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select sum(c.cost)
from (select x.num as x, y.num as y, max(priority) as maxpriority
      from numbers x cross join
           numbers y join
           costs c
           on x.num between c.x and c.x + c.deltax and y.num between c.y and c.y + c.deltay
      where x.value between PIXELX and PIXELX and DELTAX and
            y.value between PIXELY and PIXELY and DELTAY
      group by x.num, y.num
    ) xyp join
    costs c
    on xyp.x between c.x and c.x + c.deltax and xyp.y between c.y + c.deltay and
        xyp.maxpriority = c.priority

在寻找由区域填充的数据库中的两点之间的“成本”时，我得到了这个答案，每个区域都有不同的成本。我一直试图让它与找出数据库模式一起工作，目前我正在#1054 - Unknown column 'x.value' in 'where clause'使用

Name    Type    Collation   Attributes  Null    Default Extra   Action
     1  num int(11)         No  None          Change      Drop    Browse distinct values     More

作为数字和

#   Name    Type    Collation   Attributes  Null    Default Extra   Action
 1  x   int(11)         No  None          Change      Drop    Browse distinct values     More
 2  y   int(11)         No  None          Change      Drop    Browse distinct values     More
 3  deltax  int(11)         No  None          Change      Drop    Browse distinct values     More
 4  deltay  int(11)         No  None          Change      Drop    Browse distinct values     More
 5  priority    int(11)         No  None          Change      Drop    Browse distinct values     More

作为成本。一直试图解决这个问题，非常感谢任何人的指点。

好的，它现在不会抛出错误，但它返回 null 而不是所选区域内的成本。

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1 回答 1

2

您的numbers表没有名为的列value，并且您尝试引用不存在的列，因此您收到错误。您当前的代码：

where x.value between PIXELX and PIXELX and DELTAX and

我猜你想num改用：

where x.num between PIXELX and PIXELX and DELTAX and
      y.num between PIXELY and PIXELY and DELTAY
于 2013-04-16T12:17:47.993 回答