Question

我有以下要转换为视图的查询：

SELECT
  PartNum,
  SUM(IF(DAYOFWEEK(DeliveryDate) = '2', value, NULL)) AS 'Mon',
  SUM(IF(DAYOFWEEK(DeliveryDate) = '3', value, NULL)) AS 'Tue',
  SUM(IF(DAYOFWEEK(DeliveryDate) = '4', value, NULL)) AS 'Wed',
  SUM(IF(DAYOFWEEK(DeliveryDate) = '5', value, NULL)) AS 'Thu',
  SUM(IF(DAYOFWEEK(DeliveryDate) = '6', value, NULL)) AS 'Fri',
  SUM(IF(DAYOFWEEK(DeliveryDate) = '7', value, NULL)) AS 'Sat',
  SUM(IF(DAYOFWEEK(DeliveryDate) = '1', value, NULL)) AS 'Sun',
  SUM(IF(DeliveryDate > DATE_ADD(CURDATE(),INTERVAL 7 DAY), value, NULL)) AS 'Future'
FROM (
  SELECT PartNum, DeliveryDate , SUM(Ordered) value FROM v_archived_items_due
    GROUP BY PartNum, DeliveryDate
    ) t
  GROUP BY PartNum;

当我尝试将其保存为视图时，出现以下错误：

1349 - Views SELECT包含FROM子句中的子查询。

查询本身可以正常工作。如何将其变为视图？

Answer 1

MySQL不允许在视图中使用子查询，因此没有看到任何样本数据，看看如何在没有subqyery的情况下重新编写。由于这是按预期工作的，我将创建子查询的视图：

create view view1 as
    SELECT PartNum, DeliveryDate , SUM(Ordered) value 
    FROM v_archived_items_due
    GROUP BY PartNum, DeliveryDate;

然后在查询中调用此视图：

SELECT
  PartNum,
  SUM(IF(DAYOFWEEK(DeliveryDate) = '2', value, NULL)) AS 'Mon',
  SUM(IF(DAYOFWEEK(DeliveryDate) = '3', value, NULL)) AS 'Tue',
  SUM(IF(DAYOFWEEK(DeliveryDate) = '4', value, NULL)) AS 'Wed',
  SUM(IF(DAYOFWEEK(DeliveryDate) = '5', value, NULL)) AS 'Thu',
  SUM(IF(DAYOFWEEK(DeliveryDate) = '6', value, NULL)) AS 'Fri',
  SUM(IF(DAYOFWEEK(DeliveryDate) = '7', value, NULL)) AS 'Sat',
  SUM(IF(DAYOFWEEK(DeliveryDate) = '1', value, NULL)) AS 'Sun',
  SUM(IF(DeliveryDate > DATE_ADD(CURDATE(),INTERVAL 7 DAY), value, NULL)) AS 'Future'
FROM view1
GROUP BY PartNum;

Answer 2

行为设计

http://dev.mysql.com/doc/refman/5.1/en/create-view.html

您必须从子查询构建一个视图并使用它。

将交叉表查询转换为视图

2 个答案: