十分有用的代码：JDBC连接DB2、Oracle、MySQL、PostgreSQL，并取当前时间

package com.terac.util;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.Statement;

public class DBTest {

public static void main(String[] args) {

try {

String user = "user";

String password = "password";

String driver = "COM.ibm.db2.jdbc.net.DB2Driver";

//"oracle.jdbc.driver.OracleDriver";

//"com.mysql.jdbc.Driver";

//"org.postgresql.Driver";

String url = "jdbc:db2://localhost/a";

//"jdbc:oracle:thin:@localhost:1521:a";

//"jdbc:mysql://localhost/a";

//"jdbc:postgresql://localhost:5740/a";

String sql = "SELECT current timestamp FROM sysibm.sysdummy1";

//"SELECT sysdate FROM dual";

//"SELECT now()";

//"SELECT current_timestamp";

Class.forName(driver).newInstance();

Connection c = DriverManager.getConnection(url, user, password);

Statement stmt = c.createStatement();

ResultSet rs = stmt.executeQuery(sql);

while (rs.next()) {

System.out.println(rs.getString(1));

}

} catch (Exception e) {

e.printStackTrace();

}

}

}