Merge "fix typo and clarify class references in database lesson bug: 9372560" into jb-mr1.1-ub-dev (343f581d) · Commits · e / os / android_frameworks_base

docs/html/training/basics/data-storage/databases.jd

+32 −34

Original line number	Original line	Diff line number	Diff line
	@@ -73,6 +73,12 @@ single table:</p>


	<pre>		<pre>
			public final class FeedReaderContract {
			// To prevent someone from accidentally instantiating the contract class,
			// give it an empty constructor.
			public FeedReaderContract() {}

			/* Inner class that defines the table contents */
	public static abstract class FeedEntry implements BaseColumns {		public static abstract class FeedEntry implements BaseColumns {
	public static final String TABLE_NAME = "entry";		public static final String TABLE_NAME = "entry";
	public static final String COLUMN_NAME_ENTRY_ID = "entryid";		public static final String COLUMN_NAME_ENTRY_ID = "entryid";
	@@ -80,15 +86,7 @@ public static abstract class FeedEntry implements BaseColumns {
	public static final String COLUMN_NAME_SUBTITLE = "subtitle";		public static final String COLUMN_NAME_SUBTITLE = "subtitle";
	...		...
	}		}
	</pre>		}


	<p>To prevent someone from accidentally instantiating the contract class, give
	it an empty constructor. </p>

	<pre>
	// Prevents the FeedReaderContract class from being instantiated.
	private FeedReaderContract() {}
	</pre>		</pre>


	@@ -103,15 +101,15 @@ statements that create and delete a table:</P>
	private static final String TEXT_TYPE = " TEXT";		private static final String TEXT_TYPE = " TEXT";
	private static final String COMMA_SEP = ",";		private static final String COMMA_SEP = ",";
	private static final String SQL_CREATE_ENTRIES =		private static final String SQL_CREATE_ENTRIES =
	"CREATE TABLE " + FeedReaderContract.FeedEntry.TABLE_NAME + " (" +		"CREATE TABLE " + FeedEntry.TABLE_NAME + " (" +
	FeedReaderContract.FeedEntry._ID + " INTEGER PRIMARY KEY," +		FeedEntry._ID + " INTEGER PRIMARY KEY," +
	FeedReaderContract.FeedEntry.COLUMN_NAME_ENTRY_ID + TEXT_TYPE + COMMA_SEP +		FeedEntry.COLUMN_NAME_ENTRY_ID + TEXT_TYPE + COMMA_SEP +
	FeedReaderContract.FeedEntry.COLUMN_NAME_TITLE + TEXT_TYPE + COMMA_SEP +		FeedEntry.COLUMN_NAME_TITLE + TEXT_TYPE + COMMA_SEP +
	... // Any other options for the CREATE command		... // Any other options for the CREATE command
	" )";		" )";

	private static final String SQL_DELETE_ENTRIES =		private static final String SQL_DELETE_ENTRIES =
	"DROP TABLE IF EXISTS " + TABLE_NAME_ENTRIES;		"DROP TABLE IF EXISTS " + FeedEntry.TABLE_NAME;
	</pre>		</pre>

	<p>Just like files that you save on the device's <a		<p>Just like files that you save on the device's <a
	@@ -191,15 +189,15 @@ SQLiteDatabase db = mDbHelper.getWritableDatabase();

	// Create a new map of values, where column names are the keys		// Create a new map of values, where column names are the keys
	ContentValues values = new ContentValues();		ContentValues values = new ContentValues();
	values.put(FeedReaderContract.FeedEntry.COLUMN_NAME_ENTRY_ID, id);		values.put(FeedEntry.COLUMN_NAME_ENTRY_ID, id);
	values.put(FeedReaderContract.FeedEntry.COLUMN_NAME_TITLE, title);		values.put(FeedEntry.COLUMN_NAME_TITLE, title);
	values.put(FeedReaderContract.FeedEntry.COLUMN_NAME_CONTENT, content);		values.put(FeedEntry.COLUMN_NAME_CONTENT, content);

	// Insert the new row, returning the primary key value of the new row		// Insert the new row, returning the primary key value of the new row
	long newRowId;		long newRowId;
	newRowId = db.insert(		newRowId = db.insert(
	FeedReaderContract.FeedEntry.TABLE_NAME,		FeedEntry.TABLE_NAME,
	FeedReaderContract.FeedEntry.COLUMN_NAME_NULLABLE,		FeedEntry.COLUMN_NAME_NULLABLE,
	values);		values);
	</pre>		</pre>

	@@ -227,18 +225,18 @@ SQLiteDatabase db = mDbHelper.getReadableDatabase();
	// Define a <em>projection</em> that specifies which columns from the database		// Define a <em>projection</em> that specifies which columns from the database
	// you will actually use after this query.		// you will actually use after this query.
	String[] projection = {		String[] projection = {
	FeedReaderContract.FeedEntry._ID,		FeedEntry._ID,
	FeedReaderContract.FeedEntry.COLUMN_NAME_TITLE,		FeedEntry.COLUMN_NAME_TITLE,
	FeedReaderContract.FeedEntry.COLUMN_NAME_UPDATED,		FeedEntry.COLUMN_NAME_UPDATED,
	...		...
	};		};

	// How you want the results sorted in the resulting Cursor		// How you want the results sorted in the resulting Cursor
	String sortOrder =		String sortOrder =
	FeedReaderContract.FeedEntry.COLUMN_NAME_UPDATED + " DESC";		FeedEntry.COLUMN_NAME_UPDATED + " DESC";

	Cursor c = db.query(		Cursor c = db.query(
	FeedReaderContract.FeedEntry.TABLE_NAME, // The table to query		FeedEntry.TABLE_NAME, // The table to query
	projection, // The columns to return		projection, // The columns to return
	selection, // The columns for the WHERE clause		selection, // The columns for the WHERE clause
	selectionArgs, // The values for the WHERE clause		selectionArgs, // The values for the WHERE clause
	@@ -262,7 +260,7 @@ For example:</p>
	<pre>		<pre>
	cursor.moveToFirst();		cursor.moveToFirst();
	long itemId = cursor.getLong(		long itemId = cursor.getLong(
	cursor.getColumnIndexOrThrow(FeedReaderContract.FeedEntry._ID)		cursor.getColumnIndexOrThrow(FeedEntry._ID)
	);		);
	</pre>		</pre>

	@@ -282,7 +280,7 @@ immune to SQL injection.</p>

	<pre>		<pre>
	// Define 'where' part of query.		// Define 'where' part of query.
	String selection = FeedReaderContract.FeedEntry.COLUMN_NAME_ENTRY_ID + " LIKE ?";		String selection = FeedEntry.COLUMN_NAME_ENTRY_ID + " LIKE ?";
	// Specify arguments in placeholder order.		// Specify arguments in placeholder order.
	String[] selectionArgs = { String.valueOf(rowId) };		String[] selectionArgs = { String.valueOf(rowId) };
	// Issue SQL statement.		// Issue SQL statement.
	@@ -305,10 +303,10 @@ SQLiteDatabase db = mDbHelper.getReadableDatabase();

	// New value for one column		// New value for one column
	ContentValues values = new ContentValues();		ContentValues values = new ContentValues();
	values.put(FeedReaderContract.FeedEntry.COLUMN_NAME_TITLE, title);		values.put(FeedEntry.COLUMN_NAME_TITLE, title);

	// Which row to update, based on the ID		// Which row to update, based on the ID
	String selection = FeedReaderContract.FeedEntry.COLUMN_NAME_ENTRY_ID + " LIKE ?";		String selection = FeedEntry.COLUMN_NAME_ENTRY_ID + " LIKE ?";
	String[] selectionArgs = { String.valueOf(rowId) };		String[] selectionArgs = { String.valueOf(rowId) };

	int count = db.update(		int count = db.update(