What is JDBC?
JDBC is a set of Java API for executing SQL statements. This API consists of a set of classes and interfaces to enable programs to write pure Java Database applications.

What are drivers available?
a) JDBC-ODBC Bridge driver
b) Native API Partly-Java driver
c) JDBC-Net Pure Java driver
d)Native-Protocol Pure Java driver.

 What is the difference between JDBC and ODBC?
a) OBDC is for Microsoft and JDBC is for Java applications.
b) ODBC can’t be directly used with Java because it uses a C interface.
c) ODBC makes use of pointers which have been removed totally from Java.
d) ODBC mixes simple and advanced features together and has complex options for simple queries. But JDBC is designed to keep things simple while allowing advanced capabilities when required.
e) ODBC requires manual installation of the ODBC driver manager and driver on all client machines. JDBC drivers are written in Java and JDBC code is automatically installable, secure, and portable on all platforms.
f) JDBC API is a natural Java interface and is built on ODBC. JDBC retains some of the basic features of ODBC.

What are the types of JDBC Driver Models and explain them?
There are two types of JDBC Driver Models and they are:
a) Two tier model and b) Three tier model
Two tier model: In this model, Java applications interact directly with the database. A JDBC driver is required to communicate with the particular database management system that is being accessed. SQL statements are sent to the database and the results are given to user. This model is referred to as client/server configuration where user is the client and the machine that has the database is called as the server.

Three tier model: A middle tier is introduced in this model.
The functions of this model are:
a) Collection of SQL statements from the client and handing it over to the database,
b) Receiving results from database to the client and
c) Maintaining control over accessing and updating of the above.

What are the steps involved for making a connection with a database or how do you connect to a database?
a) Loading the driver : To load the driver, Class. forName() method is used. Class. forName("sun. jdbc. odbc. JdbcOdbcDriver"); When the driver is loaded, it registers itself with the java. sql. DriverManager class as an available database driver.
b) Making a connection with database: To open a connection to a given database, DriverManager. getConnection() method is used. Connection con = DriverManager. getConnection ("jdbc:odbc:somedb", “user", “password");
c) Executing SQL statements : To execute a SQL query, java. sql. statements class is used. createStatement() method of Connection to obtain a new Statement object. Statement stmt = con. createStatement(); A query that returns data can be executed using the executeQuery() method of Statement. This method executes the statement and returns a java. sql. ResultSet that encapsulates the retrieved data: ResultSet rs = stmt. executeQuery("SELECT * FROM some table");
d) Process the results : ResultSet returns one row at a time. Next() method of ResultSet object can be called to move to the next row. The getString() and getObject() methods are used for retrieving column values: while(rs. next()) { String event = rs. getString("event"); Object count = (Integer) rs. getObject("count");

What type of driver did you use in project?
You may answer like : JDBC-ODBC Bridge driver ( because it is a driver that uses native(C language) libraries and makes calls to an existing ODBC driver to access a database engine).

What are the types of statements in JDBC?
Statement: to be used createStatement() method for executing single SQL statement
PreparedStatement — To be used preparedStatement() method for executing same SQL statement over and over.
CallableStatement — To be used prepareCall() method for multiple SQL statements over and over.

No comments:

Post a Comment

Related Posts Plugin for WordPress, Blogger...