Setting up Multiple Data Connections

Every Tableau workbook can contain multiple data connections, worksheets, views, and dashboards.

The basic unit is the data connection.

Each worksheet has one view and one data connection. Worksheets can share the same data connection.

A dashboard can contain any number of views, regardless of which data connection is used by the view.

If you modify a data connection, any worksheet or view that connects to this data connection changes to reflect the modification.

Create a new data connection when you need to change the data without affecting the current worksheets. You can connect to a new data source, connect to a new table in the same data source, add tables, remove tables, change the fields used, or re-write custom SQL.

There are two methods to create an additional data connection. The first is to add a new data connection. The second is to duplicate and modify an existing data connection.

Add a connection to a new data source.

Scenario:

• The existing data connection is to file-based data, such as Excel.
• You need a connection to a second data source, such as Oracle.

In this scenario, the best route is to create a new data connection from scratch.

Step 1

In the same workbook, select Data > Connect to Data.

Step 2

In the Connect to Data dialog box, select the type of connection. In this example, select Oracle, and then click Next.

Step 3

In the Connection dialog box, provide the required information. The types of information required are determined by the type of connection requested.

When you complete the data connection, you can select it from the connection list in the Data window.

Duplicate, then modify, an existing data connection.

Scenario:

• You have a data connection to the 2009 Sales table.
• You need a data connection to the 2010 Sales table.

In this scenario, the best route is to duplicate the current data connection to the 2009 Sales table, then modify the duplicate connection to point to the 2010 Sales table.

Step 1

In the data connection list in the Data window, select the data connection you want to duplicate.

Step 2

Select Data > Data Connection > Duplicate.

Step 3

To change the data connection from the 2009 Sales table to the 2010 Sales table, select Data > Data Connection > Edit; in the dialog box, select the 2010 Sales table.

Step 4

In the Data window connection list, select the copy of the connection.

Step 5

Select Data > Data Connection > Rename.

Step 6

In the Rename Connection dialog box, in the Name text box, type a name for the duplicate connection.

Step 7

Click OK.

Use the connection list in the Data window to switch between the 2009 Sales and the 2010 Sales connections when creating new worksheets.

Restrictions

Data connections cannot be changed or modified without affecting all other worksheets using the same data connection.

Once a worksheet has data on the view, you cannot change the data connection used to a different data connection.