SQLiteDatabase使用后关闭或不关闭-SQLiteDatabasetocloseornottocloseafterusing

1  

Despite what the documentation implies, there isn't really a relevant difference between getReadableDatabase() and getWritableDatabase(); both open the database, and that database stays open until it is close()d. So those examples are not correct; they should handle both cases in the same way.

尽管文档暗示了这一点,但getReadableDatabase()和getWritableDatabase()之间并没有真正的相关区别。都打开数据库,该数据库保持打开状态,直到它关闭()d。所以那些例子不正确;他们应该以同样的方式处理这两种情况。

Please note that "when you no longer need the database" does not necessarily mean that you need to close it after each query; if, for example, an activity is likely to access the database multiple times, it is perfectly valid to open it when the activity is started, and to close it when the activity is stopped.

请注意,“当您不再需要数据库时”并不一定意味着您需要在每次查询后关闭它;例如,如果活动可能多次访问数据库,则在活动启动时打开它是完全有效的,并且在活动停止时关闭它。

An open database connection reserves some memory for its cache, and the system stops activities if it needs more memory, so you should ensure that there is no open database when there is no active activity.

打开的数据库连接为其缓存保留一些内存,如果系统需要更多内存,系统将停止活动,因此在没有活动活动时应确保没有打开的数据库。

0  

You need to keep the database open as long as there are cursors in use that contain data from it. I myself rarely close the database, even when using getWriteableDatabase().

只要有正在使用的游标包含来自它的数据,您就需要保持数据库处于打开状态。即使使用getWriteableDatabase(),我自己也很少关闭数据库。

-1  

As per android documentation sqlite database Writable database "Once opened successfully, the database is cached, so you can call this method every time you need to write to the database. (Make sure to call close()when you no longer need the database.) Errors such as bad permissions or a full disk may cause this method to fail, but future attempts may succeed if the problem is fixed."

根据android文档sqlite数据库可写数据库“一旦成功打开,数据库就会被缓存,所以每次需要写入数据库时​​都可以调用此方法。(确保在不再需要数据库时调用close()。 )错误权限或完整磁盘等错误可能导致此方法失败,但如果问题得到解决,将来的尝试可能会成功。“

As the writable is cached as soon it's opened it means it will take up memory. And if database is large then huge memory , so not closing it or keeping it open may lead to member leaks.

由于writeable在打开后会被缓存,这意味着它会占用内存。如果数据库很大,那么巨大的内存,所以不关闭它或保持打开可能会导致成员泄漏。

Hope this helps you :)

希望这可以帮到你:)