我正在使用Java persistance和实体Manager的班级,并负责储存一个将写给数据库的班级物体。 我的问题是,我想用同一个储存类别向不同的数据库书写。 我的解决方案是撰写一份储存手册,其中有一个包含所有实体管理者的地图。 在我研究数据库之前,解决办法是好的,并且认识到,所有信息(取决于地图,它具有正确的价值)都写给同一数据库(地图中首版)。
So my question is: Can I write to different databases using JPA that is using the same storage class (the class holding the structure of my database)?
增 编
我的解决方案是撰写一份储存手册,其中载有所有实体管理者的地图。
我不认为<代码>Map> 。
However, it should be possible to use
Persistence.createEntityManagerFactory(String, Map) to create N EntityManagerFactory pointing to N databases (the mentioned factory method allows to pass additional properties that override values that may have been configured elsewhere, for example a connection url) and to these EntityManagerFactory in a Map.
然后,从
是的,在<代码>persistence.xml中界定了多个持久性单位。 然后,在插入<条码>@PersistenceContext时。 具体列明<代码>unitName属性。
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