Java: Cách kết nối tới các RDBMS trong Java JDBC

package jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class SQLServerJDBCConnnection { //Bạn có quyền đặt tên lớp theo ý bạn

    static String hostName = "localhost";
    static String dbName = "dbsqlserver";
    static String userName = "sa";
    static String password = "1234";

    public static Connection getSQLServerJDBCConnection() throws SQLException {

        // Cấu trúc URL Connection dành cho SQLServer
        // Ví dụ:
        // jdbc:sqlserver://localhost:1433/databaseName=dbsqlserver
        String connectionURL = "jdbc:sqlserver://" + hostName + ":1433;databaseName=" + dbName;

        Connection conn = DriverManager.getConnection(connectionURL, userName, password);
        return conn;
    }
}

package jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class SQLServerJTDSConnection { //Bạn có quyền đặt tên lớp theo ý bạn

    static String hostName = "localhost";
    static String dbName = "dbjdbc";
    static String userName = "sa";
    static String password = "1234567";

    public static Connection getSQLServerJTDSConnection() throws SQLException {

        // Cấu trúc URL Connection dành cho SQLServer
        // Ví dụ: jdbc:jtds:sqlserver://localhost:1433/dbjdbc
        String connectionURL = "jdbc:jtds:sqlserver://" + hostName + ":1433/" + dbName;

        Connection conn = DriverManager.getConnection(connectionURL, userName, password);
        return conn;
    }
}

package jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class SQLServerODBCConnection {

    static String userName = "lab";
    static String password = "";

    public static Connection getSQLServerODBCConnection() throws SQLException {

        // Cấu trúc URL Connection dành cho JDBC-ODBC
        String connectionURL = "jdbc:odbc:driver={SQL Server}; Server=LAB54\\SQL2012; Database=DBLab8";
        Connection conn = DriverManager.getConnection(connectionURL, userName, password);
        return conn;
    }
}

package jdbc;

import java.sql.*;

class MySQLConnection { //Bạn có quyền đặt tên lớp theo ý bạn

  static String hostName = "localhost";
  static String dbName = "db_demo";
  static String userName = "root";
  static String password = "";

  public static Connection getMySQLConnection() throws SQLException, ClassNotFoundException {

    // Cấu trúc URL Connection dành cho MySQL
    // Ví dụ: jdbc:mysql://localhost:3306/db_demo
    Class.forName("com.mysql.jdbc.Driver");
    String connectionURL = "jdbc:mysql://" + hostName + ":3306/" + dbName;

    Connection conn = DriverManager.getConnection(connectionURL, userName, password);
    return conn;
  }
}

public class JDBC {
  public static void main(String[] args) throws SQLException, ClassNotFoundException {
    try {
      Connection con=MySQLConnection.getMySQLConnection();
      Statement stmt = con.createStatement();
      ResultSet rs = stmt.executeQuery("select * from category");
      while (rs.next()) {
        System.out.println(rs.getString(2)); //hiển thị dữ liệu của cột thứ 2
      }
      con.close();
    } catch (Exception e) {
      System.out.println(e);
    }
  }
}

package jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class OracleConnection { //Bạn có quyền đặt tên lớp theo ý bạn

    static String hostName = "localhost";
    static String sid = "db11g";
    static String userName = "dtlong";
    static String password = "";

    public static Connection getOracleConnection() throws SQLException {

        // Cấu trúc URL Connection dành cho Oracle
        // Ví dụ: jdbc:oracle:thin:@localhost:1521:db11g
        String connectionURL = "jdbc:oracle:thin:@" + hostName + ":1521:" + sid;

        Connection conn = DriverManager.getConnection(connectionURL, userName, password);
        return conn;
    }
}

package jdbc;

import java.sql.Connection;
import java.sql.SQLException;

public class TestConnection {

    public static void main(String[] args) throws SQLException {

        Connection conn = SQLServerJDBCConnnection.getSQLServerJDBCConnection();

        //SQLServer-JTDS: Connection conn = SQLServerJTDSConnection.getSQLServerJTDSConnection();

        //SQLServer-ODBC: Connection conn = SQLServerODBCConnection.getSQLServerODBCConnection();

        //MySQL: Connection conn = MySQLConnection.getMySQLConnection();

        //Oracle: Connection conn = OracleConnection.getOracleConnection();

        if(conn!=null)
            System.out.println("Kết nối thành công!");
    }
}