Getting Error on Expand Function .

[suraj-mane-zellis]

I am using 2.0.0 release of odata jpa with spring boot 3.1.3 version . I have added OneToOne relationship into Location entity .

When I am use Expand , I am getting error

URL : http://host url/odata/Locations?$expand=Address

Response : {
"error": {
"code": null,
"message": "Could not determine recommended JdbcType for com.odata.entity.Address"
}
}

Sample Code :

  @Entity
  @Cacheable(false)
  @Table(name = "Location")
 public class Location {


@Id
@Column(name = "LocationId", nullable = false)
private Short locationId;

@Column(name = "AddressId")
private Integer addressId;

@OneToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "AddressId",referencedColumnName = "AddressId"
        insertable = false, updatable = false)
    private Address address;

//getters and setters

[wog48]

I was able to reproduce the error.

Before I explain what happens, I need to give a short introduction. OData allows to specify a type cast e.g. in navigations to address a derived type instead the base type given in the definition of the navigation property. As an example in the following test BusinessPartnerRoles(BusinessPartnerID='98',RoleCategory='X')/BusinessPartner/com.sap.olingo.jpa.Person can be taken. To support this, a type cast of a JPA From is done in JPAAbstractJoinQuery#createFromClauseNavigationJoins:

        final JPAEntityType cast = this.navigationInfo.get(i + 1).getEntityType();
        target = (From<?, ?>) target.as(cast.getTypeClass());

In fact this is not only done if a type cast is requested, but always, which should not be a problem. It runs well with various EclipseLink implementation (last tested with 4.0.2) as well as the own Criteria Builder implementation odata-jpa-processor-cb. Looking at OpenJPA implementation I am optimistic that it would work as well. Only Hibernate gave a problem. Here I used version 6.2.7, which came with Spring Boot 3.1.3.

The cast shall be done in SqmCriteriaNodeBuilder#cast. To get the type, the method calls
final BasicDomainType<X> type = getTypeConfiguration().standardBasicTypeForJavaType( castTargetJavaType );

TypeConfiguration#standardBasicTypeForJavaType look as follows:

		if ( javaType == null ) {
			return null;
		}

		return standardBasicTypeForJavaType(
				javaType,
				javaTypeDescriptor -> new BasicTypeImpl<>(
						javaTypeDescriptor,
						javaTypeDescriptor.getRecommendedJdbcType( getCurrentBaseSqlTypeIndicators() )
				)
		);

As Address is an entity the javaTypeDescriptor is an instance of EntityJavaType. The implementation of method getRecommendedJdbcType always throws an error.

This looks to me like an error in Hibernate and not in the JPA Processor. Therefor I close the issue.

[wog48]

It turned out, that there is also an error in the JPA Processor

[wog48]

Please have a look at version 2.0.2. In case you still face the problem, reopen this issue.