Android Tutorial

By : Ketan Bhimani

340 

Updating Records

Inserting data isn’t the only change you can make. You can update

one or more rows, as well. The following block of code shows how

to update data within a content provider. In this case, we update a

note field for a specific contact, using its unique identifier.

ContentValues values = new ContentValues();
values.put(People.NOTES, “This is my boss”);
Uri updateUri = ContentUris.withAppendedId(People.CONTENT_URI,
rowId);
int rows = getContentResolver().update(updateUri, values, null,
null);
Log.d(debugTag, “Rows updated: “ + rows);

Again, we use an instance of the ContentValues object to map the

data field we want to update with the data value—in this case, the

note field. This replaces any current note stored in the NOTES field

currently stored with the contact. We then create the Uri for the

specific contact we are updating. A simple call to the update()

method of the Content Resolver class completes our change. We

can then confirm that only one row was updated.

Deleting Records

Now that you cluttered up your contacts application with sample

user data, you might want to delete some of it. Deleting data is

fairly straightforward.

Deleting All Records

The following code deletes all rows at the given URI, although you

should execute operations like this with extreme care:

int rows = getContentResolver().delete(People.CONTENT_URI, null,
null);
Log.d(debugTag, “Rows: “+ rows);