Android™ Application Development - Bahar Ali Khan

Chapter 6: Data Storage, Retrieval, and Sharing
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}
}
int newVersion) {
Log.w(TAG, “Upgrading database from version “ + oldVersion + “ to “
+ newVersion + “, which will destroy all old data”);
db.execSQL(“DROP TABLE IF EXISTS “ + EARTHQUAKE_TABLE);
onCreate(db);
4. Create a UriMatcher to handle requests using different URIs. Include support for queries and
transactions over the entire data set (QUAKES) and a single record matching a quake index value
(QUAKE_ID).
// Create the constants used to differentiate between the different URI
// requests.
private static final int QUAKES = 1;
private static final int QUAKE_ID = 2;
private static final UriMatcher uriMatcher;
// Allocate the UriMatcher object, where a URI ending in ‘earthquakes’
// will correspond to a request for all earthquakes, and ‘earthquakes’
// with a trailing ‘/[rowID]’ will represent a single earthquake row.
static {
uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
uriMatcher.addURI(“com.paad.provider.Earthquake”, “earthquakes”,
QUAKES);
uriMatcher.addURI(“com.paad.provider.Earthquake”, “earthquakes/#”,
QUAKE_ID);
}
5. Override the getType method to return a String for each of the URI structures supported.
@Override
public String getType(Uri uri) {
switch (uriMatcher.match(uri)) {
case QUAKES:
return “vnd.android.cursor.dir/vnd.paad.earthquake”;
case QUAKE_ID:
return “vnd.android.cursor.item/vnd.paad.earthquake”;
default:
throw new IllegalArgumentException(“Unsupported URI: “ + uri);
}
}
6. Override the provider’s onCreate handler to create a new instance of the database helper class
and open a connection to the database.
@Override
public boolean onCreate() {
Context context = getContext();
earthquakeDatabaseHelper dbHelper;
dbHelper = new earthquakeDatabaseHelper(context, DATABASE_NAME, null,
DATABASE_VERSION);