Information Technology Reference
In-Depth Information
compliant, the developer can use the same code to access different SQL data-
bases. There are two main varieties of data integration technologies using
CLI concept. The first variety is the one championed by Microsoft called
the Open Database Connectivity (ODBC) standard and other standards like
Object Link and Embedding database (OLE DB). The other variety is the
JDBC standard from Javasoft.
5.2.1 Microsoft Open Database Connectivity (ODBC)
ODBC is a CLI and has a set of standard function calls to a database. Using
ODBC, an application can remotely access a database—developers do not care
what database or platform is used to store application data. The same code for
data access can work for any database that has an ODBC driver, as long as
the right ODBC Driver Manager exists for that platform. This eases the task
of data access. Initially, ODBC has encountered database performance issues.
However, it has evolved into a high-performance database access mechanism.
In order for ODBC to work, an operating system-specific driver manager
needs to be utilized. A driver manager dynamically determines which ODBC
driver to use for a program to access a database that is ODBC compliant. The
ODBC driver takes the request from the calling program and translates it to
a native format that the database can understand, and the database performs
the request. Microsoft provides the ODBC Driver Manager for its operating
systems; there are other ODBC Driver Managers for other operating sys-
tems from other vendors. As long as an ODBC driver exists for a database,
an application can ask the database to perform a request that is supported
natively in the database. Therefore, if a function supported by ODBC does
not exist in the database, the ODBC driver for that database cannot support
that function. Conversely, if a database has a function that is not supported
in the ODBC standard, then the ODBC driver cannot support that function.
5.2.2 Java Database Connectivity (JDBC)
Like ODBC, JDBC is a CLI and it has its own set of functions. It enables a Java
program to access a database with a JDBC driver. The architecture of JDBC is
similar to ODBC. There is the JDBC Driver Manager, which is supplied in the
Java Development Toolkit. When using the JDBC Driver Manager, the devel-
oper has to register the driver with the Driver Manager in the Java program.
There are four types of JDBC drivers:
• Type 1 is the JDBC-ODBC bridge driver.
• Type 2 is native application programming interfaces (APIs) partly
Java-technology-enabled driver.
• Type 3 is the net-protocol fully Java-technology-enabled driver.
• Type 4 is the native-protocol fully Java-technology-enabled driver.
Search WWH ::
Custom Search