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