INFO: Visual Foxpro and ODBC Server-Side Cursors

Via ODBC, some applications make use of a technology called server-side cursors. Server-side cursors allow users to manipulate data on the server without bringing all of the information to the local workstation.

Visual FoxPro does not implement server-side cursors. If you need this functionality, technologies such as Remote Data Objects (RDO) that ship with Visual Basic might give you the desired behavior.

ODBC exposes several different cursor models that consist of different ways to manage the results of a query against a DataSource.

Visual FoxPro does not use any of the extended cursor models supported by ODBC, instead it uses one model where the local engine to manage results from the server. By doing this Visual FoxPro provides powerful features, including table buffering, creating indexes on results, and generally allowing the data from remote servers to behave similar to local data.

Another popular model is the server-side cursor model. Server-side cursors, instead of returning all of the results of a query to the client workstation, keep the data on the server and allow the user to look at only those records they are interested in.

Both models have benefits; however, Visual FoxPro implements only the first. To use server-side cursors from Visual FoxPro, you need to use an external tool for the client/server access. An example of one of these tools is the RDO component of Visual Basic 4.0.

RDO is an OLE Automation Server that provides client/server data access. You can call RDO from within Visual FoxPro just like any other automation server.

RDO is a component of Microsoft Visual Basic, and certain licensing restrictions regarding distribution of applications may apply. See your Visual Basic license agreement for details.

See the Visual FoxPro documentation for more information about "automation servers."