jdbc数据库连接

jdbc提供了一套统一操作各种数据库规范的接口
入门示例
加载驱动
获取连接
根据连接对象获取执行SQL语句，遍历

public class addressDao {
    public static void main(String[] args)  {
        try {
            Class.forName("com.mysql.jdbc.Driver");
            String url="jdbc:mysql://127.0.0.1:3306/smbms";
            Connection connection = DriverManager.getConnection(url, "root", "root");
            Statement statement = connection.createStatement();
            String sql="SELECt * FROM smbms_address";
            ResultSet resultSet = statement.executeQuery(sql);
            while (resultSet.next()){
                int id = resultSet.getInt("id");
                String contact = resultSet.getString("contact");
                String addressDesc = resultSet.getString("addressDesc");
                String postCode = resultSet.getString("postCode");
                String tel = resultSet.getString("tel");
                System.out.println("id"+id+"联系人是："+contact+"地址"+addressDesc+"邮编"+postCode+"电话"+tel);
            }
//            关闭资源
            resultSet.close();
            statement.close();
            connection.close();

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}

try {
            Class.forName("com.mysql.jdbc.Driver");
            String url="jdbc:mysql://127.0.0.1:3306/smbms";
            Connection connection = DriverManager.getConnection(url, "root", "root");
            Statement statement = connection.createStatement();
            String sql="SELECt * FROM smbms_user";
            ResultSet resultSet = statement.executeQuery(sql);
            while (resultSet.next()){
                int id = resultSet.getInt("id");
                String contact = resultSet.getString("userCode");
                String addressDesc = resultSet.getString("userName");
                String postCode = resultSet.getString("gender");
                String tel = resultSet.getString("phone");
                System.out.println("id"+id+"联系人是："+contact+"地址"+addressDesc+"邮编"+postCode+"电话"+tel);
            }
//            关闭资源
            resultSet.close();
            statement.close();
            connection.close();

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

statement对象
解决SQL注入问题
使用 preparestatement对象
SQL 语句

 try {
            Class.forName("com.mysql.jdbc.Driver");
            String url="jdbc:mysql://127.0.0.1:3306/smbms";
            Connection connection = DriverManager.getConnection(url, "root", "root");
//            Statement statement =
            String sql="SELECt * FROM smbms_address";
            PreparedStatement preparedStatement = connection.prepareStatement(sql);

            ResultSet resultSet = preparedStatement.executeQuery();
            while (resultSet.next()){
                int id = resultSet.getInt("id");
                String contact = resultSet.getString("contact");
                String addressDesc = resultSet.getString("addressDesc");
                String postCode = resultSet.getString("postCode");
                String tel = resultSet.getString("tel");
                System.out.println("id"+id+"联系人是："+contact+"地址"+addressDesc+"邮编"+postCode+"电话"+tel);
            }
//            关闭资源
            resultSet.close();
            preparedStatement.close();
            connection.close();

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

 try {
            Class.forName("com.mysql.jdbc.Driver");
            String url="jdbc:mysql://127.0.0.1:3306/smbms";
            Connection connection = DriverManager.getConnection(url, "root", "root");
//            Statement statement = connection.createStatement();
            String sql="SELECt * FROM smbms_user";

            PreparedStatement preparedStatement = connection.prepareStatement(sql);
            ResultSet resultSet = preparedStatement.executeQuery();
            while (resultSet.next()){
                int id = resultSet.getInt("id");
                String contact = resultSet.getString("userCode");
                String addressDesc = resultSet.getString("userName");
                String postCode = resultSet.getString("gender");
                String tel = resultSet.getString("phone");
                System.out.println("id"+id+"联系人是："+contact+"地址"+addressDesc+"邮编"+postCode+"电话"+tel);
            }
//            关闭资源
            resultSet.close();
            preparedStatement.close();
            connection.close();

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

增删改 ：executeUpdate