在java的应用中，我们经常会对数据库进行必要的操作，下来我们就了解一下如何用java连接mysql数据库 以及java连接sql server数据库

一、mysql

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

public class TestOne {

 private static Connection connection;
 private static Statement statement;
 private static ResultSet result;

 public static void main(String[] args) {
 try {
 //加载jdbc驱动程序
 Class.forName("com.mysql.jdbc.Driver");
 //指明主机名（默认为：127.0.0.1）和端口号（默认为：3306）以及数据库名（必须指定）
 String url = "jdbc:mysql://localhost:3306/test1";
 //与数据库建立连接
 connection = DriverManager.getConnection(url, "root", "123456");
 //创建一个Statement对象将SQL语句发送到数据库
 statement = connection.createStatement();
 //将查询结果返回给result
 result = statement.executeQuery("select *from user");
 while(result.next()){
 System.out.println("name:" + result.getString(1) + " password:" + result.getString(2));
 }
 connection.close();
 result.close();
 statement.close();
 } catch (ClassNotFoundException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 } catch (SQLException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 }finally{
 try {
 if(connection != null)
 connection.close();
 if(result != null)
 result.close();
 if(statement != null)
 statement.close();
 } catch (SQLException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 }
 }
 }
}
/**
 * mysql> select *from user;
 *+----------+----------+
 *| name | password |
 *+----------+----------+
 *| lisi | 123456 |
 *| wangwu | 123456 |
 *| zhangsan | 123456 |
 *+----------+----------+
 *3 rows in set (0.54 sec)
 *
 *在java中的

二、sql server

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

public class TestDemo {

 public static void main(String[] args) {
 String url="jdbc:sqlserver://localhost:1433;DatabaseName=Contellation";
 Connection conn = null;
 try {
 Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
 conn = DriverManager.getConnection(url, "sa", "");
 Statement statement=conn.createStatement();
 ResultSet rs = statement.executeQuery("select * from dbo.登陆表 ");
 while(rs.next()){
 System.out.println("用户名：" + rs.getString(1) + " 密码：" + rs.getString(2));
 }
 conn.close();
 } catch (ClassNotFoundException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 } catch (SQLException e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 } 
 }
}
/**
 * java中的