关于JDBC

If you are using Java DB, it already comes with a JDBC driver. If you are using MySQL, install the latest version of Connector/J.

Contact the vendor of your database to obtain a JDBC driver for your DBMS.

There are many possible implementations of JDBC drivers. These implementations are categorized as follows:

Type 1: Drivers that implement the JDBC API as a mapping to another data access API, such as ODBC (Open Database Connectivity). Drivers of this type are generally dependent on a native library, which limits their portability. The JDBC-ODBC Bridge is an example of a Type 1 driver.

Note: The JDBC-ODBC Bridge should be considered a transitional solution. It is not supported by Oracle. Consider using this only if your DBMS does not offer a Java-only JDBC driver.

Type 2: Drivers that are written partly in the Java programming language and partly in native code. These drivers use a native client library specific to the data source to which they connect. Again, because of the native code, their portability is limited. Oracle‘s OCI (Oracle Call Interface) client-side driver is an example of a Type 2 driver.

Type 3: Drivers that use a pure Java client and communicate with a middleware server using a database-independent protocol. The middleware server then communicates the client‘s requests to the data source.

Type 4: Drivers that are pure Java and implement the network protocol for a specific data source. The client connects directly to the data source.

Check which driver types comes with your DBMS. Java DB comes with two Type 4 drivers, an Embedded driver and a Network Client Driver. MySQL Connector/J is a Type 4 driver.

Installing a JDBC driver generally consists of copying the driver to your computer, then adding the location of it to your class path. In addition, many JDBC drivers other than Type 4 drivers require you to install a client-side API. No other special configuration is usually needed.