如何从sqlite数据库的表中删除用户信息？

我试图删除用户当管理员输入用户名，然后单击删除按钮，它将删除数据库中的所有用户信息（用户名，密码，用户号码，地址，电话）我对此非常陌生，所以我可能做了一些完全错误的事，但当我尝试这样做时，应用程序会注销。我的代码中没有错误，所以我对自己做错了什么感到困惑。任何关于做什么的帮助或指导都会对我帮助很大，我非常感激

DatabaseHelperUser类：

public class DatabaseHelperUser extends SQLiteOpenHelper {

public static final String DATABASE_NAME = "User.db";
public static final String TABLE_NAME = "User_table";
public static final String COL1 = "UserNum";
public static final String COL2 = "UserName";
public static final String COL3 = "Password";
public static final String COL4 = "BirthDate";
public static final String COL5 = "Phone";
public static final String COL6 = "Address";


public DatabaseHelperUser(Context context) {
    super(context, DATABASE_NAME, null, 1);
}


@Override
public void onCreate(SQLiteDatabase db) {

    db.execSQL("create table " + TABLE_NAME + " (ID INTEGER PRIMARY KEY AUTOINCREMENT, UserNum TEXT,UserName Text,Password Text,BirthDate Text,Phone Text,Address Text)");

}

@Override
public void onUpgrade(SQLiteDatabase db, int i, int i1) {

    db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
    onCreate(db);
}

public Cursor getData() {
    SQLiteDatabase db = this.getWritableDatabase();
    Cursor res = db.rawQuery("select * from " + TABLE_NAME, null);
    return res;
}

public Integer deleteData(String UserName) {
    SQLiteDatabase db = this.getWritableDatabase();
    return db.delete(TABLE_NAME, "UserName = ?", new String[]{UserName});



}

}

RemoveUser类： 公共类RemoveUser扩展AppCompatActivity{

Button btdelete;
EditText txtUser;

DatabaseHelperUser myDb;

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

    btdelete = (Button) findViewById(R.id.buttonRemove1);
    txtUser = (EditText) findViewById(R.id.etxtUserName);

    myDb = new DatabaseHelperUser(this);

    DeleteData();

}
public void DeleteData(){
    btdelete.setOnClickListener(new View.OnClickListener() {

        public void onClick(View view) {
            Integer deleteRows = myDb.deleteData(txtUser.getText().toString());
            if(deleteRows > 0 )
                Toast.makeText(RemoveUser.this, "Data Deleted", Toast.LENGTH_LONG).show();
            else
                Toast.makeText(RemoveUser.this, "Data has not been Deleted", Toast.LENGTH_LONG).show();

        }
    });
}
}