如何在 Spring Boot 中编写存储库查询以通过关联键进行过滤？

Question

How do you write a query in a repository interface to do a WHERE assoc_id = :key?

I have an entity called CmsImpacts , and then I have a service that calls the ImpactsRepository which looks like this:

    import java.util.List;
    
    public interface ImpactsRepository<T extends CmsImpacts> extends BaseCmsRepository<CmsImpacts> {
        
        @Query("SELECT a FROM #{#entityName} a where a.scenarioId = :scenarioId")
        List<CmsImpacts> getByScenarioPaged(
                Integer scenarioId,
                Pageable pageable
        );
        
        @Query("SELECT COUNT(a.id) FROM #{#entityName} a where a.scenarioId = :scenarioId")
        Integer getAsScenarioCount(
                Integer scenarioId
        );
        
        
        
    }

The gist of this relationship is that CmsScenarios is a one to many on CmsImpacts . The entity relation is defined as:

    
    @JsonIgnore
    @JsonBackReference
    @JoinColumn(name = "scenario_id", referencedColumnName = "id")
    @ManyToOne(optional = false, fetch = FetchType.LAZY)
    private CmsScenarios scenarioId;

Whenever I call my service and pass in the Integer value of the scenario_id, it throws a TypeException because (rightfully so), expects a CmsScenario object, not an Integer.

Error Message : 2020-11-04 15:10:45.764 ERROR 128396 --- [io-8080-exec-18] osbwservlet.support.ErrorPageFilter : Forwarding to error page from request [/api/impacts/list/scenario/2] due to exception [org.springframework.dao.InvalidDataAccessApiUsageException: Parameter value [2] did not match expected type [com.vw.asa.entities.cms.CmsScenarios (n/a)]; nested exception is java.lang.IllegalArgumentException: Parameter value [2] did not match expected type [com.vw.asa.entities.cms.CmsScenarios (n/a)]]

What do I need to do in order to execute this query? This applies to the query above it also, the Paginated counter.

Note:

I do not want to just retrieve the CmsScenarios object and call getImpacts() , that would return all objects, and I need to be able to paginate over them.

Answer 1

您必须添加相关实体的 id

@Query("SELECT a FROM #{#entityName} a where a.scenarioId.id = :scenarioId")