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So, so far we've used a very trivial example of accessing data,

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where we open the database, grab the data and then close it again.

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What do we do in the situation of needing more complex data retrieval?

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Let's go through and look at other ways that we can access data in our apps. So firstly, the problem

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might be that we're accessing a database when the user re-orientates their device, say from portrait

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to landscape,

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or they might press Home and access another app.

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Potentially we could have corrupted data because the Lifecycle doesn't have any idea about the database

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being accessed.

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So what we can do is we can effectively open our database once, and then query or re-query the data as needed,

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and only close the database when the Activity is destroyed.

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So in other words, we want the Lifecycle to be aware of the database. Then we can do things like binding to

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a view on the screen, for example

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We can also do it manually.

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So we can add code to each life cycle event to do the relevant thing for our database,

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for example, close it when the activity is closed etc. And it means that we're adding a lot of code to

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each screen in our app by doing it that way.

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AsyncTask is another way, so we can write some code to use these tasks any time we want to access

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the database, but that ends up being a lot of code.

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So that brings us to Content Provider.

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Now this is actually a standard way to provide access to a structured set of data -

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sqlite's a good example of this.

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So Content Providers are a core feature of Android Development.

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So we set up a Content Provider in our app, and then we can provide a mechanism to return the results

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to the calling process -

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our app, or any other app

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if we choose to share the provider's data.

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Now we don't technically need a Content Provider

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if you don't intend to share data, but I feel it's better to do it this way

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so your app is set up the right way in the event that you do decide to share the data in the future.

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Now Android provides us with a good list of built in Content providers for audio, video, images etc. and

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we will work more on those in future videos.

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My recommendation is to use a Content Provider for all your database projects because it adds more flexibility,

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and when it comes down to it, it's not much, if any, more complex than other methods.

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Alright, so I think at this point it's now time to put together an app. So the app's going to define a Content

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Provider and use a Cursor Loader to allow us to maintain our contacts database - add your contacts, edit and/or

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delete existing contacts, as well as displaying them.

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So let's start work on that in the next video.