MyBatis的注解使用、ORM层优化方式(懒加载和缓存)

@Select( "SELECT * FROM tt_user WHERE username Like #{id};")
User findUserByName(String name);

<!--以map为输入参数查找-->
@Select("select * from tt_user where username= #{name} and  passWord=#{pass}")
User findUserByUsernameAndPassword(HashMap map);

@Insert("insert into tt_user values (#{id},#{username},#{password},#{email},#{age})")
int AddUser(User user) throws ioException;

@Update("update tt_user set username = #{username} where id = #{id}")
void updateUserById(User user);

@Delete("delete from tt_user where id =#{id}")
void deleteUserById(String id);

@SelectProvider(type = UserDaoSqlProvider.class,method = "findUserByName")
List<User> findUserByName(String username) throws IOException;

    public String findUserByName(String username){
        //return  "select * from tt_user where username like '" +username+"'";
        String sql = new SQL() {{
            SELECT("*");
            FROM("tt_user");
            if (username!=null&&!username.isEmpty()){
                WHERE("username like "+username );
            }
        }}.toString();
        System.out.println("sql="+sql);
        return sql;
}

    public String getxxx(){

       return new SQL().UPDATE("PERSON")
                 .SET("FULL_NAME = #{fullName}", "DATE_OF_BIRTH = #{dateOfBirth}")
                 .WHERE("ID = #{id}")
                 .toString();
    }
}

    <!--全局懒加载-->
    <settings>
        <!--开关-->
        <setting name="lazyLoadingEnabled" value="true"/>
    </settings>

    <resultMap id="studentAndCourses" type="com.bamzhy.bean.Student">
        <id column="id" property="id"></id>
        <collection property="courses"
                    javaType="list"
                    select="com.bamzhy.dao.UserDao.findcourseBySid"
                    column="id"
                    fetchType="eager">
            <id column="cid" property="cid"></id>
        </collection>
    </resultMap>