使用 Dim tables 在 Fact table 上创建数据仓库

Data warehouse creation on Fact table with Dim tables

我正在尝试理解暗淡的 table 与事实 table 的关联逻辑。

我目前有一个事实 table 没有数据,并且有两个 Dim Table 有数据。

昏暗Table 1:郊区

昏暗 Table 2:餐厅

因为 Dim table 有不同的行数。如何使 Fact table link 与显示正确 order/results 的郊区和餐馆的 Dim table 相匹配?

  • 事实 table 持有事实或数字。
  • 维度 table 是关于事实的维度或方面。

The data stored in fact, determines the granularity of the facts. The granularity of facts decide the granularity of dimension tables.

E.g., Suburbs is a dimension : Holds the suburb details
Restaurants is a dimension : Holds the Restaurant details
FactRestaurantSales is a Fact : Holds the sales at Restaurant granularity level.

1 份$20 美元的披萨在 Bellevue 郊区的一家餐厅 Pizza Garden 售出,将存储如下:

昏暗郊区:

+-------------+------------+
| DimsuburbId | Suburbname |
+-------------+------------+
|          1  | Bellevue   |
+-------------+------------+

昏暗餐厅:


+-----------------+----------------+
| DimRestaurantId | RestaurantName |
+-----------------+----------------+
|              1  | Pizza Garden   |
+-----------------+----------------+

DimItem;


+-----------+----------+
| DimItemId | ItemName |
+-----------+----------+
|        1  | Pizza    |
+-----------+----------+

事实餐厅销售:


+-----------------------+--------------+-----------------+---------+-------------+----------------+
| FactRestaurantSalesId |  DimSuburbId | DimRestaurantId | DimItem | DollarSales | QuantitySales  |
+-----------------------+--------------+-----------------+---------+-------------+----------------+
|                   1   |          1   |              1  |      1  |          20 |            1   |
+-----------------------+--------------+-----------------+---------+-------------+----------------+