10+ steps to using Excel 's new data modeling feature - TechRepublic
I want to link this "linked Excel Worksheet" by Member Number (this is the *one* connection) I want to create a one-to-many relationship from. Have you had a look at pivot tables? This would appear to do exactly as you want . The first thing to do is to ensure that you have a header row. By building a relationship between sheets, Excel makes Currently, the PivotTable frame evaluates only one table, DailyTotalsTable.
Try following these steps to get the answers you need. Determine which tables to specify in the relationship If your model contains just a few tables, it might be immediately obvious which ones you need to use. But for larger models, you could probably use some help. One approach is to use Diagram View in the Power Pivot add-in. Diagram View provides a visual representation of all the tables in the Data Model.
Using Diagram View, you can quickly determine which tables are separate from the rest of the model.
If you follow the chain of table relationships that connect to the tables you want to use, you will probably discover that you have two or more one-to-many table relationships. There is no easy workaround that works for every situation, but you might try creating calculated columns to consolidate the columns you want to use into one table. For example, suppose you have a model that contains product sales by territory, and that you subsequently import demographic data to find out if there is correlation between sales and demographic trends in each territory.
Because the demographic data comes from a different data source, its tables are initially isolated from the rest of the model. For example if the demographic data is organized by region, and your sales data specifies which region the sale occurred, you could relate the two datasets by finding a common column, such as a State, Zip code, or Region, to provide the lookup. Besides matching values, there are a few additional requirements for creating a relationship: Data values in the lookup column must be unique.
In a Data Model, nulls and empty strings are equivalent to a blank, which is a distinct data value.
Data types of both the source column and lookup column must be compatible. For more information about data types, see Data types in Data Models. We have a separate table which lists the states and territories and their respective regions — see Figure 1. They have been named tblSales and tblStates respectively. I highly recommend using the Format as Table feature as it tells Excel to treat the table as a database table.
The companion video includes more details about Format As Table. Figure 2 This opens the Manage Relationships dialog, see Figure 3. The bottom dialog in Figure 4 has the selections necessary to create the relationship between the two tables.
Figure 4 The dropdowns on the left allow you to select a table name. The dropdowns on the right list all the column names in the table selected. You need to select the shared column in both tables. This example shows that the names of the columns can be different.
This is a simple example and in practice you may need to create multiple relationships between multiple tables to get to the data you need. Relationships between tables can be complex.
Relationships between tables in a Data Model
Once created, the relationship will be listed in the Manage Relationship dialog, see Figure 5. You can do this before you import the data, or by creating a calculated column in the Data Model using the Power Pivot add-in.
However, you can use DAX functions to model many-to-many relationships. A self-join is a recursive relationship between a table and itself.
Self-joins are often used to define parent-child hierarchies. In other words, the following set of relationships is prohibited. Automatic detection and inference of relationships in Power Pivot One of the advantages to importing data using the Power Pivot add-in is that Power Pivot can sometimes detect relationships and create new relationships in the Data Model it creates in Excel.
Easy steps to make data Relationships work in Excel
When you import multiple tables, Power Pivot automatically detects any existing relationships among the tables. The detection algorithm uses statistical data about the values and metadata of columns to make inferences about the probability of relationships. Data types in all related columns should be compatible. For automatic detection, only whole number and text data types are supported.
Easy steps to make data Relationships work in Excel | INTHEBLACK
For the relationship to be successfully detected, the number of unique keys in the lookup column must be greater than the values in the table on the many side. In other words, the key column on the many side of the relationship must not contain any values that are not in the key column of the lookup table.
For example, suppose you have a table that lists products with their IDs the lookup table and a sales table that lists sales for each product the many side of the relationship. To have Excel detect the relationship, you need to first update the Product lookup table with the IDs of the missing products. Make sure the name of the key column on the many side is similar to the name of the key column in the lookup table.
The names do not need to be exactly the same.