Table of Contents
A transaction exactly belongs to one database.
Every DO should belong to a transaction. DOs without transaction exist only for the compatibility with the old DODS.
If a DO belongs to a transaction, the transaction in the DO can not be changed, and the DO can only be used in this transaction. Otherwise, DODS throws an exception.
A DO that belongs to no transaction can not be "attached" to a transaction. This kind of a DO at least belongs to a database and can only be used in this database. Otherwise, DODS throws an exception.
A DO has getTransaction() method that returns its own transaction if has one, or returns null otherwise.