Spring + Java 11 +Myb提斯：@许多在注释方法中被忽略

Question

我是Mybatis的新手，在获取@多的数据方面遇到了问题。

我有两个类，第二类对象的值是Set<>的第一类对象；

课程如下：

public class InformationObjectMergedWithCopyrights {

    private Long id;
    private String titleLt;
    private String accountingNumber;
    private String inventoryNumber;
    private Long referenceYear;
    private Long duration;
    private String propertyRights;

    private Set<BavicCredit> creditsList = new HashSet<>();
    
    getters/setters, constructor, toString...
}

public class BavicCredit {

    private Long id;
    private Long informationObjectId;
    private String bavicLabel;
    private String bavicRole;
    
        getters/setters, constructor, toString...
}

我有sql提供程序，它负责查询字符串：

public class InformationObjectSqlProvider {
    public String selectByInventoryNumberConditionAccountingNumber(InventoryNumberReportParamsDao reportParamsDao) {
        
        StringBuilder sql = new StringBuilder("SELECT " +
            "io.ID AS id, " +
            "io.TITLE_LT AS titleLt, " +
            "io.ACCOUNTING_NUMBER AS accountingNumber, " +
            "io.INVENTORY_NUMBER AS inventoryNumber, " +
            "io.REFERENCE_YEAR AS referenceYear, " +
            "io.DURATION AS duration, " +
            "cvt.NAME AS propertyRights  " +
            "FROM SCHEMA_ONE.INFORMATION_OBJECT io " +
            "INNER JOIN SCHEMA_ONE.COPYRIGHTS c ON c.INFORMATION_OBJECT_ID = io.ID " +
            "INNER JOIN SCHEMA_TWO.CLASSIFIER_VALUES cv2 ON c.PROPERTY_RIGHTS = cv2.CODE " +
            "INNER JOIN SCHEMA_TWO.CLASSIFIER_VALUE_TRANSLATIONS cvt ON cv2.ID = cvt.CLASSIFIER_VALUE_ID AND cvt.LANGUAGE_ID = 1 " +
            "WHERE io.INVENTORY_NUMBER = #{reportParamsDao.inventoryNumberCode} ORDER BY accountingNumber ASC");

        return sql.toString();
    }
}

最后，我创建了一个映射器：

@Mapper
public interface InformationObjectMapper {

    InformationObjectSqlProvider provider = new InformationObjectSqlProvider();


    @SelectProvider(type = InformationObjectSqlProvider.class, method = "selectByInventoryNumberConditionAccountingNumber")
    @Results(value = {
        @Result(property = "creditsList",
            column = "SCHEMA_ONE.INF_OBJ_CLASIFFIER.INFORMATION_OBJECT_ID",
            javaType = Set.class, many = @Many(select = "selectCredits"))
    })
    List<InformationObjectMergedWithCopyrights> selectByInventoryNumberConditionAccountingNumber(@Param("reportParamsDao") InventoryNumberReportParamsDao reportParamsDao);

    @Select("SELECT * FROM SCHEMA_ONE.INF_OBJ_CLASSIFIER ioc WHERE ioc.INFORMATION_OBJECT_ID = #{informationObjetId} AND ioc.\"TYPE\" = 'CREDIT' ")
    @Results(value = {
        @Result(property = "bavicLabel", column = "BAVIC_LABEL"),
        @Result(property = "bavicRole", column = "ROLE")
    })
    Set<BavicCredit> selectCredits(@Param("informationObjetId") Long informationObjetId);
}

我的问题是，这段代码不返回BavicCredit类的集合。Set总是空的，就像在第一个类中定义的一样。似乎根本没有调用selectCredits方法。外键存在于数据库中。我相信，我遗漏了一些小代码或属性映射。

Java 11，SpringBoot2.5.0，Mybatis Start2.2.0，数据库Oracle com.oracle.database.jdbc ojdbc8

提前谢谢。

我试过了MyBatis中的一对多关系，但仍然遗漏了一些东西

Answer 1

当使用嵌套的select 1时，column属性的值应该是第一个查询结果集中的列名。

在第一个查询的结果集中，嵌套查询的参数是id，因此@Result应该如下所示。

@Result(
  property = "creditsList",
  column = "id",
  javaType = Set.class,
  many = @Many(select = "selectCredits"))

1有关基本知识，请阅读文档的部分。