Data Access and Transactions
Data Access and Transactions |
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The ODBC standard is a widely recognized method of accessing data in a variety of relational databases. It is fast, lightweight, and provides a common method that is not optimized for any specific data source.
Like ODBC, OLE DB is an open specification. It was designed to build on the success of ODBC by providing another standard for accessing data. Whereas ODBC was created to access relational databases, OLE DB interfaces are designed to communicate with any data source including relational and nonrelational data, such as Microsoft® Excel spreadsheets, as well as e-mail, and text files. There is no restriction on the type of data you can access with OLE DB—relational databases, indexed sequential access method (ISAM), text, or hierarchical data sources.
OLE DB is set of programming interfaces designed for driver vendors who want to expose a data source, and for C++ developers wanting to develop custom data components. Microsoft® Visual Basic®, which does not support Automation objects, cannot use OLE DB directly.
Applications that use OLE DB fall into two categories: consumers and providers. A consumer application uses (or consumes) data through the OLE DB interfaces or components. A provider is any component or data source that allows consumers to access data in a uniform way through the OLE DB interfaces. In a sense, an OLE DB provider is similar to an ODBC driver that provides a uniform mechanism for accessing relational data.
Several OLE DB providers are available, including the Microsoft® ODBC provider, which exposes any ODBC-compliant database through OLE DB. Developers can implement an OLE DB provider for whatever data access they require, if one does not already exist.