You can use Excel's Import External Data feature to establish a connection to an external data source: Access, databases, OLAP databases, web pages, text file, sql server, or xml. This step is required prior to creating a report from one of these sources. The data from the external data source will be refreshed (reloaded) each time the report is generated.
Steps to create a connection:
On a blank worksheet, click on a cell where you want to load the data.
In Excel's menu, click Data | Import External Data | New Database Query
In the Choose Data Source box, define the database, query or OLAP cube that will be the source of the data. You can get help on creating a query by entering Import or Connect to Data in Excel's help search box.
The Query Wizard will appear once the data source has been defined. Use the wizard to select the data to return from the external data source.
Finally, in the Import Data window, choose the location of the data (Existing Worksheet or New Worksheet). This is the location where Excel will store the data.
Click the image below to view a video for creating a connection to an Oracle database.