Data Exchange

As the Windows operating system has progressed from Windows 3.0 to Windows XP and Vista, data transfer techniques have improved, from simple cut and paste using the Windows 3.0 clipboard, to Dynamic Data Exchange (DDE) and Open Database Connectivity (ODBC), to Automation (originally called Object Linking and Embedding [OLE], then OLE Automation) and Extensible Markup Language (XML).

In early Windows and Office versions, DDE and ODBC were difficult to use, cranky and unreliable in operation, and ODBC in particular often required elaborate setup. I know — I used both DDE and ODBC, when they were the only connectivity tools available. But I gladly dropped them when OLE became available in Windows 95/Office 95, because it offered a much simpler way to connect Office applications, though at first only in a limited manner.

Before Office 97, there was a distinction between Office components that were OLE servers, which could be manipulated by code running from other applications, and OLE clients, which could work with objects in OLE server applications' object models. Back in the days of Access 1.0 or even 2.0, Access developers had few tools available for connecting to other Office applications such as Word or Excel. Access, for example, was only a client, whereas Word was only a server.

In Office 95 AccessBasic was upgraded to standard Office VBA, and Access became an OLE server (previously it was only an OLE client). By Office 2000, all the major Office applications (Access, Word, Excel, Outlook, and PowerPoint) had been upgraded to support Automation both as clients and servers, so the OLE server/client distinction is no longer significant.

You can write Automation code in any major Office application to connect to any other Office application's data and functionality (and some third-party applications as well).

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