JDBC - Connection class in java


In this tutorial we will learn What is Connection class in java JDBC.

  • Connection class is found in java.sql package in java JDBC.
  • java.sql.Connection helps in establishing connection/session with database in java JDBC.
  • java.sql.Connection extends java.lang.AutoCloseable interface from which java 7
  • Important methods of java.sql.Connection class in java JDBC >
    • Database information related methods of java.sql.Connection class in java JDBC >-
      • getMetaData - Method returns DatabaseMetaData. DatabaseMetaData can be used to obtain information about the database as a whole.
    • Transaction related methods of java.sql.Connection class in java JDBC >
      • setAutoCommit(boolean autoCommit) = for setting autocommit mode of transactions in java JDBC
      • commit() - method can be used to commit the transactions in java JDBC.
      • rollback() - method can be used to rollback the transactions in java JDBC.
      • close() - It closes the connection
    • Statement related methods of java.sql.Connection class in java JDBC >
      • createStatement()
      • prepareStatement(String sql)





Connection class - Example/ Full program to connect to Oracle database using Type 4 driver - java JDBC program >

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
/** Copyright (c), AnkitMittal JavaMadeSoEasy.com */
public class ConnectionClassExample {
   public static void main(String... arg) {
         
          Connection con =null;
          try {
                 // registering Oracle driver class
                 Class.forName("oracle.jdbc.driver.OracleDriver");
                 // getting connection
                 con = DriverManager.getConnection(
                              "jdbc:oracle:thin:@localhost:1521:orcl",
                              "ankit", "Oracle123");
                 // Test connection is null or not
                 if (con != null)
                       System.out.println("Connection established successfully!");
                 else
                       System.out.println("No Connection!");
          } catch (ClassNotFoundException e) {
                 e.printStackTrace();
          } catch (SQLException e) {
                 e.printStackTrace();
          }
          finally{
                 try {
                       if(con!=null) con.close(); // close connection
                 } catch (SQLException e) {
                       e.printStackTrace();
                 }
          }
   }
}
/*OUTPUT
Connection established successfully!
*/



Also read more program and example on how to create connection with following databases >

JDBC connection with Oracle 11g


JDBC connection with MySql database



JDBC connection with MsSql (Microsoft) database


JDBC connection with PostgreSQL database



So, In this tutorial we learned about what is java.sql.Connection class in java.

No comments:

Post a Comment