问题描述
这个表格是每月生成的.基本上所有月度表的表结构都是一样的.
There is this table that is being generated on a monthly basis. Basically the table structure of all monthly tables is the same.
因为只用不同的表名映射同一个实体需要很多工作，
Since it would be a lot of work to map the same entity just with a different table name,
实体的表名是否可以在运行时更改如下，因为它们毕竟具有相同的表结构?
Is it possible to change the table name of an entity as follows on runtime since they have the same table structure after all?
@Entity
@Table(name="FOO_JAN2010") // any other ways to generate this dynamically?
public class FooJan2010Table { // if we can dynamically set the table name this can be simply named FooTable
...
}
如果没有，您可以建议什么方法?
If not, what approach can you suggest?
推荐答案
这实际上是不可能的，至少在以下问题中提到的标准 JPA 不可能(这并不意味着我是用非标准 JPA 做到的):
This is not really possible, at least not with standard JPA (which doesn't mean I did it with non standard JPA) as mentioned in questions such as:
- 在@Table(name = "tableName") - 使tableName"成为 JPA 中的变量
- JPA: 运行时如何指定一个类对应的表名?
- Hibernate 或 iBatis 或其他什么?
总而言之，JPA 没有提供一种方法来改变"已经初始化的持久性单元的给定实体(以及相关的预编译 CRUD 查询、预编译命名查询等).
To summarize, JPA doesn't offer a way to "alter" a given entity of an already initialized persistence unit (and the related pre-compiled CRUD queries, the pre-compiled named queries, etc).
不过，由于您使用的是 Hibernate，不妨看看 http://www.hibernate.org/171.html 以了解使用 Hibernate Core API 的可能性.
Still, since you're using Hibernate, maybe have a look at http://www.hibernate.org/171.html to get an idea of what would be possible using Hibernate Core API.
我能想到的另一个选择是使用数据库同义词/别名:FOO 将是 FOO_JAN2010 的别名 直到...您将别名更改为指向 FOO_FEB2010.我从来没有测试过这个，我不知道它是否适合你的需求.但这是另一个想法.
Another option I can think of would be to use a database synonym / alias: FOO would be an alias for FOO_JAN2010 until... you change the alias to point on FOO_FEB2010. I've never tested this, I don't know if it will suit your needs. But it's another idea.
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