What is OLE DB? #
OLE DB stands for Object Linking and Embedding Database. It is a Microsoft technology that provides a standardised way to represent and work with data from different sources, enabling applications to access and manipulate data in a consistent and efficient manner.
OLE DB is a Windows-only database API for accessing data in a variety of file formats including any SQL-based data sources and relational databases (MySQL, MS-SQL, Oracle etc.), as well as non-SQL-based data sources, such as directory services, XML spreadsheets, emails on MS Exchange Server etc.
The API provides a set of interfaces implemented using component-based data access technology, Component Object Model (COM), which allows applications to access data from these sources.
Microsoft initially developed OLE DB as a successor to the Open Database Connectivity (ODBC) standard, extending its feature set to support a wider variety of non-relational databases, such as object databases and spreadsheets.
OLE DB is often used in combination with other Microsoft technologies, such as ActiveX Data Objects (ADO) and Microsoft SQL Server, to provide a comprehensive data access solution for Windows-based applications.
How does OLE DB work? #
OLE DB allows applications to access data regardless of the specific format or location of the data. This means that applications can be designed to work with multiple data sources without requiring significant changes to the code.
OLE DB uses a common data format for all data sources it supports, which is based on a set of standard data types, such as integer, floating-point, date/time, string and binary data types.
The OLE DB format also includes metadata information that describes the structure of the data source. For example, the metadata might include the names and data types of tables, columns and indexes in a relational database.
Additionally, OLE DB supports a range of features, including transaction management, data integrity and security, which help ensure the reliability and consistency of the data being accessed.
OLE DB providers, which can be developed by Microsoft or third-party vendors, are responsible for converting the native data format of a data source into the OLE DB format. This involves mapping the data types and structure of the source data to the standard OLE DB format. Once the data is in the OLE DB format, it can be accessed and manipulated by any OLE DB consumer application that supports the format.
- An application initiates a request to access data by calling an OLE DB consumer interface.
- The OLE DB provider interface receives the request and determines the appropriate data source to use.
- The provider establishes a connection to the data source and sends the request.
- The data source retrieves the requested data and returns it to the provider.
- The provider formats the data into a standard OLE DB format and returns it to the consumer interface.
- The application can then manipulate the data as needed.
For more information on OLE DB and how to use the Database Query (OLEDB) tool, download the whitepaper below.
