java - Android 数据库更新不起作用

Question

这是我的数据库助手:

public class PersonDatabaseHelper {

private static final String TAG = PersonDatabaseHelper.class.getSimpleName();

// database configuration
// if you want the onUpgrade to run then change the database_version
private static final int DATABASE_VERSION = 7;
private static final String DATABASE_NAME = "database.db";

// table configuration
 static final String TABLE_NAME = "person_table";         // Table name
 static final String PERSON_TABLE_COLUMN_ID = "_id";     // a column named "_id" is required for cursor
 static final String PERSON_TABLE_COLUMN_NAME = "person_name";
 static final String PERSON_TABLE_COLUMN_SURNAME = "person_surname";
 static final String PERSON_TABLE_COLUMN_ENTERDATE = "person_enterdate";
 static final String PERSON_TABLE_COLUMN_ENTERTIME = "person_entertime";
 static final String PERSON_TABLE_COLUMN_EXITDATE = "person_exitdate";
 static final String PERSON_TABLE_COLUMN_EXITTIME = "person_exittime";

private DatabaseOpenHelper openHelper;
private SQLiteDatabase database;

// this is a wrapper class. that means, from outside world, anyone will communicate with PersonDatabaseHelper,
// but under the hood actually DatabaseOpenHelper class will perform database CRUD operations 
public PersonDatabaseHelper(Context aContext) {

    openHelper = new DatabaseOpenHelper(aContext);
    database = openHelper.getWritableDatabase();
}

public void insertData (String aPersonName, String aPersonSurName, String aPersonEnterDate,String aPersonEnterTime, String aPersonExitDate,String aPersonExitTime) {

    // we are using ContentValues to avoid sql format errors

    ContentValues contentValues = new ContentValues();

    contentValues.put(PERSON_TABLE_COLUMN_NAME, aPersonName);
    contentValues.put(PERSON_TABLE_COLUMN_SURNAME, aPersonSurName);
    contentValues.put(PERSON_TABLE_COLUMN_ENTERDATE, aPersonEnterDate);
    contentValues.put(PERSON_TABLE_COLUMN_ENTERTIME, aPersonEnterTime);
    contentValues.put(PERSON_TABLE_COLUMN_EXITDATE, aPersonExitDate);
    contentValues.put(PERSON_TABLE_COLUMN_EXITTIME, aPersonExitTime);

    database.insert(TABLE_NAME, null, contentValues);

}

      public void update_byID(int id, String name, String surname, String enterDate, String enterTime,String exitDate,String exitTime){
      ContentValues values = new ContentValues();
      values.put(PERSON_TABLE_COLUMN_NAME, name);
      values.put(PERSON_TABLE_COLUMN_SURNAME, surname);
      values.put(PERSON_TABLE_COLUMN_ENTERDATE, enterDate);
      values.put(PERSON_TABLE_COLUMN_ENTERTIME, enterTime);
      values.put(PERSON_TABLE_COLUMN_EXITDATE, exitDate);
      values.put(PERSON_TABLE_COLUMN_EXITTIME, exitTime);
      database.update(TABLE_NAME, values, PERSON_TABLE_COLUMN_ID+"="+id, null);
     }


    public Cursor getAllData () {

    String buildSQL = "SELECT * FROM " + TABLE_NAME;

    Log.d(TAG, "getAllData SQL: " + buildSQL);

    return database.rawQuery(buildSQL, null);
}


// this DatabaseOpenHelper class will actually be used to perform database related operation 

private class DatabaseOpenHelper extends SQLiteOpenHelper {

       public DatabaseOpenHelper(Context aContext) {
        super(aContext, DATABASE_NAME, null, DATABASE_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase sqLiteDatabase) {
        // Create your tables here

        String buildSQL = "CREATE TABLE " + TABLE_NAME + "( " + PERSON_TABLE_COLUMN_ID + " INTEGER PRIMARY KEY, " +
                PERSON_TABLE_COLUMN_NAME + " TEXT, " + PERSON_TABLE_COLUMN_SURNAME + " TEXT, " + PERSON_TABLE_COLUMN_ENTERDATE + " TEXT," + PERSON_TABLE_COLUMN_ENTERTIME + " TEXT," + PERSON_TABLE_COLUMN_EXITDATE + " TEXT," + PERSON_TABLE_COLUMN_EXITTIME + " TEXT )";

        Log.d(TAG, "onCreate SQL: " + buildSQL);

        sqLiteDatabase.execSQL(buildSQL);
    }

    @Override
    public void onUpgrade(SQLiteDatabase sqLiteDatabase, int oldVersion, int newVersion) {
        // Database schema upgrade code goes here

        String buildSQL = "DROP TABLE IF EXISTS " + TABLE_NAME;

        Log.d(TAG, "onUpgrade SQL: " + buildSQL);

        sqLiteDatabase.execSQL(buildSQL);       // drop previous table

        onCreate(sqLiteDatabase);               // create the table from the beginning
    }
     }

我的列表类:

 public class List extends ActionBarActivity{

private CustomCursorAdapter customAdapter;
private PersonDatabaseHelper databaseHelper;
private static final int ENTER_DATA_REQUEST_CODE = 1;
private ListView listView;

private static final String TAG = List.class.getSimpleName();

/**
 * Called when the activity is first created.
 */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.listview);

    databaseHelper = new PersonDatabaseHelper(this);

    listView = (ListView) findViewById(R.id.list_data);
    listView.setOnItemClickListener(new OnItemClickListener() {



        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            Log.d(TAG, "clicked on item: " + position);



                Intent intent = new Intent(List.this, Edit.class);
                Person p = new Person();
                Cursor cursor = (Cursor) customAdapter.getItem(position);
                p.name = cursor.getString(cursor.getColumnIndex("person_name"));
                p.surname = cursor.getString(cursor.getColumnIndex("person_surname"));
                p.enterDate = cursor.getString(cursor.getColumnIndex("person_enterdate"));
                p.enterTime = cursor.getString(cursor.getColumnIndex("person_entertime"));
                p.exitDate = cursor.getString(cursor.getColumnIndex("person_exitdate"));
                p.exitTime = cursor.getString(cursor.getColumnIndex("person_exittime"));


                intent.putExtra("update_id", position);                               
                intent.putExtra("name",p.name);
                intent.putExtra("surname",p.surname );
                intent.putExtra("enterdate",p.enterDate );
                intent.putExtra("entertime",p.enterTime);
                intent.putExtra("exitdate", p.exitDate);
                intent.putExtra("exittime", p.exitTime);

                startActivity(intent);

        }
    });
    listView.setOnLongClickListener(new OnLongClickListener() {


        @Override
        public boolean onLongClick(View v) {
            return false;
            // TODO Auto-generated method stub


        }
    }); 
    // Database query can be a time consuming task ..
    // so its safe to call database query in another thread
    // Handler, will handle this stuff for you <img src="http://s0.wp.com/wp-includes/images/smilies/icon_smile.gif?m=1129645325g" alt=":)" class="wp-smiley">

    new Handler().post(new Runnable() {
        @Override
        public void run() {
            customAdapter = new CustomCursorAdapter(List.this, databaseHelper.getAllData());
            listView.setAdapter(customAdapter);
        }
    });
}

     public void onClickEnterData(View btnAdd) {

      startActivityForResult(new Intent(this, Permission.class), ENTER_DATA_REQUEST_CODE);

}

    public void onClickLogOut(View btnLogOut){
   Intent intent = new Intent(List.this,
           MainActivity.class);
   intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
   startActivity(intent);
    }

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {

    super.onActivityResult(requestCode, resultCode, data);

    if (resultCode == RESULT_OK) {

        databaseHelper.insertData(data.getExtras().getString("tag_person_name"), data.getExtras().getString("tag_person_surname"),data.getExtras().getString("tag_person_enterdate"),data.getExtras().getString("tag_person_entertime"),data.getExtras().getString("tag_person_exitdate"),data.getExtras().getString("tag_person_exittime"));

        customAdapter.changeCursor(databaseHelper.getAllData());
    }
    if(resultCode == RESULT_FIRST_USER){
         databaseHelper.update_byID(data.getExtras().getInt("update_id"),data.getExtras().getString("update_person_name"), data.getExtras().getString("update_person_surname"),data.getExtras().getString("update_person_enterdate"),data.getExtras().getString("update_person_entertime"),data.getExtras().getString("update_person_exitdate"),data.getExtras().getString("update_person_exittime"));

         customAdapter.changeCursor(databaseHelper.getAllData());
    }
     }

我的 Edit 类，其中处理更新按钮是由 onClickSave 定义的:

 public class Edit extends ActionBarActivity {

EditText name;
EditText surName;
EditText date;
EditText time;
EditText eDate;
EditText eTime;

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


    Intent intent = getIntent();
     String data_name = intent.getStringExtra("name");
     String data_surname = intent.getStringExtra("surname");
     String data_enterdate= intent.getStringExtra("enterdate");
     String data_entertime = intent.getStringExtra("entertime");
     String data_exitdate = intent.getStringExtra("exitdate");
     String data_exittime = intent.getStringExtra("exittime"); //typo here


     name = (EditText) findViewById(R.id.username); //corrected
     surName = (EditText) findViewById(R.id.usersurname); //corrected
     date = (EditText) findViewById(R.id.date2);
     time = (EditText) findViewById(R.id.time2);
     eDate = (EditText) findViewById(R.id.date3);
     eTime = (EditText) findViewById(R.id.time3);

     name.setText(data_name);
     surName.setText(data_surname);
     date.setText(data_enterdate);
     time.setText(data_entertime);
     eDate.setText(data_exitdate);
     eTime.setText(data_exittime);
}

public void onCancel(View btnCancel){
finish();
 }
 public void onClickSave(View btnSave){
        String personName = name.getText().toString();
        String personSurName = surName.getText().toString();
        String personEnterDate = date.getText().toString();
        String personEnterTime = time.getText().toString();
        String personExitDate = eDate.getText().toString();
        String personExitTime = eTime.getText().toString();
        if ( personName.length() != 0 && personSurName.length() != 0&& personEnterDate.length() != 0&& personEnterTime.length() != 0&& personExitDate.length() != 0&& personExitTime.length() != 0 ) {

            Intent newIntent = getIntent();
            newIntent.putExtra("update_person_name", personName);
            newIntent.putExtra("update_person_surname", personSurName);
            newIntent.putExtra("update_person_enterdate", personEnterDate);
            newIntent.putExtra("update_person_entertime", personEnterTime);
            newIntent.putExtra("update_person_exitdate", personExitDate);
            newIntent.putExtra("updateperson_exittime", personExitTime);

            this.setResult(RESULT_FIRST_USER, newIntent);

            finish();
        }else {
            AlertDialog alertDialog = new AlertDialog.Builder(Edit.this).create();
            alertDialog.setTitle("Alert");
            alertDialog.setMessage("Fill all columns");
            alertDialog.setButton(AlertDialog.BUTTON_NEUTRAL, "OK",
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.dismiss();
                    }
                });
            alertDialog.show();
        }
 }
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.edit, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}
  }

所以问题是我试图通过调用编辑信息的编辑类来更新我在列表中选择的项目，然后通过单击单击保存它更新数据库，我已经编写了所有方法，但我不明白有什么问题，因为它不更新并且什么都不做。即使 logcat 也没有显示任何错误迹象。 :( 请有人帮助我:(

现在我尝试做的是将字符串发送到代码为 RESULT_FIRST_USER 的列表 Activity ，并在 protected void onActivityResult(int requestCode, int resultCode, Intent data) 上的列表 Activity 中，从数据库调用更新方法。

也是我的 Person 类:

public class Person {
int id;
String name;
String surname;
String enterDate;
String enterTime;
String exitDate;
String exitTime;
}

Answer 1

在您的 List Activity 中，当用户单击列表项并且您将项目数据发送到 Edit Activity (而不是 startActivity()，您必须调用startActivityForResult() 。然后，当您存储编辑的数据并在 Edit Activity 的 onClickSave() 中调用 setResult() 时，数据将传递到List Activity 的 onActivityResult() 方法..