Question

我需要使用Hibernate将（PostgreSQL）物化视图映射到@Entity。如果hbm2ddl配置为update值，则Hibernate总是尝试创建新的SQL表。只有在视图具体化时才会发生这种情况，否则（使用非物化视图）它可以正常工作。

映射实体

@Entity
@Immutable
@Cache (usage=CacheConcurrencyStrategy.READ_ONLY)
@Table(name = "quasar_evaludated_function")
public class EvaluatedAuditor {

    private long id;

    private boolean qsAuditor;

    // getter setters ...

}

SQL MATERIALIZED VIEW

CREATE materialized VIEW quasar_evaludated_function
AS SELECT a.id AS id,
          (SELECT Count(code)
           FROM   quasar_qs_auditor_code code
           WHERE  code.auditor_id = a.id
                  AND code.is_granted = TRUE) > 0 AS is_qs_auditor
   FROM   quasar_auditor a;

日志

ERROR 2015-01-14 21:16:17 SchemaUpdate:execute(line 261) - HHH000388: Unsuccessful: create table quasar_evaludated_function (id int8 not null, is_clinical_expert boolean, is_product_assessor_a boolean, is_product_assessor_r boolean, is_product_specialist boolean, is_qs_auditor boolean, is_responsible_clinician boolean, is_technical_expert boolean, primary key (id))
ERROR 2015-01-14 21:16:17 SchemaUpdate:execute(line 262) - ERROR: relation "quasar_evaludated_function" already exists

如果配置为hbm2ddl的{{1}}选项被抛出异常。

感谢您的帮助。

Answer 1

在这种情况下，你不应该使用hibernate.hbm2ddl.auto。实际上，在incrementing database scripts自动执行数据库更新过程的同时，您应该始终使用FlywayDB。

因为您使用特定于数据库的实体化视图，所以hibernate架构生成器根本不会帮助您。因此，您唯一的选择是数据库特定的增量脚本。

您仍然可以为PostgreSQL和集成测试内存数据库（例如HSQLDB或H2）维护单独的脚本。

Answer 2

这不是很好的解决方案，但它确实有效。我刚刚创建了一个新视图，它引用了一个物化视图。如果您不需要自动生成图表，则应该看到 Vlad Mihalcea's solution 。

CREATE MATERIALIZED VIEW quasar_evaludated_function_mv AS select 
                a.id as id,
                (select count(f) from quasar_qs_auditor_code f where  f.auditor_id = a.id and f.is_granted = true) >  0 as is_qs_auditor,
                (select count(f) from quasar_product_assessor_a_code f where  f.auditor_id = a.id and f.is_granted = true) >  0 as is_product_assessor_a,
                (select count(f) from quasar_product_assessor_r_code f where  f.auditor_id = a.id and f.is_granted = true) >  0 as is_product_assessor_r, 
                (select count(f) from quasar_product_specialist_code f where  f.auditor_id = a.id and f.is_granted = true) >  0 as is_product_specialist,
                (select count(f) from quasar_technical_expert_code f where  f.auditor_id = a.id and f.is_granted = true) >  0 as is_technical_expert,
                (select count(f) from quasar_clinical_expert_code f where  f.auditor_id = a.id and f.is_granted = true) >  0 as is_clinical_expert, 
                (select count(f) from quasar_responsible_clinician_code f where  f.auditor_id = a.id and f.is_granted = true) >  0 as is_responsible_clinician
                from quasar_auditor a;

    CREATE VIEW quasar_evaludated_function  AS SELECT mv.* from quasar_evaludated_function_mv mv;

Answer 3

使用 @Table 代替 @Subselect("SELECT * FROM quasar_evaludated_function")

使用Hibernate将实体映射到物化视图

3 个答案: