Part V: Understanding Power Pivot and Power Query
FIGURE 35.9
When you create relationships, the Power Pivot diagram will show join lines between your
tables.
The joins in Power Pivot are one-to-many joins. This means that when a table is joined to
another, one of the tables has unique records with unique index numbers, while the other
can have many records where index numbers are duplicated.
Notice that the join lines have arrows pointing from a table to another table. The arrows in
these join lines will always point to the table that has the nonduplicated unique index.
In this case, the Customers table contains a unique list of customers, each having its own
unique identifier. No CustomerID in that table is duplicated. The Invoice header table has
many rows for each CustomerID; each customer can have many invoices.
To close the diagram and get back to seeing the data tables, click the Data View command in the Power Pivot window.
Managing existing relationships
If you need to go back and edit or delete a relationship between two tables in your data
model, you can do so by following these steps:
- Activate the Power Pivot window, select the Design tab, and then click the
Manage Relationships command.
- In the Manage Relationships dialog box shown in Figure 35.10, click the rela-
tionship with which you want to work and select Edit or Delete.
