SQLResultSetMapping在出現空列時拋出異常

Question

我有一個值對象，我想要映射我的本機查詢結果集。 我使用@SQLResultSetMapping映射對象字段，但是當任何列的值是null，例外的是拋出：

Exception [EclipseLink-6177] (Eclipse Persistence Services - 2.6.1.v20150916-55dc7c3): org.eclipse.persistence.exceptions.QueryException 
Exception Description: The column result [custom_properties] was not found in the results of the query. 

我的實體類和映射

@Entity 
@Multitenant(MultitenantType.TABLE_PER_TENANT) 
@Table(name = "account_master") 
@SqlResultSetMapping(name = "DTO_MAPPING", classes = @ConstructorResult(
    targetClass = AccountDTO.class, 
    columns = {@ColumnResult(name = "id"), 
     @ColumnResult(name = "name"), 
     @ColumnResult(name = "custom_properties") 
    }) 
) 
public class Account implements Serializable { 
// fields, setters and getters 

} 

值對象：

public class AccountDTO { 

    public AssetDTO(){ 
    } 

    public AssetDTO(int id, String name, String customProperties) { 
    this.id = id; 
    this.name = name; 
    this.customProperties = customProperties; 
    } 

} 

執行語句

List<AccountDTO> accList = entityManager.createNativeQuery("SELECT id, name, custom_properties FROM account_master WHERE acc_hierarchy <@ 2.3", "DTO_MAPPING").getResultList() 

如果將custom_properties（可爲空）替換爲查詢中的靜態值，則映射完美無缺。實施有問題嗎？由於映射空值看起來像是一種常見的情況。

Answer 1

這在提交的EclipseLink作爲一個bug：https://bugs.eclipse.org/bugs/show_bug.cgi?id=484276

作爲一種變通方法，您可以在

@ColumnResult

註釋指定類型。

所以，你應該更改您的代碼：

@Entity 
@Multitenant(MultitenantType.TABLE_PER_TENANT) 
@Table(name = "account_master") 
@SqlResultSetMapping(name = "DTO_MAPPING", classes = @ConstructorResult(
    targetClass = AccountDTO.class, 
    columns = {@ColumnResult(name = "id"), 
     @ColumnResult(name = "name"), 
     @ColumnResult(name = "custom_properties", type=String.class) 
    }) 
) 
public class Account implements Serializable { 
// fields, setters and getters 

}