Create Logical Joins

Create Logical Joins

To create logical joins in the business model, perform the following steps:
1.Select the following tables in the Physical layer. Select only these tables:

2.Drag the selected tables from the Physical layer onto the SH business model folder in the Business Model and Mapping layer. This automatically creates logical tables in the Business Model and Mapping layer. Notice that each logical table has a yellow table icon. In the Business Model and Mapping layer, this indicates a fact table. Because you have not yet created the logical joins, all table icons are yellow. The icon color for dimension tables changes to white in a later step when you create logical joins.

3.Right-click the SH business model and select Business Model Diagram > Whole Diagram.

4.Rearrange the table icons so they are all visible. Place the Sales Facts table in the middle. Adjust the zoom factor, if desired.

5.Click the New Complex Join button in the toolbar.

6.Click the Channels table icon first and then click the Sales Facts table icon in the Logical Table Diagram window. The order is important. The second table clicked is the many side of the relationship. The Logical Join dialog box opens. Leave the default values as they are, but note which properties you can set: name, business model, tables, driving table, join type, and cardinality. Also note which properties you cannot set: the join expression and the join columns. Typically, when defining logical joins, you leave the defaults as they are.

7.Do not change the default values, click OK, and verify your work in the Logical Table Diagram. Notice that the fact table, Sales Facts, is at the many end of the join:

8.Repeat the steps for the remaining tables. Your final result should look similar to the picture.

9.Click the X in the upper right corner to close the Logical Table Diagram. Notice that the color of the table icons for the dimension tables has changed to white in the business model. In a business model, a yellow icon indicates a fact table and a white icon indicates a dimension table. Defining the join relationships determined which tables are the logical dimension tables and which is the logical fact table. A fact table is always on the many side of a logical join. You now have a logical star schema consisting of one logical fact table, Sales Facts, and five logical dimension tables: Channels, Customers, Products, Promotions, and Times.

10.Save the SH repository. Do not check global consistency.

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