跨 DAO 的 Android Room 交易

Question

官方文档指出:

It is recommended to have multiple Dao classes in your codebase depending on the tables they touch.

并且可以用这样的 Transaction 注解来标记一个方法:

 @Dao
 public abstract class ProductDao {
    @Insert
     public abstract void insert(Product product);
    @Delete
     public abstract void delete(Product product);
    @Transaction
     public void insertAndDeleteInTransaction(Product newProduct, Product oldProduct) {
         // Anything inside this method runs in a single transaction.
         insert(newProduct);
         delete(oldProduct);
     }
 }

但是如果一个事务跨越多个 DAO 怎么办？我应该将所有 DAO 合并为一个以支持交易，还是有更好的方法来做到这一点？

Answer 1

您可以使用 RoomDatabase.runInTransaction(...)

类似于:

database.runInTransaction(new Runnable(){
  @Override
  public void run(){
    Access all your daos here
  }
});