Open Database Connectivity (ODBC) is developed to share data between heterogeneous databases. It has become a main component of the Windows Open System Architecture (WOSA) and a standard for database access interfaces in Windows. ODBC provides a unified interface for accessing heterogeneous databases. It allows applications to access data managed by different database management systems (DBMSs) based on SQL. Therefore, applications can directly manipulate data in databases regardless of the database design. ODBC allows you to access database files on all types of computers, as well as non-database objects such as Excel files and ASCII data files.
OceanBase Connector/ODBC is developed based on the MySQL ODBC driver. This driver allows you to use the new data models provided by OceanBase Database, such as arrays. The following figure shows the architecture of OceanBase Connector/ODBC.
Application
An application accesses data on an OBServer node by using a standard ODBC API. Then the ODBC API communicates with the driver manager. To access data, the application only needs to know the data source name (DSN), without knowing where or how the data is stored or how the system is configured.
The following tasks are universal for any applications that use ODBC:
Select and connect to an OBServer node.
Submit SQL statements for execution.
Search for execution results, if any.
Handle errors.
Commit or roll back transactions that contain the SQL statements.
Disconnect from the OBServer node.
Most data access operations are performed through SQL statements. Therefore, applications that use OceanBase Connector/ODBC mainly need to submit SQL statements and search for execution results of the statements.
Driver manager
The driver manager is a library that manages communication between applications and drivers. It performs the following tasks:
Parses the DSN used to connect to the database. Database connection information is identified by the DSN. The DSN is a configuration string that identifies a database driver, a database, a database host, and optional identity authentication information. Any applications compatible with ODBC can use the same preconfigured DSN to connect to the data source.
Loads and unloads the driver required for accessing the database defined in the DSN. For example, after you configure a DSN for connecting to an OceanBase database, the driver manager loads OceanBase Connector/ODBC so that the ODBC API can communicate with OBServer nodes.
Handles ODBC function calls or passes them to drivers.
OceanBase Connector/ODBC
OceanBase Connector/ODBC is a library used to implement the functions supported by the ODBC API. It is used to handle ODBC function calls, submit SQL requests to OBServer nodes, and return results to applications. It allows you to modify the requests from applications to make them comply with the syntax specifications of OceanBase Database.
ODBC.INI
The ODBC.INI configuration file stores the driver and database information required for connecting to an OBServer node. Based on the DSN defined in the ODBC.INI configuration file, the driver manager can determine the driver to be loaded, and the driver can read connection parameters.
OBServer node
An OBServer node stores the information of OceanBase Database. Query operations can fetch data from the database, and insert and update operations can act on data in the database.