Open Database Connectivity (ODBC): ODBC is a C language callable API suite which was developed by Microsoft. For different DBMS brands it uses a database interface module called driver. For an application program to access a database, a API call is made by the application program. Then driver manager routes it to a particular driver. After that the application program can communicate with different databases ODBC has features such as connection browsing for simplifying data source connection process and connection pooling for improving efficiency of ODBC connections.
Architecture of ODBC: Architecture of ODBC contains the following components:
1) ODBC callable API: It is used by application programs for making function calls.
2) ODBC drivers: For each DBMS brand there is a separate driver. A driver is used for translating standard ODBC calls to a specific DBMS call. To increase efficiency two or more SQL statements are passed as a statement batch.
3) Driver manager: It is used for managing the different ODBC drivers. It also routes API calls made by application programs to specific drivers.
Call level interface (CLI): ODBC was later used by SQL Access Group for using it as a standard for providing vendor independent database access. Nowadays, almost all databases based on SQL have a ODBC/CLI interface.