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am f0380a26: am 343f581d: Merge "fix typo and clarify class references in database lesson bug: 9372560" into jb-mr1.1-ub-dev

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* commit 'f0380a267c8ae9c351d5799752fe5fdb9b210800':
  fix typo and clarify class references in database lesson bug: 9372560
This commit is contained in:
Scott Main
2013-06-10 16:17:45 -07:00
committed by Android Git Automerger
parent a7ba45ec7c f0380a267c
commit d731c90240
1 changed files with 32 additions and 34 deletions
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66
docs/html/training/basics/data-storage/databases.jd
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@@ -73,25 +73,23 @@ single table:</p>
<pre>
public static abstract class FeedEntry implements BaseColumns {
public static final String TABLE_NAME = &quot;entry&quot;;
public static final String COLUMN_NAME_ENTRY_ID = &quot;entryid&quot;;
public static final String COLUMN_NAME_TITLE = &quot;title&quot;;
public static final String COLUMN_NAME_SUBTITLE = &quot;subtitle&quot;;
...
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 final String TABLE_NAME = &quot;entry&quot;;
public static final String COLUMN_NAME_ENTRY_ID = &quot;entryid&quot;;
public static final String COLUMN_NAME_TITLE = &quot;title&quot;;
public static final String COLUMN_NAME_SUBTITLE = &quot;subtitle&quot;;
...
}
}
</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>
<h2 id="DbHelper">Create a Database Using a SQL Helper</h2>
@@ -103,15 +101,15 @@ statements that create and delete a table:</P>
private static final String TEXT_TYPE = &quot; TEXT&quot;;
private static final String COMMA_SEP = &quot;,&quot;;
private static final String SQL_CREATE_ENTRIES =
&quot;CREATE TABLE &quot; + FeedReaderContract.FeedEntry.TABLE_NAME + &quot; (&quot; +
FeedReaderContract.FeedEntry._ID + &quot; INTEGER PRIMARY KEY,&quot; +
FeedReaderContract.FeedEntry.COLUMN_NAME_ENTRY_ID + TEXT_TYPE + COMMA_SEP +
FeedReaderContract.FeedEntry.COLUMN_NAME_TITLE + TEXT_TYPE + COMMA_SEP +
&quot;CREATE TABLE &quot; + FeedEntry.TABLE_NAME + &quot; (&quot; +
FeedEntry._ID + &quot; INTEGER PRIMARY KEY,&quot; +
FeedEntry.COLUMN_NAME_ENTRY_ID + TEXT_TYPE + COMMA_SEP +
FeedEntry.COLUMN_NAME_TITLE + TEXT_TYPE + COMMA_SEP +
... // Any other options for the CREATE command
&quot; )&quot;;
private static final String SQL_DELETE_ENTRIES =
&quot;DROP TABLE IF EXISTS &quot; + TABLE_NAME_ENTRIES;
&quot;DROP TABLE IF EXISTS &quot; + FeedEntry.TABLE_NAME;
</pre>
<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
ContentValues values = new ContentValues();
values.put(FeedReaderContract.FeedEntry.COLUMN_NAME_ENTRY_ID, id);
values.put(FeedReaderContract.FeedEntry.COLUMN_NAME_TITLE, title);
values.put(FeedReaderContract.FeedEntry.COLUMN_NAME_CONTENT, content);
values.put(FeedEntry.COLUMN_NAME_ENTRY_ID, id);
values.put(FeedEntry.COLUMN_NAME_TITLE, title);
values.put(FeedEntry.COLUMN_NAME_CONTENT, content);
// Insert the new row, returning the primary key value of the new row
long newRowId;
newRowId = db.insert(
FeedReaderContract.FeedEntry.TABLE_NAME,
FeedReaderContract.FeedEntry.COLUMN_NAME_NULLABLE,
FeedEntry.TABLE_NAME,
FeedEntry.COLUMN_NAME_NULLABLE,
values);
</pre>
@@ -227,18 +225,18 @@ SQLiteDatabase db = mDbHelper.getReadableDatabase();
// Define a <em>projection</em> that specifies which columns from the database
// you will actually use after this query.
String[] projection = {
FeedReaderContract.FeedEntry._ID,
FeedReaderContract.FeedEntry.COLUMN_NAME_TITLE,
FeedReaderContract.FeedEntry.COLUMN_NAME_UPDATED,
FeedEntry._ID,
FeedEntry.COLUMN_NAME_TITLE,
FeedEntry.COLUMN_NAME_UPDATED,
...
};
// How you want the results sorted in the resulting Cursor
String sortOrder =
FeedReaderContract.FeedEntry.COLUMN_NAME_UPDATED + " DESC";
FeedEntry.COLUMN_NAME_UPDATED + " DESC";
Cursor c = db.query(
FeedReaderContract.FeedEntry.TABLE_NAME, // The table to query
FeedEntry.TABLE_NAME, // The table to query
projection, // The columns to return
selection, // The columns for the WHERE clause
selectionArgs, // The values for the WHERE clause
@@ -262,7 +260,7 @@ For example:</p>
<pre>
cursor.moveToFirst();
long itemId = cursor.getLong(
cursor.getColumnIndexOrThrow(FeedReaderContract.FeedEntry._ID)
cursor.getColumnIndexOrThrow(FeedEntry._ID)
);
</pre>
@@ -282,7 +280,7 @@ immune to SQL injection.</p>
<pre>
// Define 'where' part of query.
String selection = FeedReaderContract.FeedEntry.COLUMN_NAME_ENTRY_ID + &quot; LIKE ?&quot;;
String selection = FeedEntry.COLUMN_NAME_ENTRY_ID + &quot; LIKE ?&quot;;
// Specify arguments in placeholder order.
String[] selectionArgs = { String.valueOf(rowId) };
// Issue SQL statement.
@@ -305,10 +303,10 @@ SQLiteDatabase db = mDbHelper.getReadableDatabase();
// New value for one column
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
String selection = FeedReaderContract.FeedEntry.COLUMN_NAME_ENTRY_ID + &quot; LIKE ?&quot;;
String selection = FeedEntry.COLUMN_NAME_ENTRY_ID + &quot; LIKE ?&quot;;
String[] selectionArgs = { String.valueOf(rowId) };
int count = db.update(