oracle hibernate.jpa.criteria.BasicPathUsageException：无法加入基本类型的属性
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hibernate.jpa.criteria.BasicPathUsageException: Cannot join to attribute of basic type
提问by Avinash
I have two tables: Taxand TaxRule. There is one column same in both table i.e TAX_RULE_ID. But don't have any Hibernate mapping like OneToOneor OneToMany. Both table looks like-
我有两个表：Tax和TaxRule。两个表中有一列相同，即TAX_RULE_ID. 但是没有像OneToOne或那样的任何 Hibernate 映射OneToMany。两张桌子看起来都像-
TAX
税
@Id
@Column(name = "TAX_RATE_ID")
private Long taxRateId;
@Column(name = "TAX_RULE_ID")
private Long taxRuleId;
@Column(name = "TAX_TYPE")
private String taxType;
TAX_RULE
TAX_RULE
@Id
@Column(name = "TAX_RULE_ID")
private Long taxRuleId;
@Column(name = "TAX_CD")
private String TaxCode;
@Column(name = "STATE")
private String state;
I am trying to fetch data on the key i.e TAX_RULE_ID. This column is common in both table.
I have following Hibernatecode in which I am joining both table on the TAX_RULE_IDcolumn as follows:
我正在尝试获取密钥 ie 上的数据TAX_RULE_ID。此列在两个表中都是通用的。我有以下Hibernate代码，我在TAX_RULE_ID列中加入两个表，如下所示：
CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
CriteriaQuery<String[]> cQuery = criteriaBuilder.createQuery(String[].class);
Root<Tax> taxRoot = cQuery.from(Tax.class);
cQuery.multiselect(taxRateRoot.get("taxType"), taxRateRoot.get("taxRate"));
List<Predicate> predicates = new ArrayList<>();
Join<Tax, TaxRule> join = taxRoot.join("taxRuleId");
.....rest of the code.
I am getting following Exception on the join point:
我在连接点上收到以下异常：
org.hibernate.jpa.criteria.BasicPathUsageException: Cannot join to attribute of basic type
at org.hibernate.jpa.criteria.path.AbstractFromImpl.constructJoin(AbstractFromImpl.java:270)
at org.hibernate.jpa.criteria.path.AbstractFromImpl.join(AbstractFromImpl.java:263)
at org.hibernate.jpa.criteria.path.AbstractFromImpl.join(AbstractFromImpl.java:436)
at com.iclsystems.base.dao.TaxRateDAOImpl.getTaxTypeForApplicableWorkOrderTax(TaxRateDAOImpl.java:31)
at com.iclsystems.base.businessObjects.TaxLookupBOImpl.getTaxTypeForApplicableWorkOrderTax(TaxLookupBOImpl.java:53)
at com.iclsystems.base.businessObjects.TaxLookupBOImpl.getWorkOrderTaxLookup(TaxLookupBOImpl.java:29)
at com.iclsystems.test.eventhandler.base.TaxLookupBOTest.testTaxLookupBO(TaxLookupBOTest.java:52)
回答by Vlad Mihalcea
You cannot join a basic property (e.g., an attribute with a simple @Columnmapping). Join is for associations:
您不能加入基本属性（例如，具有简单@Column映射的属性）。加入是为协会：
- one-to-one
- one-to-many
- many-to-one
- many-to-many
- 一对一
- 一对多
- 多对一
- 多对多
You need to remove this line, as the taxRuleIdis already fetched from the database:
您需要删除这一行，因为taxRuleId已经从数据库中获取了：
Join<Tax, TaxRule> join = taxRoot.join("taxRuleId");
If you want to join the TaxRule table, you need to replace the:
如果要加入TaxRule表，需要替换：
@Column(name = "TAX_RULE_ID")
private Long taxRuleId;
with a many-to-one association:
多对一关联：
@ManyToOne
@JoinColumn(name = "TAX_RULE_ID")
private TaxRule raxRule;
