我有处理所有的数据插入和检索有关我的申请，我下面就谷歌I / O建议的维吉尔Dobjanschi模式ContentProvider的。我使用的是第一种模式。

I have a ContentProvider which handles all the data insertion and retrieval related to my application, I'm following the pattern suggested by Virgil Dobjanschi on Google I/O. I am using the first pattern.

我的问题是，我有一个重新由多个数据库中的表psented $ P $的逻辑实体。

My problem is that I have a logical entity that was represented by multiple tables in the database.

例如，我有一个文章表和ArticleExtras表。文章重新presents文章本身，而ArticleExtras重新presents对某些文章，如评论数addtional信息。

For example, I have an Articles table and an ArticleExtras table. Articles represents the article itself, while ArticleExtras represents addtional information about certain Article, like number of comments.

我用的CursorAdapter在UI中显示文章标题及该条评论中的ListView一行的数量。

I used CursorAdapter in the UI to display the Article title and the number of comments of that Article in one row of ListView.

要实现这一点，我添加了一个左外连接ArticleExtras上语句中的第表我的ContentProvider查询的方法，以便CursorAdapter的获得ArticleExtras与文章本身

To implement that, I added a left outer join ArticleExtras on statement in my ContentProvider query method for Article table, in order for CursorAdapter to get ArticleExtras along with the Article itself.

在新的文章是从网上获取的，我把它插入通过ContentProvider的数据库，然后CursorAdapter的得到了通知，并更新UI，这部分工作正常。

When new Articles are fetched from the web, I insert it into the database via ContentProvider, and then the CursorAdapter got notified and update the UI, this part worked as expected.

但是当我拿来的意见（ArticleExtras）的数量，我想同样的CursorAdapter，这是看的变化内容：//com.myapp.content/Articles ，被通知，也让我可以在ListView更新我行。

But when I fetched the number of comments (ArticleExtras), I want the same CursorAdapter, which is watching for changes in the content://com.myapp.content/Articles, to be notified, too, so I can update my row in the ListView.

我目前的执行情况是这样的：插入ArticleExtras到数据库后，我开始一个新的查询，以检查是否条表具有一个关系到我刚插入的ArticleExtras任何行。如果是的话，我会做一个新的URI为第（例如：内容：//com.myapp.cotent/Articles/123 ），并调用的getContext（）。getContentResolver（）。有NotifyChange（URI，空），这样在看这条修改相应的CursorAdapter会得到通知。

My current implementation is like this: After inserting ArticleExtras into the database, I start a new query to check if Articles table has any rows that is related to the ArticleExtras I just inserted. If so I'll make a new uri for that Article( for example: content://com.myapp.cotent/Articles/123), and call getContext().getContentResolver().notifyChange(uri, null), so the corresponding CursorAdapter that is watching for changes of this Article will get notified.

时的做法正确，或者是还有什么更好的办法来实现我想要什么？

Is the approach correct, or is there any better way to implement what I want?

推荐答案

结帐 ContactsProvider2 ，在它自己设置通知的URI的 AUTHORITY_URI 这似乎是一个包罗万象的所有在提供其他的URI。我有同样的probem，我已经试过此我自己的供应商有多个表和联接这些表，并能正常工作。

Checkout ContactsProvider2, in it they set the notification uri to the AUTHORITY_URI which appears to be a catch all for the other URIs in the provider. I had the same probem and I have tried this myself for a provider with multiple tables and joins on those tables, and it works fine.