jdbc tutorial for m.sc(it)

8/7/2019 JDBC Tutorial for M.Sc(IT)

1/22

JDBC Tutorial

M.Sc (IT) Sem-IV

Prepared By Prof. Rakhi Budhrani


2/22

What is JDBC

The JDBC API is a Java API that can access any

kind of tabular data, especially data stored in

a Relational Database.

JDBC stands for Java Database Connectivity.

JDBC works with Java on a variety of

platforms, such as Windows, Mac OS, and the

various versions of UNIX.



3/22


4/22

Common JDBC Components

The JDBC API provides the following interfaces and classes:

DriverManager: This interface manages a list of database drivers. Matchesconnection requests from the java application with the proper database

driver using communication subprotocol.

Driver: This interface handles the communications with the database

server. You will interact directly with Driver objects very rarely. Instead,

you use DriverManager objects, which manages objects of this type.

Connection : The connection object represents communication context,

i.e., all communication with database is through connection object only.

Statement : You use objects created from this interface to submit the SQL

statements to the database.

ResultSet: These objects hold data retrieved from a database after you

execute an SQL query using Statement objects.

SQLException: This class handles any errors that occur in a database

application.



5/22

The JDBC 4.0 Packages

The java.sql and javax.sql are

the primary packages for JDBC

4.0. It offers the main classes

for interacting with your data

sources.

JDBC Driver

JDBC drivers enable you toopen database connections

and to interact with it by

sending SQL or database

commands then receiving

results with Java.



6/22

JDBC Drivers Types:

Type 1: JDBC-ODBC Bridge

Driver:

In a Type 1 driver, a JDBC

bridge is used to accessODBC drivers installed oneach client machine. UsingODBC requires configuringon your system a Data

Source Name (DSN) thatrepresents the targetdatabase.



7/22

Type 2: JDBC-Native API:

In a Type 2 driver, JDBC APIcalls are converted intonative C/C++ API calls whichare unique to the database.

These drivers typicallyprovided by the databasevendors and used in thesame manner as the JDBC-

ODBC Bridge, the vendor-specific driver must beinstalled on each clientmachine.



8/22


9/22

Type 100: 100% pure Java:

In a Type 4 driver, a pure

Java-based driver that

communicates directly with

vendor's database throughsocket connection. This is

the highest performance

driver available for the

database and is usually

provided by the vendor

itself.



10/22

Which Driver Should I use?

If you are accessing one type of database, such asOracle, Sybase, or IBM, the preferred driver type is 4.

If your Java application is accessing multiple types of

databases at the same time, type 3 is the preferreddriver.

Type 2 drivers are useful in situations where a type 3 ortype 4 driver is not available yet for your database.

The type 1 driver is not considered a deployment-leveldriver and is typically used for development and testingpurposes only.



11/22

Steps for JDBC Connection

After you've installed the appropriate driver, it's time to establish adatabase connection using JDBC.

The programming involved to establish a JDBC connection is fairlysimple. Here are these simple four steps:

Import JDBC Packages: Add import statements to your Java

program to import required classes in your Java code.

Register JDBC Driver: This step causes the JVM to load the desired

driver implementation into memory so it can fulfill your JDBC

requests.

Database URL Formulation: This is to create a properly formatted

address that points to the database to which you wish to connect. Create Connection Object: Finally, code a call to the DriverManager

object's getConnection( ) method to establish actual database

connection.



12/22

Import JDBC Packages:

The Import statements tell the Java compiler

where to find the classes you reference in your

code and are placed at the very beginning of your

source code.

To use the standard JDBC package, which allows

you to select, insert, update, and delete data in

SQL tables, add the following imports to yoursource code:

import java.sql.* ; // for standard JDBC programs



13/22

Register JDBC Driver:

You must register the your driver in your program before you use it.

Registering the driver is the process by which the Oracle driver'sclass file is loaded into memory so it can be utilized as animplementation of the JDBC interfaces.

You need to do this registration only once in your program.

to register a driver use Java's Class.forName() method to

dynamically load the driver's class file into memory, whichautomatically registers it.


try {

Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");

} catch(java.lang.ClassNotFoundException e) {

System.err.print("ClassNotFoundException: ");

System.err.println(e.getMessage());

}


14/22

Database URL Formulation:

After you've loaded the driver, you can establish a connection using the

DriverManager.getConnection() method.getConnection(String url, String user, String password)

Here each form requires a database URL. A database URL is an address

that points to your database.


static String userid="scott",password = "tiger";

static String url = "jdbc:odbc:Rakhi";

Here Rakhi is the DNS which you have created in the control pannel with the help

of ODBC

con = DriverManager.getConnection(url, userid, password);

Create Connection Object:

Using a database URL with a username and password:DriverManager.getConnection() method is used to create a connection object.

The most commonly used form of getConnection() requires you to pass a database

URL, a username, and a password:


15/22

JDBC - Statements

Once a connection is obtained we can interact with the database. The

JDBC Statement, CallableStatement, and PreparedStatement interfacesdefine the methods and properties that enable you to send SQL or PL/SQL

commands and receive data from your database.


nterfaces Recommended Use

Statement

Use for general-purpose access to your database. Useful

when you are using static SQL statements at runtime.

The Statement interface cannot accept parameters.

PreparedStatement

Use when you plan to use the SQL statements many

times. The PreparedStatement interface accepts input

parameters at runtime.

CallableStatement

Use when you want to access database stored

procedures. The CallableStatement interface can also

accept runtime input parameters.


16/22

Creating Statement Object:

Statement stmt = null;

try {

stmt =conn.createStatement( );

. . .

} catch (SQLException e) {

. . .

} finally {

. . .

}


Statement stmt = cn.createStatement();

stmt.executeUpdate(insertString1);




insertString1 = "insert into Master

values(100,'SAL',30.5,'1-Dec-09',40.5)";


17/22



18/22



19/22

JDBC - Result Sets

The SQL statements that read data from a databasequery return the data in a result set. The SELECTstatement is the standard way to select rows from adatabase and view them in a result set. Thejava.sql.ResultSetinterface represents the result set ofa database query.

The methods of the ResultSet interface can be brokendown into three categories:

Navigational methods: used to move the cursoraround.

Get methods: used to view the data in the columns of

the current row being pointed to by the cursor. Update methods: used to update the data in the

columns of the current row. The updates can then beupdated in the underlying database as well.



20/22

Select Query

Statement st=cn.createStatement();

ResultSet rs=st.executeQuery("Select * fromMaster");

while(rs.next()){

System.out.println(rs.getInt(1) + "\t" +

rs.getString(2)+ "\t\t" +rs.getF

loat(3)+"\t"+rs.getDate(4)+"\t"+rs.getFloat(5));

}



21/22



22/22

Closing

At the end of your JDBC program, it is requiredexplicitly close all the connections, statements,recordsets to the database to end each database

session. rs.close();

st.close();

cn.close();

For more details visit:http://www.tutorialspoint.com/jdbc/index.htm


jdbc tutorial for m.sc(it)

Documents