android本地資料庫，微信資料庫WCDB for Android 使用例項

WCDB是一個高效、完整、易用的移動資料庫框架，基於SQLCipher，支援iOS, macOS和Android。
編譯依賴項不是必要的，你完全可以使用預先編譯好的庫。
build.gradle 引入：
dependencies {
implementation 'com.tencent.wcdb:wcdb-android:1.0.2'
}

WCDB for Android
基本功能
基於SQLCipher的資料庫加密
使用連線池實現併發讀寫
內建 Repair Kit 可用於修復損壞資料庫
針對佔用空間大小優化的資料庫備份/恢復功能
日誌輸出重定向以及效能跟蹤介面
內建用於全文搜尋的 mmicu FTS3/4 分詞器

例項：

import android.content.Context;

import com.tencent.wcdb.DatabaseErrorHandler;
import com.tencent.wcdb.database.SQLiteDatabase;
import com.tencent.wcdb.database.SQLiteOpenHelper;

import java.io.File;

class WcdbHelper extends SQLiteOpenHelper {
    private Context mContext;

    
 
public WcdbHelper(Context context, String name, byte[] password, SQLiteDatabase.CursorFactory factory, int version, DatabaseErrorHandler errorHandler) {
        super(context, name, password, factory, version, errorHandler);
        this.mContext = context;
    }

    @Override
    public void
 
 onCreate(SQLiteDatabase db) {

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        LogUtil.i("db","oldVersion:" + oldVersion);
        LogUtil.i("db","newVersion:" + newVersion);
    }

    public boolean onDelete(String name) {
        File file = mContext.getDatabasePath(name);
        return SQLiteDatabase.deleteDatabase(file);
    }
}

import android.content.ContentValues;
import android.content.Context;

import com.aax.exchange.entity.Favorites;
import com.tencent.wcdb.Cursor;
import com.tencent.wcdb.database.SQLiteDatabase;

import java.util.ArrayList;
import java.util.List;

public class FavoritesDBManager {
    private WcdbHelper mDBHelper;
    private SQLiteDatabase mDB;
    private String name = "favorites.db";
    private String password = "xxx";

    public FavoritesDBManager(Context context) {
        mDBHelper = new WcdbHelper(context,name,password.getBytes(),null,1,null);
        mDB = mDBHelper.getWritableDatabase();
        addTable();
    }

    public boolean addFavoritesData(String tradingPair) {
        try {
            mDB.beginTransaction();

            final String sql = "INSERT INTO favorites VALUES(NULL,?)";
            Object[] objects = new Object[]{tradingPair};
            mDB.execSQL(sql, objects);

            mDB.setTransactionSuccessful();
        }catch (Exception e){
            return false;
        }finally {
            mDB.endTransaction();
        }
        return true;
    }

    public boolean addFavoritesData(Favorites favorites) {
        try {
            mDB.beginTransaction();

            final String sql = "INSERT INTO favorites VALUES(NULL,?)";
            Object[] objects = new Object[]{favorites.getTradingPair()};
            mDB.execSQL(sql, objects);

            mDB.setTransactionSuccessful();
        }catch (Exception e){
            return false;
        }finally {
            mDB.endTransaction();
        }
        return true;
    }

    public boolean addFavoritesList(List<Favorites> list) {
        try {
            mDB.beginTransaction();

            for (Favorites favorites : list) {
                Object[] objects = new Object[]{favorites.getTradingPair()};
                final String sql = "INSERT INTO favorites VALUES(NULL,?)";
                mDB.execSQL(sql, objects);
            }

            mDB.setTransactionSuccessful();
        } catch (Exception e) {
            return false;
        } finally {
            mDB.endTransaction();
        }
        return true;
    }

    public boolean delFavoritesByTradingPair(String tradingPair) {
        try {
            mDB.beginTransaction();
            mDB.delete("favorites","tradingPair=?",new String[]{tradingPair});
            mDB.setTransactionSuccessful();
        } catch (Exception e) {
            return false;
        } finally {
            mDB.endTransaction();
        }
        return true;
    }

    public Favorites getFavoritesByTradingPair(String tradingPair){
        String sql = "select * from favorites where tradingPair=?";
        Cursor cursor = mDB.rawQuery(sql, new String[]{tradingPair});
        while (cursor.moveToNext()){
            Favorites favorites = new Favorites();
            favorites.setTradingPair(cursor.getString(cursor.getColumnIndex("tradingPair")));
            return favorites;
        }
        return null;
    }

    public List<Favorites> getFavoritesListData() {
        List<Favorites> listData = new ArrayList<>();
        Cursor c = getAllFavoritesInfo();
        while (c.moveToNext()) {
            Favorites favorites = new Favorites();
            favorites.setTradingPair(c.getString(c.getColumnIndex("tradingPair")));
            listData.add(favorites);
        }
        c.close();
        return listData;
    }

    private Cursor getAllFavoritesInfo() {
        return mDB.rawQuery("SELECT * FROM favorites", null);
    }

    public boolean updateFavoritesByName(String tradingPair){
        ContentValues values = new ContentValues();
        values.put("tradingPair", tradingPair);
        int flag = mDB.update("favorites", values, "tradingPair=?", new String[]{tradingPair});
        if (flag > 0) {
            return true;
        } else {
            return false;
        }
    }

    public void closeDB() {
        mDB.close();
    }

    public Boolean deleteDatabase(String name) {
        return mDBHelper.onDelete(name);
    }

    public void deleteFavoritesData() {
        mDB.execSQL("DELETE FROM favorites;");
    }
    public void addTable() {
        String SQL_CREATE = "CREATE TABLE IF NOT EXISTS favorites (_id INTEGER PRIMARY KEY AUTOINCREMENT , tradingPair VARCHAR(50) )";
        mDB.execSQL(SQL_CREATE);
    }

}

public class Favorites {
    private String tradingPair;

    public String getTradingPair() {
        return tradingPair;
    }

    public void setTradingPair(String tradingPair) {
        this.tradingPair = tradingPair;
    }
}

public void addFavorites(CoinListInfo data,BaseBindingAdapter mAdapter,Context context){
       LogUtil.i("wxh", "getQuote=" + data.getQuote() + " getBase=" + data.getBase());

        subscribe(coinSearchActivity,Api.getApiService().addFavorites(data.getQuote() + data.getBase()),
                new ObserverResponseListener<Object>() {
            @Override
            public void onNext(Object o) {
                //ToastUtil.showLongToast("add favorites on next");
                String tradingPair = data.getQuote() + data.getBase();
                FavoritesDBManager fm = new FavoritesDBManager(context);
                Favorites fav = new Favorites();
                fav.setTradingPair(tradingPair);
                //if exits set true or set false
                if(data.isFavorite.get()){
                    data.isFavorite.set(Boolean.FALSE);
                    fm.delFavoritesByTradingPair(tradingPair);
                }else{
                    data.isFavorite.set(Boolean.TRUE);
                    fm.addFavoritesData(fav);
                }

                mAdapter.notifyDataSetChanged();
            }

            @Override
            public void onError(Throwable e) {
                ToastUtil.showLongToast("add favorites error");
            }
        }, coinSearchActivity.bindToLifecycle());

   }

private void setSearch() {
        mCompositeDisposable.add(RxTextView.textChanges(mBinding.etSearchKey)
                    .debounce(300, TimeUnit.MILLISECONDS)
                    .observeOn(AndroidSchedulers.mainThread())
                    .map(CharSequence::toString)
                    .subscribe(s -> {
                        //這裡可以查詢資料庫或請求伺服器查詢
                        if (!TextUtils.isEmpty(s.trim())){
                            searchList.clear();
                            FavoritesDBManager fm = new FavoritesDBManager(CoinSearchActivity.this);
                            for (CoinListInfo item:
                                    mCoinSearchViewModel.data) {
                                if (item.getQuote().contains(s.toUpperCase()) || item.getBase().contains(s.toUpperCase())){
                                    String tradingPair = item.getQuote() + item.getBase();
                                    Favorites fav = fm.getFavoritesByTradingPair(tradingPair);
                                    if(null != fav){
                                        item.isFavorite.set(Boolean.TRUE);
                                    }
                                    searchList.add(item);
                                }
                            }

                            mAdapter.setFilterData(searchList);

                        }else{
                            mAdapter.setFilterData(null);
                        }

                    }));


    }