jdbc concepts in java jdbc programming- programming

jdbc concepts in java jdbc programming- programming

• 1.
  Java Database Connectivity (JDBC)
• 4.
  Components of JDBC
• 5.
  JDBC Architecture
• 7.
  Why use JDBC? •Before JDBC, ODBC API was used to connect and execute query to the database. But ODBC API uses ODBC driver that is written in C language which is platform dependent and unsecured. • That is why Sun Microsystem has defined its own API (JDBC API) that uses JDBC driver written in Java language.
• 8.
  What is API? •API (Application programming interface) is a document that contains description of all the features of a product or software. • It represents classes and interfaces that software programs can follow to communicate with each other. An API can be created for applications, libraries, operating systems, etc
• 9.
  Types of JDBCDriver • JDBC Driver is a software component that enables java application to interact with the database. There are 4 types of drivers
• 10.
  5 Steps toconnect to the database in java • There are 5 steps to connect any java application with the database in java using JDBC. They are as follows: 1. Register the driver class 2. Creating connection 3. Creating statement 4. Executing queries 5. Closing connection
• 11.
  1) Register thedriver class • The forName() method of Class class is used to register the driver class. This method is used to dynamically load the driver class. Syntax of forName() method public static void forName(String className) throws ClassNotFoundException Example to register the OracleDriver class Class.forName("oracle.jdbc.driver.OracleDriver");
• 12.
  2) Create theconnection object The getConnection() method of DriverManager class is used to establish connection with the database. Syntax of getConnection() method 1) public static Connection getConnection(String url)throws SQLExceptio n 2) public static Connection getConnection(String url,String name,String p assword) throws SQLException Example to establish connection with the Oracle database Connection con=DriverManager.getConnection( "jdbc:oracle: thin:@localhost:1521:xe","system","password");
• 13.
  3) Create theStatement object The createStatement() method of Connection interface is used to create statement. The object of statement is responsible to execute queries with the database. Syntax of createStatement() method • public Statement createStatement()throws SQLExce ption • Example to create the statement object • Statement stmt=con.createStatement();
• 14.
  4) Execute thequery The executeQuery() method of Statement interface is used to execute queries to the database. This method returns the object of ResultSet that can be used to get all the records of a table. Syntax of executeQuery() method public ResultSet executeQuery(String sql)throws SQLException Example to execute query ResultSet rs=stmt.executeQuery("select * from emp"); while(rs.next()) { System.out.println(rs.getInt(1)+" "+rs.getString(2)); }
• 15.
  5) Close theconnection object • By closing connection object statement and ResultSet will be closed automatically. • The close() method of Connection interface is used to close the connection. Syntax of close() method public void close()throws SQLException • Example to close connection con.close();
• 16.
  Example to connectto the Oracle database • For connecting java application with the oracle database, you need to follow 5 steps to perform database connectivity. • In this example we are using Oracle10g as the database. So we need to know following information for the oracle database: • Driver class: The driver class for the oracle database is oracle.jdbc.driver.OracleDriver. • Connection URL: The connection URL for the oracle10G database is jdbc:oracle:thin:@localhost:1521:xe where jdbc is the API, oracle is the database, thin is the driver, localhost is the server name on which oracle is running, we may also use IP address, 1521 is the port number and XE is the Oracle service name. You may get all these informations from the tnsnames.ora file. • Username: The default username for the oracle database is system. • Password: Password is given by the user at the time of installing the oracle database.
• 17.
  • Let's firstcreate a table in oracle database. • create table emp(id number(10),name varchar 2(40),age number(3));
• 18.
  Example to ConnectJava Application with Oracle database import java.sql.*; class OracleCon{ public static void main(String args[]){ try{ //step1 load the driver class Class.forName("oracle.jdbc.driver.OracleDriver"); //step2 create the connection object Connection con=DriverManager.getConnection( "jdbc:oracle:thin:@localhost:1521:xe","system","oracle"); //step3 create the statement object Statement stmt=con.createStatement(); //step4 execute query ResultSet rs=stmt.executeQuery("select * from emp"); while(rs.next()) System.out.println(rs.getInt(1)+" "+rs.getString(2)+" "+rs.getString(3)); //step5 close the connection object con.close(); }catch(Exception e){ System.out.println(e);} } }