问题描述
我一直在试图创造一个所有表,以继承某个元素数据库不得不可能性有元数据。
I've been trying to create a database where all the tables inherit a certain element in order to have to possibility to have meta-data.
有对我的模型生成器加入所有的表声明此行
there for I added in the model generator in all the table declarations this line:
public Entity addSuperEntity(Schema schema) {
Entity superEntity = schema.addEntity("superEntity");
superEntity.addIdProperty().primaryKey();
// SET RELATIONSHIP 1:m TO META DATA
}
public Entity addTable(Schema schema) {
Entity mEntity = schema.addEntity("MyEntity");
mEntity.setSuper("superEntity");
mEntity.addIdProperty().PrimaryKey();
// REST OF FIELDS
}
问题是:
现在我生成这个对我的Android项目后,我怎样才能确保这仍然发生在现实生活中?我现在需要改变什么?
now after I generated this to my Android project, how can I make sure that this still happens in real life? do I need to change anything now?
官方文档没有关于继承的东西。
the official documentation doesn't have anything about inheritance.
推荐答案
继承是支持使用setSuperclass(串)非实体超类。另一种方法是使用实现的implementsInterface(字符串)接口。
Inheritance is supported for non-entity super classes using setSuperclass(String). An alternative is implementing interfaces using implementsInterface(String).
我更新了关于继承和接口的新节的一些细节的官方文档:
http://greendao-orm.com/documentation/modelling-entities/
I updated the official docs with some details in the new section on inheritance and interfaces:http://greendao-orm.com/documentation/modelling-entities/
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