//......上面读取数据代码省略
        string ConStr = "server=(local);user id=sa;pwd=;database=forcastserver";
        SqlConnection conn = new SqlConnection(ConStr);
        conn.Open();//执行到这里就出错 ，提示“未处理 sqlexception ，用户sa登录失败”

       string SqlIns;
       qlIns = "insert into tb_hourdata values('"+SID [i]+"','"+Ri_Shi [i]+"',)";//字段添加列表
       conn.Close();

未处理 System.Data.SqlClient.SqlException
  Message="用户 'sa' 登录失败。"
  Source=".Net SqlClient Data Provider"
  ErrorCode=-2146232060
  Class=14
  LineNumber=65536
  Number=18456
  Procedure=""
  Server="(local)"
  State=1
  StackTrace:
       在 System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection)
       在 System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj)
       在 System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)
       在 System.Data.SqlClient.SqlInternalConnectionTds.CompleteLogin(Boolean enlistOK)
       在 System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, Boolean ignoreSniOpenTimeout, Int64 timerExpire, SqlConnection owningObject)
       在 System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(String host, String newPassword, Boolean redirectedUserInstance, SqlConnection owningObject, SqlConnectionString connectionOptions, Int64 timerStart)
       在 System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, SqlConnectionString connectionOptions, String newPassword, Boolean redirectedUserInstance)
       在 System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, Object providerInfo, String newPassword, SqlConnection owningObject, Boolean redirectedUserInstance)
       在 System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection)
       在 System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnection owningConnection, DbConnectionPool pool, DbConnectionOptions options)
       在 System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject)
       在 System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject)
       在 System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject)
       在 System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection)
       在 System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory