javaweb入门(使用SQLserver2008 R2数据库)

一.数据库的使用

1 加载驱动

try {
            
        Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver").newInstance();
            
    } catch (InstantiationException | IllegalAccessException | ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
    }

2.创建链接对象

String user = "sa";
String password = "jisuan@10Q";
String url = "jdbc:sqlserver://localhost:1433;DatabaseName=jaovo_msg";
Connection connection = null;
try {
     connection = DriverManager.getConnection(url,user,password);
            
    } catch (SQLException e) {
            
      e.printStackTrace();
    }

3 创建语句传输对象

String sql = "select count(*) from t_login where username=? And password = ?";
PreparedStatement preparedStatement = null;3 4 preparedStatement = connection.prepareStatement(sql);

4 接收结果集对象

ResultSet resultSet = null;

resultSet = preparedStatement.executeQuery();

5 遍历

while(resultSet.next()) 
{
    if (resultSet.getInt(1) > 0) 
    {
           system.ou.println("就是这个！");
           return;
    }
}
                        

6 关闭资源

DBUtil.close(resultSet);
DBUtil.close(preparedStatement);
DBUtil.close(connection);