使用注解方式开发持久层接口

public interface IUserDao {
/**

• 查询所有用户
• @return

*/
@Select("select * from user")
@Results(id="userMap",
value= {
@Result(id=true,column="id",property="userId"),
@Result(column="username",property="userName"),
@Result(column="sex",property="userSex"),
@Result(column="address",property="userAddress"),
@Result(column="birthday",property="userBirthday")
})
List<User> findAll();

• 根据 id 查询一个用户
• @param userId
• @return

*/
@Select("select * from user where id = #{uid} ")
@ResultMap("userMap")
User findById(Integer userId);
/**

• 保存操作
• @param user
• @return

*/
@Insert("insert into
user(username,sex,birthday,address)values(#{username},#{sex},#{birthday},#{address}
)")
@SelectKey(keyColumn="id",keyProperty="id",resultType=Integer.class,before =
false, statement = { "select 1463865" })
int saveUser(User user);
/**

• 更新操作
• @param user
• @return

*/
@Update("update user set
username=#{username},address=#{address},sex=#{sex},birthday=#{birthday} where id
=#{id} ")
int updateUser(User user);
/**

• 删除用户
• @param userId
• @return

*/
@Delete("delete from user where id = #{uid} ")
int deleteUser(Integer userId);
/**

• 查询使用聚合函数
• @return

*/
@Select("select count(*) from user ")
int findTotal();