Oledb Introduction: Relationship between oledb and ODBC

Ole db (Oledb)It is Microsoft's strategic low-level application interface to different data sources. Ole db not only supports the Structured Query Language (SQL) of Open Database Connectivity (ODBC), but also supports other non-SQL data types.

As a design of Microsoft's Component Object Model (COM), ole db is a set of methods for reading and writing data (which may have been called a channel in the past ). Objects in old dB mainly include data source objects, stage objects, command objects, and row group objects. Applications using ole db use the following request sequence: initializing OLE to connect to the data source, issuing commands, processing results, releasing data source objects, and stopping OLE initialization

　　

Object Linking and Embedding,Object connection and embedding, OLE technology for short. Ole not only integrates desktop applications, but also defines and implements a mechanism that allows applications to be "connected" to each other as software "objects" (functions for integrating datasets and operating data, this connection mechanism and protocol are called the part object model.

　　

Ole is an object-oriented technology that allows you to develop reusable software components (COM ).

DB (Data Base) is a set of data that is organized and stored in the second-level memory according to a certain data model.

New concepts defined in the ole db Standard

Ole db divides traditional database systems into multiple logical components, which are relatively independent and communicate with each other. Each part of this component model is named differently:

　　

Data Provider ). Software components that provide data storage, ranging from common text files to complex databases on hosts or email storage, are examples of data providers. Some documents refer to developers of these software components as data providers.

　　

Data Service Provider ). Function components located on top of the data provider, separated from the past database management system, and run independently, such as query processor and cursor engine ), these components enable the data provided by the data provider to be displayed in the form of tabular data (no matter how physical data is organized and stored ), and Data Query and modification. The SQL Server 7.0 query handler is a typical example of this component.

　　

Business component ). Data service providers are used to process specific business information and functional components that can be reused. The middle layer (middle-tier) in the distributed database application system is a typical example of this component.

Data consumer ). In addition to typical database applications, any system program or application that needs to access data also includes development tools or languages that need to access various data sources.

　　

Relationship between ole db and ODBC

Since the ole db and ODBC standards are designed to provide a unified interface for accessing data, some people once wondered: Does ole db replace the New ODBC standard? The answer is no. In fact, ODBC standard objects are SQL-based data sources, while OLE DB objects are more extensive in any data storage. In this sense, ODBC-compliant data sources are a subset of ole db-compliant data storage. To comply with the ole db standard for ODBC-compliant data sources, you must also provide the corresponding Ole
The DB service provider is the same as the SQL Server ODBC driver to comply with ODBC standards. Now, Microsoft has provided a unified ole db service program for all ODBC data sources, called odbc ole db Provider.

　　

After the publication of odbc ole db provider, some people worry: Is ODBC provider a new layer on ODBC )? If yes, will access the ODBC data source using ole db affect performance? The answer is no. In fact, the role of ODBC provider is to replace ODBC driver manager, which serves as a bridge between applications and ODBC drivers and theoretically does not increase any overhead.