在vs中使用oledb连接dbf文件，使用oledb的Transaction物件，执行rollback时却无法回滚，请问是什么原因？
代码如下：
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                OleDbConnection connection=new OleDbConnection(@"provider=vfpoledb;data source=xxxxxx")
                connection.Open();
                using (OleDbTransaction tran = connection.BeginTransaction())
                {
                    OleDbCommand cmd = new OleDbCommand("Insert Into TestTable(mremark) values('XXXX')", connection);
                    cmd.Transaction = tran;
                    int result = cmd.ExecuteNonQuery();
                    int a = 0;
                    int b = 1 / a;
                    ();
                }
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代码中在事务Commit前故意出错，却发现没回滚。