Java Database Connectivity (JDBC)

What is Java Database Connectivity (JDBC)?

Java Database Connectivity (JDBC) is a Java-based data access technology that enables Java applications to connect to relational databases. It consists of a set of classes and interfaces that provide a standard API for establishing a connection to a database and executing SQL statements.

JDBC provides a standardized API for interacting with a database, regardless of the database vendor or type. This means that the same JDBC code can be used to connect to different databases, as long as there is a JDBC driver available for that database.

To use JDBC, you must first download and install a JDBC driver for the database you want to connect to. Then, you can use the JDBC API to create a connection to the database, send SQL statements, and process the results.

Here's a simple example of how to use JDBC to connect to a database and execute a SELECT statement:

import java.sql.*;

public class JDBCExample {

  static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";  
  static final String DB_URL = "jdbc:mysql://localhost/test";

  static final String USER = "username";
  static final String PASS = "password";
  
  public static void main(String[] args) {
  Connection conn = null;
  Statement stmt = null;
  try{
     Class.forName("com.mysql.jdbc.Driver");

     System.out.println("Connecting to database...");
     conn = DriverManager.getConnection(DB_URL,USER,PASS);

     System.out.println("Creating statement...");
     stmt = conn.createStatement();
     String sql;
     sql = "SELECT id, first, last, age FROM Employees";
     ResultSet rs = stmt.executeQuery(sql);

     while(rs.next()){
        int id  = rs.getInt("id");
        int age = rs.getInt("age");
        String first = rs.getString("first");
        String last = rs.getString("last");

        System.out.print("ID: " + id);
        System.out.print(", Age: " + age);
        System.out.print(", First: " + first);
        System.out.println(", Last: " + last);
     }
     rs.close();
     stmt.close();
     conn.close();
  }catch(SQLException se){
     se.printStackTrace();
  }catch(Exception e){
     e.printStackTrace();
  }finally{
     try{
        if(stmt!=null)
           stmt.close();
     }catch(SQLException se2){
     }
     try{
        if(conn!=null)
           conn.close();
     }catch(SQLException se){
        se.printStackTrace();
     }
  }
  System.out.println("Goodbye!");

}

See Also

• Open Database Connectivity (ODBC)