Android - Green Dao Multiple Transaction

问题

I have some problem for multiple transaction in greendao example i already have two table with name book and type_book.

i already have code like this :

    SQLiteDatabase db = bookMasterDao.getDatabase();
    db.beginTransaction();

    try {
        bookMasterDao.insert(bookMaster);
        idBook = bookMaster.getId().intValue();
        db.setTransactionSuccessful();
    } catch (Exception ex) {
        System.out.println("Error insert book master " + ex);
    } finally {
        db.endTransaction();
    }



    SQLiteDatabase dbTypeBook = typeBookMasterDao.getDatabase();
    dbTypeBook.beginTransaction();

    try {
        typeBookMasterDao.insert(bookMaster);
        dbTypeBook.setTransactionSuccessful();
    } catch (Exception ex) {
        System.out.println("Error insert type book" + ex);
    } finally {
        dbTypeBook.endTransaction();
    }

I want if transaction type book failure insert , transaction book master rollback i mean cancel insert data book master. How to make transaction like that?

any idea, reference and example very help thank you.

回答1:

I think you misunderstood the principe. Try create db, start transaction, wrap the databse with daoMaster, use session for inserting, then set transaction successfull. Look at the code.

SQLiteDatabase db = openOrCreateDatabase("db", MODE_PRIVATE, null);
DaoMaster.createAllTables(db, true);

 db.beginTransaction();
 try {

  DaoMaster daoMaster = new DaoMaster(db);
  DaoSession daoSession = daoMaster.newSession();

  Book book = new Book();
  Book2 book2 = new Book2();

  //insert on specific session
  daoSession.getBookDao().insert(book);

  //set some relation to inserted book
  book2.setBook(book);

  //if this fails, book and book2 won't be in db
  //insert withou specific session
  daoSession.insert(book2); 

  db.setTransactionSuccessful();
} catch (Exception ex) {
    ex.printStackTrace();
} finally {
    db.endTransaction();
    db.close();
}

来源：https://stackoverflow.com/questions/32412573/android-green-dao-multiple-transaction

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java

android

sqlite

greendao