Question

如何计算每栋建筑的房间面积百分比？我有2张桌子：建筑物和房间。客房表中的每间客房均为面积，面积为平方米：

Rooms Table
Room    Area  Building FKey
Room1   10    BK
Room2   20    CK

Building Table
PKey Name
BK  Building1
CK  Building2


Result
Building  area (%)
Building 1  10%
Building 2  30%

Answer 1

我是否理解你想要每个房间的百分比到建筑物？或者您想看到每栋建筑的房间总数吗？

如果是后者，则需要绑定总建筑面积。

如果是前者，这样的事情应该有效...你基本上需要计算每个建筑物的总面积，然后将房间面积除以。

SELECT Building.Name, 
       Rooms.Name,
    100.0 * Area / (SELECT SUM(R2.Area) FROM Rooms R2 WHERE R2.BuildingID = Rooms.BuildingID) AS Percentage
FROM Rooms
    INNER JOIN Building     
        ON Rooms.BuildingID = Building.BuildingID

如果是后者，那么这样的事情（即使你没有指定存储总建筑面积的地方......假设在建筑物表上）：

SELECT BuildingID, SUM(Rooms.Area) / Building.Area * 100.0
FROM Rooms
    INNER JOIN Building     
        ON Rooms.BuildingID = Building.BuildingID
GROUP BY Building.BuildingID

Answer 2

假设我终于明白了你想要计算的百分比（每个建筑物的总面积/所有建筑物的总面积），你可以尝试这样的事情：

SELECT Building.Name, 
       100.0 * Sum(Room.Area) / (SELECT SUM(R2.Area) FROM Rooms R2) 
       AS Percentage
FROM Rooms INNER JOIN Building     
     ON Rooms.BuildingID = Building.BuildingID
GROUP BY Building.Name

SQL根据不同表中的2列计算百分比

2 个答案: