mybatis-jpa

        <dependency>
            <groupId>com.littlenb</groupId>
            <artifactId>mybatis-jpa</artifactId>
            <version>2.1.2</version>
        </dependency>

<settings>
    <!-- default : false -->
		<setting name="mapUnderscoreToCamelCase" value="true" />
</settings>

<configuration>
    <plugins>
		<plugin interceptor="com.mybatis.jpa.plugin.ResultTypePlugin">
		</plugin>
	</plugins>
</configuration>

@Entity
public class UserArchive {// <resultMap id="xxx" type="userArchive">

    @Id
    private Long userId;// <id property="id" column="user_id" />
                           
    /** 默认驼峰与下划线转换 */
    private String userName;// <result property="username" column="user_name"/>

    /** 枚举类型 */
    @Enumerated(EnumType.ORDINAL)
    private SexEnum sex;// <result property="sex" column="sex" typeHandler=EnumOrdinalTypeHandler/>
    
    /** 枚举类型,自定义值 */
    @CodeEnum(CodeType.INT)
    private PoliticalEnum political;// <result property="political" column="political" typeHandler=IntCodeEnumTypeHandler/>
    
    /** 属性名与列名不一致 */
    @Column(name = "gmt_create")
    private Date createTime;// <result property="createTime" column="gmt_create"/>
}// </resultMap>

<!-- in xml,declare the resultType -->
<select id="selectById" resultType="userArchive">
	SELECT * FROM t_sys_user_archive WHERE user_id = #{userId}
</select>

@Service
public class DefinitionStatementInit {

    @Autowired
    private SqlSessionFactory sqlSessionFactory;

    @PostConstruct
    public void init() {
        Configuration configuration = sqlSessionFactory.getConfiguration();
        StatementBuildable statementBuildable = new DefinitionStatementBuilder(configuration);
        DefinitionStatementScanner.Builder builder = new DefinitionStatementScanner.Builder();
        DefinitionStatementScanner definitionStatementScanner = builder.configuration(configuration).basePackages(new String[]{"com.mybatis.jpa.mapper"})
                .statementBuilder(statementBuildable).build();
        definitionStatementScanner.scan();
    }
}

@Mapper
@Repository
public interface UserUpdateMapper {

    @InsertDefinition(selective = true)
    int insert(User user);

    @UpdateDefinition(selective = true, where = " user_id = #{userId}")
    int updateById(User user);
}