What is OLE DB?

ODBC provides a standard interface for accessing relational databases, but Microsoft has develop their own OLE DB to support a wider range of data sources. OLE DB allows applications to access SQL databases as well as non-relational sources through a common programming model.

An OLE DB Provider exposes data to applications, while consumers such as ADO use the provider to retrieve and manipulate information. The data flow goes like this:

Application <> ADO <> OLE DB Provider <> SQL Server

SQL Server 7.0 includes the Microsoft OLE DB Provider for SQL Server. ADO applications typically select the provider in the connection string. An example connection string could be:

Provider=SQLOLEDB;Data Source=SERVER;Initial Catalog=Northwind;
Integrated Security=SSPI;

OLE DB supports transactions, rowsets, commands, and metadata while remaining independent of the underlying data source. Also worth noting is that OLE DB is part of Microsoft's Data Access Components (MDAC).

Hope this helps!