Question

我有一个工作正常的数据库。现在我要将我的数据库文件添加到项目中。我在资产文件夹中有一个数据库文件。但是不知道如何在项目的任何主体中导入它来解决我的问题。

这是我的dbhelper类

public class FoodDbHelper extends SQLiteOpenHelper {
private static final String DATABASE_NAME = "pkfood_calories.DB";
private static final int DATABASE_VERSION = 1;
private static final String CREATE_QUERY =
        "CREATE TABLE "+ Food.NewDishInfo.TABLE_NAME+"("
                + Food.NewDishInfo.DISH_NAME+" TEXT NOT NULL,"
                + Food.NewDishInfo.DISH_QUANTITY+" TEXT NOT NULL,"
                + Food.NewDishInfo.DISH_CALORIE+" INTEGER,"
                + Food.NewDishInfo.DISH_FAT+" TEXT NOT NULL,"
                + Food.NewDishInfo.DISH_PROTEIN+" TEXT NOT NULL,"
                + Food.NewDishInfo.DISH_SUGAR+" TEXT NOT NULL,"
                + Food.NewDishInfo.DISH_VITAMINS+" TEXT NOT NULL);";
public FoodDbHelper(Context context)
{
    super(context,DATABASE_NAME,null,DATABASE_VERSION);
    Log.e("DATABASE OPERATION","Database created / opened...");
}
@Override
public void onCreate(SQLiteDatabase db) {
    db.execSQL(CREATE_QUERY);
    Log.e("DATABASE OPERATION","Table created...");


}
public void addInformations(String name ,String quantity, Integer calorie, String fat ,
                            String protein,String sugar,String vitamins, SQLiteDatabase db){


    ContentValues contentValues = new ContentValues();
    contentValues.put(Food.NewDishInfo.DISH_NAME,name);
    contentValues.put(Food.NewDishInfo.DISH_QUANTITY,quantity);
    contentValues.put(Food.NewDishInfo.DISH_CALORIE,calorie);
    contentValues.put(Food.NewDishInfo.DISH_FAT,fat);
    contentValues.put(Food.NewDishInfo.DISH_PROTEIN,protein);
    contentValues.put(Food.NewDishInfo.DISH_SUGAR,sugar);
    contentValues.put(Food.NewDishInfo.DISH_VITAMINS,vitamins);
    db.insert(Food.NewDishInfo.TABLE_NAME, null, contentValues);
    Log.e("DATABASE OPERATION","one row inserted...");
}
public Cursor getInformations(SQLiteDatabase db){
    Cursor cursor;
    String[] projections = {Food.NewDishInfo.DISH_NAME,Food.NewDishInfo.DISH_QUANTITY,
            Food.NewDishInfo.DISH_CALORIE,Food.NewDishInfo.DISH_FAT,Food.NewDishInfo.DISH_PROTEIN,
            Food.NewDishInfo.DISH_SUGAR, Food.NewDishInfo.DISH_VITAMINS};
    cursor= db.query(Food.NewDishInfo.TABLE_NAME,projections,null,null,null,null,"DISH_NAME ASC");
    return cursor;
}

Answer 1

假设您的数据库文件名为＆＃34; a.db＆＃34;，您可以这样做：

try {
        File file = new File(dbfile); //dbfile is a file path that you save the database
        if (!file.exists()) {
            Log.e("cc", "file");
            InputStream is = Context.getAssets().open("school.db");
            FileOutputStream fos = new FileOutputStream(dbfile);
            byte[] buffer = new byte[1024];
            int count = 0;
            while ((count = is.read(buffer)) > 0) {
                fos.write(buffer, 0, count);
                fos.flush();
            }
            fos.close();
            is.close();
        }
        SQLiteDatabase database = SQLiteDatabase.openOrCreateDatabase(dbfile, null);
    } catch (FileNotFoundException e) {
        Log.e("cc", "File not found");
        e.printStackTrace();
    } catch (IOException e) {
        Log.e("cc", "IO exception");
        e.printStackTrace();
    } catch (Exception e) {
        Log.e("cc", "exception " + e.toString());
    }

Android如何在项目中导入数据库文件

1 个答案: