The External Data window appears automatically after you have successfully linked shapes in your Visio drawing to an external data source such as Excel spreadsheet, Access database, SQL Server database, SharePoint list, an OLEDB or ODBC data source, to name a few.
Hiding a column in the External Data window also hides the data in the linked shapes. For example, if you hide a Salary column, all mentions of Salary in shapes that are linked to the data are also hidden.
Note: To display the External Data window, on the Data tab, select the checkbox next to External Data Window.
Right-click any column heading in the External Data window, and then click Column Settings.
In the Column Settings dialog box, clear the check box of the column that you want to hide.
To show the column in the External Data window and in the linked shapes again, select the check box.
For more information about working with imported data, see Import data from Excel, SQL Server, SharePoint sites, and other external sources.