Question

我正在尝试通过SQLite获取数据。在我自定义的SimpleCursorAdapter中，我编写了以下bindView方法。

 @Override
 public void bindView(View _view, Context context, Cursor cursor) {

     //Get the properties of the todo item and create it.
     int indexOfTask;
     String task = null;
     int indexOfDeadline;
     Date deadline = null;
     int indexOfPriority;
     int priority = 0;
     int indexOfStatus;
     String status = null;


     indexOfTask=cursor.getColumnIndexOrThrow(ToDoListProvider.KEY_TASK);
     task=cursor.getString(indexOfTask);
     indexOfDeadline=cursor.getColumnIndexOrThrow(ToDoListProvider.KEY_DEADLINE);
     deadline=new Date(cursor.getLong(indexOfDeadline));
     indexOfStatus=cursor.getColumnIndexOrThrow(ToDoListProvider.KEY_STATUS);
     status=cursor.getString(indexOfStatus);

     indexOfPriority=cursor.getColumnIndexOrThrow(ToDoListProvider.KEY_PRIORITY);
     priority=cursor.getInt(indexOfPriority);



    TodoItem todo = new TodoItem(task, deadline);
             super.bindView(_view, context, cursor);
             }

在MainActivity类中，onCreate方法如下：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_todo_list);

    final ListView todoList = (ListView) findViewById(R.id.todoListView);
    final Button newTodoButton = (Button) findViewById(R.id.newTodoButton);


    todoAdapter = new TodoArrayAdapter(this,
            R.layout.todo_list_item, null,
            new String[] { ToDoListProvider.KEY_PRIORITY,                    ToDoListProvider.KEY_DEADLINE, ToDoListProvider.KEY_TASK,ToDoListProvider.KEY_STATUS},
            new int[] { R.id.todo_list_item_priority, R.id.todo_list_item_deadline, R.id.todo_list_item_task});
    todoList.setAdapter(todoAdapter);

    getLoaderManager().initLoader(0, null, this);

    newTodoButton.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent(TodoListActivity.this,
                    NewTodoActivity.class);
            startActivityForResult(intent, NEW_TODO_REQUEST);
        }
    });

    todoList.setOnItemClickListener(new OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {
            Intent intent = new Intent(TodoListActivity.this,
                    EditTodoActivity.class);
            intent.putExtra(TODO_ITEM_EXTRA, todoItems.get(position));
            intent.putExtra(TODO_ITEM_INDEX_EXTRA, position);
            startActivityForResult(intent, EDIT_TODO_REQUEST);
        }
    });
}

addTodoItem方法：

private void addTodoItem(TodoItem todo) {
    todoItems.add(todo);
    Collections.sort(todoItems);
    todoAdapter.notifyDataSetChanged();

    // Add a new student record
      ContentValues values = new ContentValues();

      values.put(ToDoListProvider.KEY_TASK, 
      todo.getTask());

      values.put(ToDoListProvider.KEY_DEADLINE, 
      todo.getDeadline().toString());

      values.put(ToDoListProvider.KEY_STATUS, 
              todo.getStatus().toString());

      values.put(ToDoListProvider.KEY_PRIORITY,
              todo.getPriority());

      Uri uri = getContentResolver().insert(
      ToDoListProvider.CONTENT_URI, values);


      }

我还写了ContentProvider类和DBHelper类。 ToDoListProvider类：

public class ToDoListProvider extends ContentProvider{
public static final Uri CONTENT_URI=Uri.parse("content://com.example.todolistprovider/todolistitems");

public static final String KEY_ID="_id";
public static final String KEY_DEADLINE="deadline";
public static final String KEY_TASK="task";
public static final String KEY_STATUS="status";
public static final String KEY_PRIORITY="priority";


private static class ToDoListDatabaseHelper extends SQLiteOpenHelper{
    private static final String TAG="ToDoListProvider";
    private static final String DATABASE_NAME="todolist.db";
    private static final int DATABASE_VERSION=1;
    private static final String TODOLIST_TABLE="todolist";
    private static final String DATABASE_CREATE="create table "
            + TODOLIST_TABLE + " (" + KEY_ID
            + " integer primary key autoincrement, " + KEY_DEADLINE
            + " DATE, " + KEY_TASK + " TEXT, " + KEY_STATUS
            + " TEXT, " + KEY_PRIORITY + " INTEGER);";




    private SQLiteDatabase todolistDB;

    public ToDoListDatabaseHelper(Context context,String name,CursorFactory factory,int version){
        super(context,name,factory,version);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(DATABASE_CREATE);

    }

    @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 "+ TODOLIST_TABLE);
        onCreate(db);
        }
}
private static final int TODOLISTITEMS=1;
private static final int TODOLISTITEM_ID=2;

private static final UriMatcher uriMatcher;

static {
    uriMatcher=new UriMatcher(UriMatcher.NO_MATCH);
    uriMatcher.addURI("tr.edu.iyte.arf.ceng389.todolistprovider",
            "todolistitems",TODOLISTITEMS);
    uriMatcher.addURI("tr.edu.iyte.arf.ceng389.todolistprovider",
            "todolistitems/#",TODOLISTITEM_ID);

}
ToDoListDatabaseHelper dbHelper;

@Override
public boolean onCreate() {
    Context context=getContext();
    dbHelper=new ToDoListDatabaseHelper(context,
            ToDoListDatabaseHelper.DATABASE_NAME,null,
            ToDoListDatabaseHelper.DATABASE_VERSION);
    return true;
} 

@Override
public String getType(Uri uri) {
    switch(uriMatcher.match(uri)){
    case TODOLISTITEMS:
        return "vnd.android.cursor.dir/vnd.iyte.todolistitems";
    case TODOLISTITEM_ID:
        return "vnd.android.cursor.item/vnd.iyte.todolistitem";
    default:
        throw new IllegalArgumentException("Unsupported URI: "+uri);

    }

}

@Override
public Cursor query(Uri uri, String[] projection, String selection,
        String[] selectionArgs, String sortOrder) {

    SQLiteDatabase database=dbHelper.getWritableDatabase();
    SQLiteQueryBuilder qb=new SQLiteQueryBuilder();
    qb.setTables(ToDoListDatabaseHelper.TODOLIST_TABLE);
    // If this is a row query, limit the result set to the passed in row.
    switch(uriMatcher.match(uri)){

    case TODOLISTITEM_ID:
        qb.appendWhere(KEY_ID+ "="+uri.getPathSegments().get(1));
        break;
    default:
        break;
    }
    // If no sort order is specified, sort by date / time
    String orderBy;
    if(TextUtils.isEmpty(sortOrder)){
        orderBy=KEY_PRIORITY;
    }
    else{
        orderBy=sortOrder;
    }
    // Apply the query to the underlying database.
    Cursor cursor=qb.query(database,projection,selection,selectionArgs,
            null,null,orderBy);
    // Register the contexts ContentResolver to be notified if
            // the cursor result set changes.
    cursor.setNotificationUri(getContext().getContentResolver(),uri);
    //Return a cursor to the query result.
    return cursor;
}


@Override
public Uri insert(Uri _uri, ContentValues values) {
    SQLiteDatabase database = dbHelper.getWritableDatabase();
    // Insert the new row. The call to database.insert will return the row
    // number
    // if it is successful.
    long rowID = database.insert(ToDoListDatabaseHelper.TODOLIST_TABLE,"todolistitem",values);
    // Return a URI to the newly inserted row on success.
    if (rowID > 0) {
        Uri uri = ContentUris.withAppendedId(CONTENT_URI, rowID);
        getContext().getContentResolver().notifyChange(uri, null);
        return uri;
    }

    //throw new SQLException("Failed to insert row into " + _uri);
    return _uri;
}

@Override
public int delete(Uri uri, String where, String[] whereArgs) {
    SQLiteDatabase database = dbHelper.getWritableDatabase();
    int count;
    switch (uriMatcher.match(uri)) {
    case TODOLISTITEMS:
        count = database.delete(ToDoListDatabaseHelper.TODOLIST_TABLE,
                where, whereArgs);
        break;
    case TODOLISTITEM_ID:
        String segment = uri.getPathSegments().get(1);
        count = database.delete(ToDoListDatabaseHelper.TODOLIST_TABLE,
                KEY_ID
                        + "="
                        + segment
                        + (!TextUtils.isEmpty(where) ? " AND (" + where
                                + ")" : ""), whereArgs);
        break;
    default:
        throw new IllegalArgumentException("Unsupported URI: " + uri);
    }
    getContext().getContentResolver().notifyChange(uri, null);
    return count;
}

当我运行应用程序时，ToDo任务，优先级和日期来到ListView但是当我想获取状态列时，我给出了以下错误：

       12-03 03:16:45.026: E/AndroidRuntime(3679): 
       java.lang.IllegalArgumentException:   column     'status' does not exist

       12-03 03:16:45.026: E/AndroidRuntime(3679):  at  
       android.database.AbstractCursor.getColumnIndexOrThrow(AbstractCursor.java:303)

Waht可能是造成这个错误的原因？我在互联网上搜索，发现没有找到任何有用的解决方案。任何帮助，将不胜感激。

Answer 1

由于您已实现LoaderManager.LoaderCallbacks，因此您需要确保始终使用您更新的任何列更新投影数组，这通常用于创建CursorLoader。对于您需要使用额外列的任何查询也是如此。

java.lang.IllegalArgumentException：列'status'不存在

1 个答案: