使用 SQLiteOpenHelper 的 Android 和 SQLite
我有一个 SQLite 数据库，以及该数据库中的几个表。我正在为数据库中的每个表开发一个 DBAdapter。 （参考 Reto Meier 的专业 Android 2 应用程序开发，清单 7.1）。
我正在使用 adb shell 从命令行与数据库交互，并看到数据库正在按我的预期填充。有时，我想删除一个表，以便我可以确保它从头开始正确构建。
问题是 SQLiteOpenHelper 仅检查数据库是否存在。是否有一个典型的解决方案来编写一个助手来查看表是否存在？基本上，一旦我删除一个表，助手就会检查数据库是否存在并假设一切正常。
此外，上面参考中使用的 CREATE_DATABASE 字符串仅创建一个表。我是否应该考虑使用 DBAdapter 作为我所有表的适配器？这对我来说似乎不太干净。
I have a SQLite database, and several tables within that datbase. I am developing a DBAdapter for each table within the database. (reference Reto Meier's Professional Android 2 Application Development, Listing 7.1).
I am using the adb shell to interface with the database from the command line and see that the database is being populated as I expect. Occasionally, I want to drop a table so that I can ensure it's being built properly, from scratch.
The problem is that SQLiteOpenHelper only checks to see if the database exists. Is there a typical solution to writing a helper to also see that the table(s) exists? Basically once I drop a table, the helper checks to see that the database exists and assumes all is well.
Also, the CREATE_DATABASE string used in the reference above only creates the one table. Should I consider using the DBAdapter for an adapter to ALL of my tables? That doesn't seem as clean to me.
如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。
绑定邮箱获取回复消息
由于您还没有绑定你的真实邮箱，如果其他用户或者作者回复了您的评论，将不能在第一时间通知您！
发布评论
评论（2）
（用您的表名称替换
...）如果返回
1，则您的表存在。如果返回0，则您的表不存在。然而，助手不会帮助你。出于测试目的，我建议摆脱整个数据库，因为在生产中，您也不会动态创建单独的表。
(substituting in your table's name for
...)If that returns
1, your table exists. If that returns0, your table does not exist.However, the helper won't help you with that. For testing purposes, I recommend getting rid of the entire database, since in production, you won't be creating individual tables on the fly, either.
我有一个仪器测试，它会删除并重新创建所有表。多做一点工作，但一旦完成就会更有帮助。
除了 CommonsWare 建议之外，还有一个选项可以使用 shell 命令来获取此信息。
I have a instrumentation test which drops and recreates all tables. A little more work but once done a lot more helpful.
In addition to what CommonsWare suggested there is also a option to use shell command to get this informations.