Microsoft Excel - Using External Data

Using External Data

Excel users can access external data sources via Microsoft Office features such as (for example) .odc connections built with the Office Data Connection file format. Excel files themselves may be updated using a Microsoft supplied ODBC driver.

Excel can accept data in real time through several programming interfaces, which allow it to communicate with many data sources such as Bloomberg and Reuters (through addins such as Power Plus Pro).

• DDE : "Dynamic Data Exchange" uses the message passing mechanism in Windows to allow data to flow between Excel and other applications. Although it is easy for users to create such links, programming such links reliably is so difficult that Microsoft, the creators of the system, officially refer to it as "the protocol from hell". In spite of its many issues DDE remains the most common way for data to reach traders in financial markets.

• Network DDE Extended the protocol to allow spreadsheets on different computers to exchange data. Given the view above, it is not surprising that in Vista, Microsoft no longer supports the facility.

• Real Time Data : RTD although in many ways technically superior to DDE, has been slow to gain acceptance, since it requires non-trivial programming skills, and when first released was neither adequately documented nor supported by the major data vendors.

Alternatively, Microsoft Query provides ODBC-based browsing within Microsoft Excel.