Connecting the data

Tableau Prep supports lots of data sources and we can easily blend together multiple data sources, such as files and databases. Let's get started:

1. Navigate to File | New and create a new flow.
2. Click on the plus + sign near Connections and choose Microsoft Excel:
   

3. Choose the installs.xlsx file and click on Open. Connect the file and it will show us two available tables, Android and IOS, as shown in the following screenshot:
   

4. Using the drag-and-drop method, drag IOS to the canvas. Tableau Prep will create the Input step.

During the Input step, Tableau will read the file and learn about the structure of the file. For example, you can use the CSV or TSV file, and Tableau will automatically recognize the pattern and try to split into columns. We can also use the UNION operation by using the Wildcard union in order to read all the files and merge them into one. In addition, we can sample data in the case of a big dataset. Finally, we can apply filters.

5. Let's add one more dataset file with the Android installs. We have two ways of doing this: we can either drag and drop the Android sheet to the canvas or adjust the settings of IOS by enabling the Wildcard union.
6. We'll use the first method. Drag and drop Android to the canvas.