使用 Hibernate 将实体映射到物化视图

Question

我需要使用 Hibernate 将 (PostgreSQL) 实体化视图映射到 @Entity。如果 hbm2ddl 配置为 update 值，Hibernate 总是尝试创建新的 SQL table。只有当视图被物化时才会发生这种情况，否则（对于非物化视图）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 物化视图

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 hbm2ddl 选项配置为 validate 则抛出异常。

感谢您的帮助。

Answer 1

在这种情况下，您不应该使用 hibernate.hbm2ddl.auto。实际上，您应该始终喜欢使用 incrementing database scripts while having FlywayDB 自动执行数据库更新过程。

因为您使用特定于数据库的物化视图，休眠模式生成器根本无法帮助您。因此，您唯一的选择是特定于数据库的增量脚本。

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

这不是一个很好的解决方案，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模式，您应该看到。

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

而不是 @Table 使用 @Subselect("SELECT * FROM quasar_evaludated_function")

使用 Hibernate 将实体映射到物化视图

Mapping entity to a materialized view using Hibernate

java

sql

hibernate

postgresql

materialized-views