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Im我的應用程序正在使用的數據庫中刪除單個項目以刪除問題。我知道該方法被調用，但是我的列表中沒有任何內容被刪除。我沒有得到任何錯誤，這使得追查很難。援助會很棒。SQlite刪除功能不會刪除條目
public class MainActivity extends Activity{
//Global Variables
ListView lv;
Intent addM, viewM;
public DBAdapter movieDatabase;
String tempTitle, tempYear;
int request_Code = 1;
int request_code2 = 2;
SimpleCursorAdapter dataAdapter;
Cursor cursor;
Button addButton;
long testID;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//creates the database
movieDatabase = new DBAdapter(this);
movieDatabase.open();
//movieDatabase.deleteAllMovies();
//creates the intents to start the sub activities
addM = new Intent(this, AddMovie.class);
viewM = new Intent(this, MovieView.class);
}
//handles the return of the activity addMovie
public void onActivityResult(int requestCode, int resultCode,
Intent data)
{
super.onActivityResult(requestCode, resultCode, data);
if(resultCode == RESULT_OK)
{
switch(requestCode)
{
case 1:
dbAddMovie(data.getStringExtra("title"),
data.getStringExtra("year"));
break;
case 2:
testID = data.getLongExtra("rowid", -1);
dMovie(testID);
break;
}
}
}
//adds item to the movie list
public void dbAddMovie(String mT, String mY)
{
movieDatabase.open();
movieDatabase.insertMovie(mT, mY);
Toast.makeText(this, "Movie: " + mT + " added to database",
Toast.LENGTH_SHORT).show();
}
//deletes an entry into the database
public void dMovie(long rowid)
{
//Toast.makeText(this, "Deleting: " + rowid,
Toast.LENGTH_SHORT).show();
movieDatabase.deleteMovie(rowid);
movieDatabase.getAllMovies();
}
//displays the database as a list
public void displayListView()
{
addButton = (Button) findViewById(R.id.add);
addButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
startActivityForResult(addM, 1);
}
});
cursor = movieDatabase.getAllMovies();
//columns to use
String[] columns = new String[]
{
movieDatabase.KEY_TITLE,
};
//xml data to bind the data to
int[] to = new int[]
{
R.id.column2,
};
//adapter to display the database as a list
dataAdapter = new SimpleCursorAdapter(this,
R.layout.complexrow, cursor, columns, to, 0);
//gets the List view resource
lv = (ListView) findViewById(R.id.movielist);
//sets the list view to use the adapter
lv.setAdapter(dataAdapter);
//handles the list click events
lv.setOnItemClickListener(new
AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View
v, int position,
long id) {
Cursor cursor = (Cursor)
parent.getItemAtPosition(position);
Bundle mDet = new Bundle();
mDet.putString("title",
cursor.getString(cursor.getColumnIndex(movieDatabase.KEY_TITLE)));
mDet.putString("year",
cursor.getString(cursor.getColumnIndex(movieDatabase.KEY_YEAR)));
mDet.putInt("rId", position);
viewM.putExtras(mDet);
startActivityForResult(viewM, 2);
}
});
//dataAdapter.notifyDataSetChanged();
}
public void onResume()
{
super.onResume();
displayListView();
}
}
和我coresponding將對DBAdapter類
public class DBAdapter {
public static final String KEY_ROWID = "_id";
public static final String KEY_TITLE = "title";
public static final String KEY_YEAR = "year";
private static final String TAG = "DBAdapter";
private static final String DATABASE_NAME = "MovieListDB";
private static final String DATABASE_TABLE = "MoviesTable";
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_CREATE = "create table MoviesTable (_id
integer primary key autoincrement, " +
"title text not null, year not null);";
private final Context context;
private DatabaseHelper DBHelper;
private SQLiteDatabase db;
public DBAdapter(Context ctx)
{
this.context = ctx;
DBHelper = new DatabaseHelper(context);
}
private static class DatabaseHelper extends SQLiteOpenHelper
{
DatabaseHelper(Context context)
{
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
try{
db.execSQL(DATABASE_CREATE);
} catch (SQLException e)
{
e.printStackTrace();
}
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
+ newVersion +
"which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS MoviesTable");
onCreate(db);
}
}
public DBAdapter open() throws SQLException
{
db = DBHelper.getWritableDatabase();
return this;
}
public void close()
{
DBHelper.close();
}
public long insertMovie(String title, String year)
{
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_TITLE, title);
initialValues.put(KEY_YEAR, year);
return db.insert(DATABASE_TABLE, null, initialValues);
}
public boolean deleteMovie(long rowID)
{
return db.delete(DATABASE_TABLE, KEY_ROWID + "='" + rowID+"'", null) >-1;
}
public Cursor getAllMovies()
{
return db.query(DATABASE_TABLE, new String[] {KEY_ROWID, KEY_TITLE,
KEY_YEAR}, null, null, null, null, null);
}
public Cursor getMovie(long rowID) throws SQLException
{
Cursor mCursor =
db.query(true, DATABASE_TABLE, new String[] {KEY_ROWID,
KEY_TITLE, KEY_YEAR}, KEY_ROWID + "=" + rowID, null, null, null, null, null);
if(mCursor != null)
{
mCursor.moveToFirst();
}
return mCursor;
}
public boolean updateContact(long rowID, String title, String year)
{
ContentValues args = new ContentValues();
args.put(KEY_TITLE, title);
args.put(KEY_YEAR, year);
return db.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowID, null) > 0;
}
public void deleteAllMovies() {
int doneDelete = 0;
doneDelete = db.delete(DATABASE_TABLE, null, null);
}
}
你說你知道它被調用...當被調用時'testID' /'rowid'的值是什麼？ – Geobits
它取決於我點擊的元素。我在dMovie中有一個吐司項目，它會根據我點擊的內容返回值。如果我將列表中的第一項打到最後一項，則範圍爲0 – user519670
能否從DBAdapter類發佈更多代碼？我假設它擴展了SQLiteOpenHelper？最重要的是，你調用getWritableDatabase（），而不是getReadableDatabase（）？ – Aaron