Question

我是Real编程的初学者。之前我使用过Sqlite，现在我尝试学习Realm.I找到了一个教程，一切都很完美

https://docs.oracle.com/cd/B19306_01/server.102/b14223/aggreg.htm

我可以在RecyclerView中显示我的所有值。但我有一个问题。如何从数据库中返回所有值，其中title等于例如hello并得到我可以在RecyclerView中显示它这是java代码

@Bind(R.id.edit_title) EditText mEditTitle;
@Bind(R.id.recycler_view)
RecyclerView mRecyclerView;
private Realm mRealm;

@Override
public void onCreate(final Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    mRealm = Realm.getInstance(getContext());
}

@Nullable
@Override
public View onCreateView(final LayoutInflater inflater, final ViewGroup container, final Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_edition, container, false);
    ButterKnife.bind(this, view);
    return view;
}


@Override
public void onViewCreated(final View view, @Nullable final Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    mRecyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
    mRealm.beginTransaction();
    RealmResults<MyBook> books = mRealm.where(MyBook.class).equalTo("title", "Hello").findAll();

    mRealm.commitTransaction();
    mRecyclerView.setAdapter(new MyListAdapter(mRealm.allObjects(MyBook.class)));
}

@Override
public void onDestroy() {
    super.onDestroy();
    mRealm.close();
}

@OnClick(R.id.button_add)
public void onAddClick() {
    mRealm.beginTransaction();
    MyBook book = mRealm.createObject(MyBook.class);
    book.setTitle(getTrimmedTitle());
    mRealm.commitTransaction();
}

@OnClick(R.id.button_remove)
public void onRemoveClick() {
    mRealm.beginTransaction();
    RealmResults<MyBook> books = mRealm.where(MyBook.class).equalTo("title", getTrimmedTitle()).findAll();
    if(!books.isEmpty()) {
        for(int i = books.size() - 1; i >= 0; i--) {
            books.get(i).removeFromRealm();
        }
    }
    mRealm.commitTransaction();
}

private String getTrimmedTitle() {
    return mEditTitle.getText().toString().trim();
}

如果有人知道解决方案，请帮助我。 P.s我说我是初学者Realm编程和好的教程或例子对我来说是完美的谢谢大家

Answer 1

Realm与任何其他数据库一样，进行查询。这适用于Iterator，但您可以拥有List

 Realm realm = Realm.getDefaultInstance();
 Iterator all = (MyBook)realm.where(MyBook.class).equalTo("title", "hello").findAll().iterator ();

其中title是MyBook类中变量的名称，hello是您要查找的名称

从Realm中的标题表中选择

1 个答案: