Question

我绝对是Android的初学者。现在我开始在我的教程项目中使用SQLite数据库。我尝试插入并选择数据。一切正常。但现在我第一次开始更新行。但是实际上没有在数据库中更新行。但它并没有抛出错误。

我的数据库助手类

public class DatabaseHelper extends SQLiteOpenHelper {

    private static final int DATABASE_VERSION = 1;
    private static final String DATABASE_NAME = "todo.db";
    private static final String TABLE_NAME = "task";
    private static final String COLUMN_ID = "id";
    private static final String COLUMN_DESCRIPTION = "description";
    private static final String COLUMN_DATE ="date";
    private static final String COLUMN_DONE = "done";
    private static final String CREATE_TABLE = "CREATE TABLE "+TABLE_NAME+" ("+COLUMN_ID+" INTEGER PRIMARY KEY AUTOINCREMENT,"+COLUMN_DESCRIPTION+" TEXT,"+
    COLUMN_DATE+" DATE,"+COLUMN_DONE+" BOOLEAN)";
    SQLiteDatabase db;

    public DatabaseHelper(Context context)
    {
        super(context,DATABASE_NAME,null,DATABASE_VERSION);
    }


    @Override
    public void onCreate(SQLiteDatabase db)
    {
        this.db = db;
        db.execSQL(CREATE_TABLE);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        String query = "DROP TABLE IF EXISTS "+TABLE_NAME;
        db.execSQL(query);
        this.onCreate(db);
    }

    public  void insertTask(Task task)
    {
        db = getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(COLUMN_DESCRIPTION,task.getDescription());
        values.put(COLUMN_DATE,task.getDate().toString());
        values.put(COLUMN_DONE,Boolean.FALSE.toString());
        db.insert(TABLE_NAME, null, values);
        db.close();
    }

    public ArrayList<Task> getAllTasks()
    {
        ArrayList<Task> items = new ArrayList<Task>();
        db = getReadableDatabase();
        String query = "SELECT * FROM "+TABLE_NAME;
        Cursor cursor = db.rawQuery(query,null);
        if(cursor.moveToFirst())
        {
            do{
                Task item = new Task();
                String date = cursor.getString(2);
                Date parsedDate = new Date();
                SimpleDateFormat format = new SimpleDateFormat("MM/dd/yyyy");
                try{
                    parsedDate = format.parse(date);
                }
                catch (ParseException e)
                {
                    parsedDate = null;
                }
                item.setId(cursor.getInt(0));
                item.setDescription(cursor.getString(1));
                item.setDate(parsedDate);
                item.setDone(Boolean.valueOf(cursor.getString(3)));
                items.add(item);
            }
            while (cursor.moveToNext());
        }
        return items;
    }

    public void markAsDone(int id){
        db = getWritableDatabase();
        ContentValues updatedData = new ContentValues();
        updatedData.put(COLUMN_DONE, Boolean.TRUE);
        String where = COLUMN_ID+" = "+String.valueOf(id);
        db.update(TABLE_NAME,updatedData,where,null);
    }
}

这是我在片段类中更新数据库的方法。我的片段类

    public class TaskListFragment extends Fragment {
        private DatabaseHelper dbHelper;
        private TextView taskTitle;
        private ListView taskListView;
        private ArrayAdapter adapter;
        @Nullable
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            dbHelper = new DatabaseHelper(getActivity());
            View view= inflater.inflate(R.layout.task_list, container, false);
            taskTitle = (TextView)view.findViewById(R.id.task_textview);
            taskListView = (ListView)view.findViewById(R.id.listViewTaskList);
            int type = getArguments().getInt("type");
            switch (type){
                case R.integer.task_list_all:
                    ArrayList<Task> items = dbHelper.getAllTasks();
                    adapter = new TaskListAdapter(getActivity(),items);
                    taskListView.setAdapter(adapter);
                    taskTitle.setText("All tasks");
                    break;
            }
            taskListView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
                @Override
                public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
                    int tagId = Integer.valueOf(view.getTag().toString());
                    showOptionDialog(tagId);
                    return true;
                }
            });
            return view;
        }

        public void showOptionDialog(final int id)
        {
            LayoutInflater layoutInflater = LayoutInflater.from(getActivity());
            View view = layoutInflater.inflate(R.layout.row_option_dialog, null);

            final AlertDialog alertDialog = new AlertDialog.Builder(getActivity()).create();
            Button doneBtn = (Button)view.findViewById(R.id.btn_row_option_done);
            doneBtn.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    dbHelper.markAsDone(id);
                    Toast.makeText(getActivity().getBaseContext(),"Marked as done",Toast.LENGTH_SHORT).show();
        //
        // This is showing toast message "Mark as done".
        // But data is not actually updated. Why is this?
        //
                }
            });
            Button editBtn = (Button)view.findViewById(R.id.btn_row_option_edit);
            editBtn.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                }
            });
            Button deleteBtn = (Button)view.findViewById(R.id.btn_row_option_delete);
            deleteBtn.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                }
            });
            Button cancelBtn = (Button)view.findViewById(R.id.btn_row_option_cancel);
            cancelBtn.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                }
            });
            alertDialog.setView(view);
            alertDialog.show();
        }
    }

我正在使用片段中的markAsDone方法更新行。我的代码出了什么问题？我不知道解决它，因为它没有抛出任何错误。

我只在logcat

中得到了这个

01-25 10:09:00.177 128-336/? W/genymotion_audio: out_write() limiting sleep time 26780 to 23219
01-25 10:09:02.509 128-336/? W/genymotion_audio: out_write() limiting sleep time 31155 to 23219
01-25 10:09:04.337 2622-2622/? I/dalvikvm: Could not find method android.content.res.Resources.getDrawable, referenced from method android.support.v7.widget.ResourcesWrapper.getDrawable
01-25 10:09:04.337 2622-2622/? W/dalvikvm: VFY: unable to resolve virtual method 399: Landroid/content/res/Resources;.getDrawable (ILandroid/content/res/Resources$Theme;)Landroid/graphics/drawable/Drawable;
01-25 10:09:04.341 2622-2622/? D/dalvikvm: VFY: replacing opcode 0x6e at 0x0002
01-25 10:09:04.341 2622-2622/? I/dalvikvm: Could not find method android.content.res.Resources.getDrawableForDensity, referenced from method android.support.v7.widget.ResourcesWrapper.getDrawableForDensity
01-25 10:09:04.341 2622-2622/? W/dalvikvm: VFY: unable to resolve virtual method 401: Landroid/content/res/Resources;.getDrawableForDensity (IILandroid/content/res/Resources$Theme;)Landroid/graphics/drawable/Drawable;
01-25 10:09:04.341 2622-2622/? D/dalvikvm: VFY: replacing opcode 0x6e at 0x0002
01-25 10:09:04.349 2622-2626/? D/dalvikvm: GC_CONCURRENT freed 1457K, 20% free 6388K/7980K, paused 1ms+1ms, total 7ms
01-25 10:09:08.705 128-336/? W/genymotion_audio: out_write() limiting sleep time 30339 to 23219
01-25 10:09:14.709 2622-2622/? W/EGL_genymotion: eglSurfaceAttrib not implemented
01-25 10:09:19.653 407-991/? W/InputMethodManagerService: Window already focused, ignoring focus gain of: com.android.internal.view.IInputMethodClient$Stub$Proxy@533e36b4 attribute=null, token = android.os.BinderProxy@53391868
01-25 10:09:21.509 2622-2622/? W/EGL_genymotion: eglSurfaceAttrib not implemented
01-25 10:09:22.957 128-336/? W/genymotion_audio: out_write() limiting sleep time 61269 to 23219
01-25 10:09:22.977 128-336/? W/genymotion_audio: out_write() limiting sleep time 52879 to 23219
01-25 10:09:23.005 128-336/? W/genymotion_audio: out_write() limiting sleep time 44489 to 23219
01-25 10:09:23.029 128-336/? W/genymotion_audio: out_write() limiting sleep time 36099 to 23219

当我记录update语句的返回值时，它返回1。

Answer 1

1）。检查Logcat您是否有任何错误。

2）。启用日志记录以查看您正在执行的所有SQL语句：

https://gist.github.com/davetrux/9741432

adb shell setprop log.tag.SQLiteLog V
adb shell setprop log.tag.SQLiteStatements V
adb shell stop
adb shell start

或者阅读：https://stackoverflow.com/a/19152852/1796309
或者：https://stackoverflow.com/a/6057886/1796309

无论如何，您需要检查您是否正在进行正确的SQL查询。

3）。如果您的查询状况良好，但仍无法更新行，则需要执行以下操作：

3.1）转到<android-sdk-dir>/platform-tools

3.2）。确保您当前的版本为Debug（不是Release，否则您会收到消息adbd cannot run as root in production builds）。

我的意思是你应该通过这个按钮运行你的应用程序：

然后运行下一个命令：

./adb root
./adb shell
run-as com.mycompany.app    //<----------- your applicationId from build.gradle
ls -l
drwxrwx--x u0_a88   u0_a88            2016-01-25 15:44 cache
drwx------ u0_a88   u0_a88            2016-01-25 15:25 code_cache
drwxrwx--x u0_a88   u0_a88            2016-01-25 15:44 databases    //<----
drwxrwx--x u0_a88   u0_a88            2016-01-25 15:26 files

cd databases/
ls -l
-rw-rw---- u0_a88   u0_a88     172032 2016-01-25 15:45 <your-app>.db
-rw------- u0_a88   u0_a88      33344 2016-01-25 15:45 <your-app>.db-journal

chmod 777 -R <your-app>.db
exit
exit
./adb pull /data/data/<your applicationId from build.gradle>/databases/<your-app>.db ~/projects/

在此之后，您将在~/projects/目录中获得SQLite数据库的副本。

使用例如：http://sqlitebrowser.org/

打开它

尝试执行更新查询，您可以从Logcat获取您将看到所有SQL错误，并且您将能够非常快速地修复它。

祝你好运！

Answer 2

sqlite中没有布尔数据类型而是使用Integer。

public void markAsDone(int id){
        db = getWritableDatabase();
        ContentValues updatedData = new ContentValues();
        updatedData.put(COLUMN_DONE, 1);
        String where = COLUMN_ID + "=?"
        db.update(TABLE_NAME,updatedData,where,new String[]{String.valueOf(id)});
    }

Answer 3

我得到了答案。现在我在DatabaseHelper中的markAsDone方法中更新数据库中行的布尔值。

updatedData.put(COLUMN_DONE, Boolean.TRUE);

然后我把它改成了

updatedData.put(COLUMN_DONE, String.valueOf(Boolean.TRUE));

我需要将boolean值解析为string。

无法在Android中更新Sqlite中的行但不会抛出任何错误

3 个答案: