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By far, the most popular data access mechanism among experienced, heavyweight Visual Basic developers is RDO (Remote Data Objects). Like ADO and DAO, RDO is object-based, providing a relatively tight, lightweight interface to ODBC. Unlike its underlying ODBC API calls, RDO is very user-friendly, making developing serious database-oriented applications fast and relatively easy. |
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If you've worked with DAO, working with RDO won't be much more complex, even though it offers more powerful, faster features. The underlying mechanisms of the complex ODBC architecture are controllable through RDO. |
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RDO, and its DAO Data control alternativethe Remote Data control, lets your applications access ODBC data sources without using a local query processor. Without localizing a query processor, your applications enjoy higher performance and more flexibility when accessing remote database engines. Other key features of RDO include |
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Executing action queries (INSERT, UPDATE, or DELETE queries, to name more notable ones) that implement data manipulation or data definition operations |
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Creating resultsets (or recordsets) with or without cursors of varying complexities |
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Enabling synchronous, asynchronous, or event-driven asynchronous processing (the latter two features ensure your application isn't blocked while the server is processing lengthy queries, among other reasons) |
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Executing stored procedures that return resultsets (or recordsets) with or without output parameters and return values |
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Enabling you to limit the number of rows returned or processed |
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Running general queries and processing any number of resultsets |
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There are only a few, minor drawbacks to RDO, compared with DAO, RDO isn't as effective as Jet-based DAO in accessing Jet or ISAM databases. Also, RDO can access relational databases only through existing ODBC drivers. Of course, these drawbacks are more than outweighed by the fact that you can access databases more powerful than Access, including SQL Server, Oracle, DB2, Sybase, Informix, and other ODBC-compliant, relational DBMS customers. In addition, RDO provides the objects, properties, and methods you need in order to implement code to handle more sophisticated aspects of stored procedures and complex resultsets. |
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The Remote Data Objects in common or similar to counterparts in ADO and RDO include |
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RDO.rdoConnection
RDO.rdoConnections
RDO.rdoError
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