DATABASE CONNECTIVITY USING MICROSOFT ODBC

Ø ODBC architecture consist of four components:

·        Application Programming Interface: Calls ODBC functions to connect to a data source, send and receive data, and disconnect.

·        Driver Manager: Provides information to an application, loads driver dynamically as they are needed.

·        Driver: Processes ODBC function calls and manages all exchanges between an application and a specific relational database.

·        Data source: Comprises the data and its associated database engine.

Ø

APPLICATION

ODBC API

ODBC DRIVER MANAGER

ODBC DRIVER

ODBC DRIVER

ODBC DRIVER

DATA SOURCE

DATA SOURCE

DATA SOURCE

Calls ODBC API functions to submit SQL statements and retrieve results.

Load the ODBC drivers for applications, passes request to the driver and result to the application. etrieve results.

Processes ODBC function calls, submits SQL requests to a specific data source, and to end application.

Processes requests from driver and returns results to driver.

An application uses the ODBC API to connect to a data source, submit SQL statements, fetch data and disconnect.

Ø An application uses the following function calls and processes to access a data using ODBC API:

·        Allocate Environment Handler:

·        Allocate Connection:

·        Connect:

·        Allocate Statement:

·        Execute SQL statement:

·        Fetch Result Set:

·        Free Statement:

·        Disconnect:

·        Free Connection:

·        Free Environment Handle: