获取异常为没有为一个或多个必需参数提供值

问题描述

我遇到异常，因为一个或多个必需参数未给出值。 如果我使用colsToBeSelected =“ *”（现在进行评论），它可以正常工作，但是使用当前代码，我会报错。

using (var cmd = _oleDbConnection.CreateCommand())
        {
            cmd.UpdatedRowSource = UpdateRowSource.Both;
            var sheets = _oleDbConnection.GetoleDbSchemaTable(OleDbSchemaGuid.Tables,new object[] { null,null,"TABLE" });

            var entityName = typeof(TEntity).Name.ToLower();
            string colsToBeSelected = "";

             if (entityName.IndexOf("alternate_credit_card") > -1)
                colsToBeSelected = isHeaderRowExists ? "[CardRefID],[Key],[MIS_Field1],[MIS_Field2],[ValidatingCarrier],[OtherCarriers],[Card vendor],[Card],[Expiration],[Precedence],[AlertEmail],[maxTktAmt],[IRP_remark] "
                    : "[F1] AS [CardRefID],[F2] AS [Key],[F3] AS [MIS_Field1],[F4] AS [MIS_Field2],[F5] AS [ValidatingCarrier],[F6] AS [OtherCarriers],[F7] AS [Card vendor],[F8] AS [Card],[F9] AS [Expiration],[F10] AS [Precedence],[F11] AS [AlertEmail],[F12] AS [maxTktAmt],[F13] AS [IRP_remark] ";
            //colsToBeSelected = "* ";
            else
                colsToBeSelected = isHeaderRowExists ? "[Value]" : "[F1] AS [VALUE]";

            var sqlQuery = "SELECT " + colsToBeSelected + "FROM[" + sheets.Rows[0]["TABLE_NAME"].ToString() + "] ";

            cmd.CommandText = sqlQuery;

            using (var adapter = new OleDbDataAdapter(cmd))
            {
                excelDs = new DataSet();
                adapter.Fill(excelDs);
            }
        }
    }
}
catch (Exception ex)
{
    throw ex;
}

错误的屏幕截图 Error

文件的标题栏如下

headerfile(columns)

解决方法

暂无找到可以解决该程序问题的有效方法，小编努力寻找整理中！

如果你已经找到好的解决方法，欢迎将解决方案带上本链接一起发送给小编。

小编邮箱:dio#foxmail.com (将#修改为@）