学步园

package com.njupt.sqllist;

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

import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;

public class PersonDao {

	DBOpenHelper helper;

	public PersonDao(Context context) {
		helper = new DBOpenHelper(context);
	}

	
	public void remit(int from, int to, int count) {
		SQLiteDatabase db = helper.getWritableDatabase();
		try {
			db.beginTransaction();

			db.execSQL("update person set balance = balance - ? where id = ?",
					new Object[] { count, from });
			System.out.println(1 / 0);
			db.execSQL("update person set balance = balance + ? where id = ?",
					new Object[] { count, to });

			db.setTransactionSuccessful();
		} finally {

			db.endTransaction();
			db.close();
		}
	}

	
}

2、解释：

1)db.beginTransaction();开启事务

2)db.setTransactionSuccessful();//设置成功点

3)db.endTransaction();//结束事务。将成功点以前的事务提交