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当我尝试使用删除方法删除数据库中的一行时，我的 android 代码出现问题。但是，我不想使用 ID，而是使用我创建的字符串的名称。重点是用户在编辑文本中输入名称并删除字符串行。我对此很陌生，希望您能提供意见！我会带你看我的代码...

这是我的数据

public class Key_Manager extends SQLiteOpenHelper {

    private static final int DATABASE_VERSION = 1;
    private static final String CREATE_KEYS_TABLE = "CREATE TABLE " + KeyEntry.TABLE_NAME +
            " (" +
            KeyEntry.KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT," +
            KeyEntry.COLUMN_NAME_NAME + " TEXT," +
            KeyEntry.COLUMN_NAME_KEY + " TEXT" + ")";

    public Key_Manager(Context context)
    {
        super(context,KeyEntry.DB_NAME, null, DATABASE_VERSION );
    }
    @Override
    public void onCreate(SQLiteDatabase db)
    {
        db.execSQL(CREATE_KEYS_TABLE);
    }
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
    {
        db.execSQL("DROP TABLE IF EXISTS" + KeyEntry.TABLE_NAME);
        onCreate(db);

    }


    public void addKey(String name, String key)
    {
        SQLiteDatabase db = this.getWritableDatabase();

        ContentValues values = new ContentValues();
        values.put(KeyEntry.COLUMN_NAME_NAME, name);
        values.put(KeyEntry.COLUMN_NAME_KEY, key);
        try{db.insertOrThrow(KeyEntry.TABLE_NAME, null, values);}
        catch(Exception e)
        {
            Log.e("Error in inserting rows", e.toString());
            e.printStackTrace();

        }
        db.close();
    }

    public ArrayList<String> getKeys(int id)
    {
        ArrayList<String> listRows = new ArrayList<String>();
        SQLiteDatabase db = this.getReadableDatabase();
        String[] keys = new String[]
                {
                        KeyEntry.KEY_ID, KeyEntry.COLUMN_NAME_NAME,
                        KeyEntry.COLUMN_NAME_KEY };
        Cursor cursor = db.query(KeyEntry.TABLE_KEY, keys, KeyEntry.KEY_ID + "=?", null, null, null, null);
        if(cursor !=null)
        {
            cursor.moveToFirst();
        }
        while(cursor.isAfterLast()==false)
        {
            listRows.add(cursor.getString(0));
            listRows.add(cursor.getString(1));
            cursor.moveToNext();
        }
        if(cursor != null && !cursor.isClosed())
        {
            cursor.close();
        }
        return listRows;
    }

    public void onDownGrade(SQLiteDatabase db, int oldVersion, int newVersion)
    {
        onUpgrade(db, oldVersion, newVersion);
    }

    public void deleteKey(String name) //THIS IS WHERE I AM HAVING PROBLEMS, WHAT SHOULD I DO HERE?
    {
        SQLiteDatabase db = this.getWritableDatabase();
        db.delete(KeyEntry.TABLE_NAME, KeyEntry.COLUMN_NAME_NAME,new String[]{name});

    }

}

这是我要删除它的地方

public class Delete_Keys extends Activity {

    private Key_Manager keyManager; 
    EditText delete; 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_delete__keys);
        delete = (EditText) findViewById(R.id.enterDelete);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.delete__keys, menu);
        return true;
    }



    public void deleteButton(View v)//AM I DOING THIS CORRECT? WHAT CAN I DO BETTER?
    {
        String name = delete.getText().toString();
        keyManager = new Key_Manager(this);
        keyManager.deleteKey(name);
    }
}
4

1 回答 1

1

这对我有用：

public void deleteKey(String name)
{
    SQLiteDatabase db = this.getWritableDatabase();
    db.delete(KeyEntry.TABLE_NAME, KeyEntry.COLUMN_NAME_NAME + "=" + name, null);
}
于 2013-11-12T21:50:31.750 回答