通过列表视图选择时，无法删除和更新SQLite数据库中的条目

Question

我的应用程序类似于todo应用程序，其中待办事项列表与标记相关联 例如： tag1：“星期天”    待办事项列表：任务：“唤醒迟到”信息：“task1”               任务：“快速突破”信息：“task2”

tag2：“星期一”    待办事项清单：任务：“6点起床”信息：“早醒”               任务：“阅读新闻报纸”信息：“task2”               任务：“吃快点”信息：“task3”

当用户选择一个标签（比如星期日）时，我正在制作该标签的待办事项列表，并在我的片段中将其显示为列表视图。列表视图中的每个条目都显示任务和信息详细信息。

现在我在每个列表条目上实施长按，并显示选项“删除条目”和“更新信息”。

对于“删除”操作，我已从数据库中删除该条目并显示列表更新列表视图。

对于“更新信息”，读取用户输入并更新“信息”详细信息并刷新列表视图。

我能够实现除数据库操作之外的所有操作，例如，如果用户选择删除并使用给定信息更新特定行，则删除相应的行。

我正在接受帮助     http://www.androidhive.info/2013/09/android-sqlite-database-with-multiple-tables/

对名称进行一些修改（不是逻辑）

但是有些删除和更新如何使用KEY_ID。

以下是创建表格的代码：

    public class DatabaseHelper extends SQLiteOpenHelper {

        private static final String CREATE_TABLE_ROWDATA = "CREATE TABLE IF NOT EXISTS "
        + TABLE_ROWDATA + "(" + KEY_ID + " INTEGER PRIMARY KEY," + KEY_ROWDATA
        + " TEXT," + KEY_INFOPATH + " TEXT," + KEY_STATUS + " INTEGER," + KEY_CREATED_AT
        + " DATETIME" + ")";

// CategoryTag table create statement
private static final String CREATE_TABLE_TAG = "CREATE TABLE IF NOT EXISTS " + TABLE_TAG
        + "(" + KEY_ID + " INTEGER PRIMARY KEY," + KEY_TAG_NAME + " TEXT,"
        + KEY_CREATED_AT + " DATETIME" + ")";

// rowdata_tag table create statement
private static final String CREATE_TABLE_ROWDATA_TAG = "CREATE TABLE IF NOT EXISTS "
        + TABLE_ROWDATA_TAG + "(" + KEY_ID + " INTEGER PRIMARY KEY,"
        + KEY_ROWDATA_ID + " INTEGER," + KEY_TAG_ID + " INTEGER,"
        + KEY_CREATED_AT + " DATETIME" + ")";

    public static DatabaseHelper sInstance;
        public static synchronized DatabaseHelper getInstance(Context context) {
    if (sInstance == null) {
        sInstance = new DatabaseHelper(context.getApplicationContext());
    }
    return sInstance;
}

@Override
public void onCreate(SQLiteDatabase db) {

    // creating required tables
    db.execSQL(CREATE_TABLE_ROWDATA);
    db.execSQL(CREATE_TABLE_TAG);
    db.execSQL(CREATE_TABLE_ROWDATA_TAG);
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    // on upgrade drop older tables
    db.execSQL("DROP TABLE IF EXISTS " + TABLE_ROWDATA);
    db.execSQL("DROP TABLE IF EXISTS " + TABLE_TAG);
    db.execSQL("DROP TABLE IF EXISTS " + TABLE_ROWDATA_TAG);

    // create new tables
    onCreate(db);
}

// ------------------------ "rowdatas" table methods ----------------//

/**
 * Creating a rowdata
 */
public long createRowData(RowData rowdata, long[] tag_ids) {
    SQLiteDatabase db = this.getWritableDatabase();

    ContentValues values = new ContentValues();
    values.put(KEY_ROWDATA, rowdata.getPath());
    values.put(KEY_INFOPATH, rowdata.getInfoPath());
    values.put(KEY_STATUS, rowdata.getStatus());
    values.put(KEY_CREATED_AT, getDateTime());

    // insert row
    long rowdata_id = db.insert(TABLE_ROWDATA, null, values);
    Log.e(LOG, "New rowdata id for: " + rowdata.getPath() + "is: " + rowdata_id + "tag id: " + tag_ids[0] + " to table: " + TABLE_ROWDATA);

    // insert tag_ids
    for (long tag_id : tag_ids) {
        createRowDataTag(rowdata_id, tag_id);
    }

    return rowdata_id;
}

/**
 * get single rowdata
 */
public RowData getRowData(long rowdata_id) {
    SQLiteDatabase db = this.getReadableDatabase();

    String selectQuery = "SELECT  * FROM " + TABLE_ROWDATA + " WHERE "
            + KEY_ID + " = " + rowdata_id;

    Log.e(LOG, selectQuery);

    Cursor c = db.rawQuery(selectQuery, null);

    if (c != null)
        c.moveToFirst();

    RowData td = new RowData();
    td.setId(c.getInt(c.getColumnIndex(KEY_ID)));
    td.setPath((c.getString(c.getColumnIndex(KEY_ROWDATA))));
    td.setInfoNote((c.getString(c.getColumnIndex(KEY_INFOPATH))));
    td.setCreatedAt(c.getString(c.getColumnIndex(KEY_CREATED_AT)));
    return td;
}

/**
 * getting all rowdatas
 * */
public List<RowData> getAllRowDatas() {
    List<RowData> rowdatas = new ArrayList<RowData>();
    String selectQuery = "SELECT  * FROM " + TABLE_ROWDATA;

    Log.e(LOG, selectQuery);

    SQLiteDatabase db = this.getReadableDatabase();
    Cursor c = db.rawQuery(selectQuery, null);

    // looping through all rows and adding to list
    if (c.moveToFirst()) {
        do {
            RowData td = new RowData();
            td.setId(c.getInt((c.getColumnIndex(KEY_ID))));
            td.setPath((c.getString(c.getColumnIndex(KEY_ROWDATA))));
            td.setInfoNote((c.getString(c.getColumnIndex(KEY_INFOPATH))));
            td.setCreatedAt(c.getString(c.getColumnIndex(KEY_CREATED_AT)));

            // adding to rowdata list
            rowdatas.add(td);
        } while (c.moveToNext());
    }
    return rowdatas;
}

/**
 * getting all rowdatas under single tag
 * */
public List<RowData> getAllRowDatasByCategoryTag(String tag_name) {
    List<RowData> rowdatas = new ArrayList<RowData>();

    String selectQuery = "SELECT  * FROM " + TABLE_ROWDATA + " td, "
            + TABLE_TAG + " tg, " + TABLE_ROWDATA_TAG + " tt WHERE tg."
            + KEY_TAG_NAME + " = '" + tag_name + "'" + " AND tg." + KEY_ID
            + " = " + "tt." + KEY_TAG_ID + " AND td." + KEY_ID + " = "
            + "tt." + KEY_ROWDATA_ID;

    Log.e(LOG, selectQuery);

    SQLiteDatabase db = this.getReadableDatabase();
    Cursor c = db.rawQuery(selectQuery, null);

    // looping through all rows and adding to list
    if (c.moveToFirst()) {
        do {
            RowData td = new RowData();
            td.setId(c.getInt((c.getColumnIndex(KEY_ID))));
            td.setPath((c.getString(c.getColumnIndex(KEY_ROWDATA))));
            td.setInfoNote((c.getString(c.getColumnIndex(KEY_INFOPATH))));
            td.setCreatedAt(c.getString(c.getColumnIndex(KEY_CREATED_AT)));

            // adding to rowdata list
            rowdatas.add(td);
        } while (c.moveToNext());
    }
    return rowdatas;
}

public RowData getRowDataId(String tag_name, RowData rowdata) {

    String selectQuery = "SELECT  * FROM " + TABLE_ROWDATA + " td, "
            + TABLE_TAG + " tg, " + TABLE_ROWDATA_TAG + " tt WHERE tg."
            + KEY_TAG_NAME + " = '" + tag_name + "'" + " AND tg." + KEY_ID
            + " = " + "tt." + KEY_TAG_ID + " AND td." + KEY_ID + " = "
            + "tt." + KEY_ROWDATA_ID;

    SQLiteDatabase db = this.getReadableDatabase();
    Cursor c = db.rawQuery(selectQuery, null);

    // looping through all rows and adding to list
    if (c.moveToFirst()) {
        do {
            if(rowdata.getPath().equals(c.getString(c.getColumnIndex(KEY_ROWDATA)))) {
                rowdata.setId(c.getColumnIndex(KEY_ID));
                rowdata.setInfoNote(c.getString(c.getColumnIndex(KEY_INFOPATH)));
                rowdata.setCreatedAt(c.getString(c.getColumnIndex(KEY_CREATED_AT)));
                break;
            }
        } while (c.moveToNext());
    }
    Log.e(LOG, rowdata.getPath() + " got id: " + rowdata.getId());
    return rowdata;
}
/**
 * getting rowdata count
 */
public int getRowDataCount() {
    String countQuery = "SELECT  * FROM " + TABLE_ROWDATA;
    SQLiteDatabase db = this.getReadableDatabase();
    Cursor cursor = db.rawQuery(countQuery, null);

    int count = cursor.getCount();
    cursor.close();

    // return count
    return count;
}

/**
 * Updating a rowdata
 */
public int updateRowData(RowData rowdata) {
    SQLiteDatabase db = this.getWritableDatabase();

    ContentValues values = new ContentValues();
    values.put(KEY_ROWDATA, rowdata.getPath());
    values.put(KEY_INFOPATH, rowdata.getInfoPath());
    values.put(KEY_STATUS, rowdata.getStatus());

    // updating row
    return db.update(TABLE_ROWDATA, values, KEY_ID + " = ?",
            new String[] { String.valueOf(rowdata.getId()) });
}

public int getRowDataCountByCategoryTag(String tag_name) {
    String selectQuery = "SELECT  * FROM " + TABLE_ROWDATA + " td, "
            + TABLE_TAG + " tg, " + TABLE_ROWDATA_TAG + " tt WHERE tg."
            + KEY_TAG_NAME + " = '" + tag_name + "'" + " AND tg." + KEY_ID
            + " = " + "tt." + KEY_TAG_ID + " AND td." + KEY_ID + " = "
            + "tt." + KEY_ROWDATA_ID;

    SQLiteDatabase db = this.getReadableDatabase();
    Cursor c = db.rawQuery(selectQuery, null);
    int count = c.getCount();
    return count;
}
/**
 * Deleting a rowdata
 */
public void deleteRowData(long todo_id) {
    SQLiteDatabase db = this.getWritableDatabase();
    Log.e(LOG, "Deleting rowdata id: " + todo_id + " from table: " + TABLE_ROWDATA);
    int ret = db.delete(TABLE_ROWDATA, KEY_ID + " = ?",
            new String[] { String.valueOf(todo_id) });

}

// ------------------------ "tags" table methods ----------------//

/**
 * Creating tag
 */
public long createCategoryTag(CategoryTag tag) {
    SQLiteDatabase db = this.getWritableDatabase();

    ContentValues values = new ContentValues();
    values.put(KEY_TAG_NAME, tag.getTagName());
    values.put(KEY_CREATED_AT, getDateTime());

    // insert row
    long tag_id = db.insert(TABLE_TAG, null, values);

    return tag_id;
}

public String[] getAllCategoryTagNames() {
    String[] tagNames = null;
    int count = 0;
    String selectQuery = "SELECT  * FROM " + TABLE_TAG;

    Log.e(LOG, selectQuery);

    SQLiteDatabase db = this.getReadableDatabase();
    Cursor c = db.rawQuery(selectQuery, null);
    tagNames = new String[c.getCount()];
    // looping through all rows and adding to list
    if (c.moveToFirst()) {
        do {
            tagNames[count] = c.getString(c.getColumnIndex(KEY_TAG_NAME));
            count++;
        } while (c.moveToNext());
    }
    return tagNames;
}
/**
 * getting all tags
 * */
public List<CategoryTag> getAllCategoryTags() {
    List<CategoryTag> tags = new ArrayList<CategoryTag>();
    String selectQuery = "SELECT  * FROM " + TABLE_TAG;

    Log.e(LOG, selectQuery);

    SQLiteDatabase db = this.getReadableDatabase();
    Cursor c = db.rawQuery(selectQuery, null);

    // looping through all rows and adding to list
    if (c.moveToFirst()) {
        do {
            CategoryTag t = new CategoryTag();
            t.setId(c.getInt((c.getColumnIndex(KEY_ID))));
            t.setTagName(c.getString(c.getColumnIndex(KEY_TAG_NAME)));

            // adding to tags list
            tags.add(t);
        } while (c.moveToNext());
    }
    return tags;
}

public CategoryTag getCategoryTagId(CategoryTag tag) {
    String selectQuery = "SELECT  * FROM " + TABLE_TAG;
    boolean found = false;
    Log.e(LOG, selectQuery);

    SQLiteDatabase db = this.getReadableDatabase();
    Cursor c = db.rawQuery(selectQuery, null);

    // looping through all rows and adding to list
    if (c.moveToFirst()) {
        do {
            if(c.getString(c.getColumnIndex(KEY_TAG_NAME)).equals(tag.getTagName())) {
                tag.setId(c.getInt((c.getColumnIndex(KEY_ID))));
                found = true;
                break;
            }
        } while (c.moveToNext());
    }
    if(found) {
        return tag;
    } else {
        tag.setId(-1);
        return tag;
    }
}

/**
 * Updating a tag
 */
public int updateCategoryTag(CategoryTag tag) {
    SQLiteDatabase db = this.getWritableDatabase();

    ContentValues values = new ContentValues();
    values.put(KEY_TAG_NAME, tag.getTagName());

    // updating row
    return db.update(TABLE_TAG, values, KEY_ID + " = ?",
            new String[] { String.valueOf(tag.getId()) });
}

/**
 * Deleting a tag
 */
public void deleteCategoryTag(CategoryTag tag, boolean should_delete_all_tag_rowdatas) {
    SQLiteDatabase db = this.getWritableDatabase();

    // before deleting tag
    // check if rowdatas under this tag should also be deleted
    if (should_delete_all_tag_rowdatas) {
        // get all rowdatas under this tag
        List<RowData> allTagToDos = getAllRowDatasByCategoryTag(tag.getTagName());

        // delete all rowdatas
        for (RowData rowdata : allTagToDos) {
            // delete rowdata
            deleteRowData(rowdata.getId());
        }
    }

    // now delete the tag
    db.delete(TABLE_TAG, KEY_ID + " = ?",
            new String[] { String.valueOf(tag.getId()) });
}

// ------------------------ "rowdata_tags" table methods ----------------//

/**
 * Creating rowdata_tag
 */
public long createRowDataTag(long rowdata_id, long tag_id) {
    SQLiteDatabase db = this.getWritableDatabase();

    ContentValues values = new ContentValues();
    values.put(KEY_ROWDATA_ID, rowdata_id);
    values.put(KEY_TAG_ID, tag_id);
    values.put(KEY_CREATED_AT, getDateTime());
    Log.e(LOG, "Inserting rowdata_id: " + rowdata_id + " tag id: " + tag_id + " to table: " + TABLE_ROWDATA_TAG);
    long id = db.insert(TABLE_ROWDATA_TAG, null, values);
    Log.e(LOG, "inserted id: " + id);
    return id;
}

public void printRowData_Tag() {
    String selectQuery = "SELECT  * FROM " + TABLE_ROWDATA_TAG;
    Log.e(LOG, selectQuery);

    SQLiteDatabase db = this.getReadableDatabase();
    Cursor c = db.rawQuery(selectQuery, null);

    // looping through all rows and adding to list
    if (c.moveToFirst()) {
        do {
            Log.e(LOG, TABLE_ROWDATA_TAG + "tag id: " + c.getInt(c.getColumnIndex(KEY_TAG_ID)) + "rowdata id: " + c.getInt(c.getColumnIndex(KEY_ROWDATA_ID)));
        }while (c.moveToNext());
    }
}
/**
 * Updating a rowdata tag
 */
public int updateRowData_Tag(long id, long tag_id) {
    SQLiteDatabase db = this.getWritableDatabase();

    ContentValues values = new ContentValues();
    values.put(KEY_TAG_ID, tag_id);

    // updating row
    return db.update(TABLE_ROWDATA_TAG, values, KEY_ID + " = ?",
            new String[] { String.valueOf(id) });
}

/**
 * Deleting a rowdata tag
 */
public void deleteRowData_Tag(long id) {
    SQLiteDatabase db = this.getWritableDatabase();
    Log.e(LOG, "Deleting id: " + id + " from : " + TABLE_ROWDATA_TAG);
    db.delete(TABLE_ROWDATA_TAG, KEY_ID + " = ?",
            new String[] { String.valueOf(id) });
}

// closing database
public void closeDB() {
    SQLiteDatabase db = this.getReadableDatabase();
    if (db != null && db.isOpen())
        db.close();
}

/**
 * get datetime
 * */
private String getDateTime() {
    SimpleDateFormat dateFormat = new SimpleDateFormat(
            "yyyy-MM-dd HH:mm:ss", Locale.getDefault());
    Date date = new Date();
    return dateFormat.format(date);
}
}

我可以在TABLE_ROWDATA中创建条目 我无法删除TABLE_ROWDATA中的条目 下面调用删除条目和更新列表视图的代码：

        public void deleteListEntry(int position) {
    CategoryTag tag = new CategoryTag(title);
    tag = db.getCategoryTagId(tag);
    RowData rowdata = new RowData(pathList[position], 0);
    List<RowData> rowdatas = db.getAllRowDatasByCategoryTag(title);
    for (RowData rd : rowdatas) {
        if (rd.getPath().equals(pathList[position])) {
            db.deleteRowData(rd.getId());
            break;
        }
    }
    Log.e("tagIt", "Count: " + db.getRowDataCountByCategoryTag(title));
}
public void updateRowDataList(){
    List<RowData> rowdatas = db.getAllRowDatasByCategoryTag(title);
    int i = 0;
    if(rowdatas.size() == 0) {
        Log.e("tagIt", "No list found ");
    }
    pathList = new String[rowdatas.size()];
    pathInfoList = new String[rowdatas.size()];
    for (RowData rowdata : rowdatas) {
        pathList[i] = rowdata.getPath();
        pathInfoList[i] = rowdata.getInfoPath();
        Log.e("tagIt", "rowdata-id: " + rowdata.getId());
        i++;
    }
}
public  View updateFragmentWithData(){
    updateRowDataList();
    lpadapter = new ListPathsAdapter(getActivity(), pathList, pathInfoList);
    lv = (ListView) rootView.findViewById(R.id.pathsList);
    lv.setAdapter(lpadapter);

    lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position,
                                long id) {
            openFile(position);
            return;
        }
    });
    registerForContextMenu(lv);
    return rootView;
}


        public  void updateInfo(final int position) {
    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
    builder.setTitle("Update info");
    final EditText input = new EditText(getActivity());
    builder.setView(input);
    builder.setPositiveButton("YES", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            dialog.dismiss();
            String value = input.getText().toString();
            CategoryTag tag = new CategoryTag(value);
            List<RowData> rowdatas = db.getAllRowDatasByCategoryTag(title);
            int i = 0;
            for(RowData rd : rowdatas){
                if (i == position){
                    rd.setInfoNote(value);
                    db.updateRowData(rd);
                    break;
                }
            }
            updateFragmentWithData();
        }
    });

以上删除调用来自onContextItemSelected（MenuItem item）;中的以下选择。其中info.position位于public String [] list pathList的列表条目中。

       @Override
public boolean onContextItemSelected(MenuItem item) {
    AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo) item.getMenuInfo();
    switch (item.getItemId()) {
        case R.id.send:
            openFile(info.position);
            return true;
        case R.id.delete:
            deleteListEntry(info.position);
            updateFragmentWithData();
            return true;
        case R.id.updateinfo:
            updateInfo(info.position);
            return true;
        default:
            return super.onContextItemSelected(item);
    }
}

我不确定DB中的问题在哪里。 db.delete返回0但删除后重新创建列表再次显示相同的列表。