问题描述
我有很多EntityManager，每个模式都有一个(我使用entity-mappings文件将EM映射到模式).可以.
I have many EntityManager, one per schema that I have (I use entity-mappings file to map EMs with schemas). It works.
当我使用@NamedQuery时，它的工作方式就像一种魅力，但是当我使用@NamedNativeQuery时，则不使用架构.我必须具备SELECT foo FROM schema.table的资格.
When I use @NamedQuery it's working like a charm but when I use @NamedNativeQuery schema is not used. I have to qualify with it SELECT foo FROM schema.table.
这是正确的行为吗?
我认为无法通过参数@NamedNativeQuery动态传递模式(我相信只有列可以是动态的，而不能是表或模式或其他任何东西)，那么我如何将@NamedNativeQuery与动态模式一起使用?
I think it's not possible to parameter @NamedNativeQuery to dynamically pass schema (I believe only columns can be dynamics not tables or schemas or anything else) so how can I use @NamedNativeQuery with dynamic schema please ?
推荐答案
文档摘录:
- NamedNativeQuery:指定一个命名的本机SQL查询.查询名称的作用域是持久性单元.
- NamedQuery:用Java Persistence查询语言指定静态的命名查询.查询名称的作用域是持久性单元.
- NamedNativeQuery : Specifies a named native SQL query. Query names are scoped to the persistence unit.
- NamedQuery : Specifies a static, named query in the Java Persistence query language. Query names are scoped to the persistence unit.
没有直接指定NamedNativeQuery是静态的，但是两者的作用域都相同&此后不能更改这是期望的行为.
It isn't specified directly that NamedNativeQuery is static, but both are same scoped & can't be altered afterwards & it's the desired behaviour.
命名查询意味着可以被多个模块访问-应用程序范围内，由唯一名称标识，因此它们是静态&持续的.您可以尝试动态创建查询字符串&可以从中创建本地查询，而不是命名本地查询.
Named queries are mean to be accessed by multiple modules - application wide, identified by unique name, so they are static & constant. You can try building a query string dynamically & can create a native query from it, instead of named native query.
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