OrmLite：Dao.callBatchTasks() 和 TransactionManager.callInTransaction() 之间的区别

Question

这些方法有什么区别？我已经阅读了文档，但我不明白 callBatchTasks 方法的作用。文档说：

This will turn off what databases call "auto-commit" mode, run the call-able and then re-enable "auto-commit".

这不是交易吗？

谢谢。

Answer 1

Difference between Dao.callBatchTasks() and TransactionManager.callInTransaction()

差异取决于您使用的数据库。 Android下没有区别。 callBatchTasks(...) 的 javadocs 说：

Call the call-able that will perform a number of batch tasks. This is for performance when you want to run a number of database operations at once -- maybe loading data from a file. This will turn off what databases call "auto-commit" mode, run the call-able, and then re-enable "auto-commit". If auto-commit is not supported then a transaction will be used instead.

Android的SQLite是数据库之一。在内部 ORMLite 代码中，您会看到：

private <CT> CT doCallBatchTasks(DatabaseConnection connection, boolean saved,
        Callable<CT> callable) throws SQLException {
    if (databaseType.isBatchUseTransaction()) {
        return TransactionManager.callInTransaction(connection, saved, databaseType,
            callable);
    }
    ...

所以在内部，当在 Android 下使用时，dao.callBatchTasks(...) 是对 TransactionManager.callInTransaction(...) 的调用。