c# - 多步 OLE DB 操作产生错误。检查每个 OLE DB 状态值（如果可用）。没有工作

Question

对于以下代码，我收到多步 OLE DB 操作错误。

适配器正在填充数据集时引发错误（在此行sAdapter.Fill(sDs, "Tran");：）

OleDbCommand sCommand;
OleDbDataAdapter sAdapter;
OleDbCommandBuilder sBuilder;
DataSet sDs;
DataTable sTable;

OleDbConnection connection = new OleDbConnection();
connection = PEConnectionManager.ConnectionManager.GetConnection();
connection.Open();

string sql = "Select * Frequency from Tran where frequency=?";
sCommand = new OleDbCommand(sql, connection);
//string sfrequency = "Quarterly";
OleDbParameter param = new OleDbParameter("Quarterly", OleDbType.VarChar);

sCommand.Parameters.AddWithValue("frequency",param);

sAdapter = new OleDbDataAdapter(sCommand);
sBuilder = new OleDbCommandBuilder(sAdapter);
sDs = new DataSet();
sAdapter.Fill(sDs, "Tran");      // Error is thrown here...
sTable = sDs.Tables["Tran"];
sCommand.Prepare();
connection.Close();