ORA-12514:C#连接Oracle数据库出错

    如题，在连接甲骨文数据库的时候出现了问题，显示无法识别该连接符，连接代码如下：

            string ConnectionString;
            string QueryString;

            ConnectionString = "Data Source = 127.0.0.1/lin;User ID=linxl;PassWord=linxl";
            QueryString = String.Format("select * from tblcarton2rcard where CARTONNO='{0}'", CARTONNO);
            OracleConnection MyConnection = new OracleConnection(ConnectionString);
            OracleCommand MyCommand = MyConnection.CreateCommand();

            MyCommand.CommandText = QueryString;
            MyConnection.Open();

然后就弹出了这个错误框

奇怪的是，用同样连接方法，在一些程序中却可以正常运行，没有报错。

后来去查了一些资料，改成下面这种形式的字符串就可以正常进行连接了

            string ConnectionString;
            string QueryString;

            ConnectionString = "Data Source = (DESCRIPTION =(ADDRESS_LIST =(ADDRESS = (PROTOCOL = TCP)(HOST = 127.0.0.1)(PORT = 1521)))(CONNECT_DATA =(SERVICE_NAME = lin)));User ID=linxl;PassWord=linxl";

            QueryString = String.Format("select * from tblcarton2rcard where CARTONNO='{0}'", CARTONNO);
            OracleConnection MyConnection = new OracleConnection(ConnectionString);
            OracleCommand MyCommand = MyConnection.CreateCommand();

            MyCommand.CommandText = QueryString;

            MyConnection.Open();

连接上了后就可以进行数据库的操作了