t 
    JOIN tableX AS next 
    ON next.id = 
     (SELECT MIN(n.id) 
     FROM tableX AS n 
     WHERE n.id > t.id 
      AND n.dateX IS NOT NULL 
     ) 
    JOIN tableX AS prev 
    ON prev.id = 
     (SELECT MAX(p.id) 
     FROM tableX AS p 
     WHERE p.id < t.id 
      AND p.dateX IS NOT NULL 
     ) 
SET t.dateX = prev.dateX + INTERVAL (DATEDIFF(next.dateX, prev.dateX)/2) DAY 
WHERE t.dateX IS NULL