Question

我有以下代码：

public static List<ResponseSupplier> Feza_ReturnSuppliers(string country, string locale, string rtype, string scat, string sscat, string bill, int? comp, double? inc, int? loi, bool? fc, int? hf)
    {
        string query = string.Format(Queries[SqlQueries.returnquery], country, locale, rtype, scat, sscat, bill, comp, inc, loi, fc, hf);
        IList<ExpandoObject> suppliersRaw = DatabaseHelper.MultiResponseComplex(conn, query,
            new List<string>
            {   "SupID",
                "SupName",
                "Tlabel",
                "Tcode",
                "dcstatic",
                "dcur",
                "dse",
                "ltz",
                "st",
                "isamp",
                "minf",
                "sf",
                "cpt",
                "Scoring",
                "TrustCoefficient",
                "ApiIntegrated",
                "fapi"
            });

        return suppliersRaw.Select(e => new ResponseSupplier

        {
            SupID = (((dynamic)e).SupID.ToString()) as string,
            SupName = (((dynamic)e).SupName) as string,
            Tlabel = (((dynamic)e).TierLabel) as string,
            Tcode = (int?)(((dynamic)e).Tcode),
            dcstatic = (double?)(((dynamic)e).dcstatic),
            dcur = (((dynamic)e).dcur) as string,
            dse = (((dynamic)e).dse) as string,
            ltz = (((dynamic)e).ltz) as string,
            st = (((dynamic)e).st) as string,
            isamp = (bool?)(((dynamic)e).isamp),
            minf = (double?)(((dynamic)e).minf),
            sf = (double?)(((dynamic)e).sf),
            cpt = (string)(((dynamic)e).cpt),
            Scoring = (double?)(((dynamic)e).Scoring),
            TrustCoefficient = (double?)(((dynamic)e).TrustCoefficient),
            ApiIntegrated = (bool?)(((dynamic)e).ApiIntegrated),
            fapi = (bool?)(((dynamic)e).fapi)

    }).ToList();

我收到以下错误：'Cannot convert type 'System.DBNull' to 'double?'' 这是因为在db中，我可以将Null表示为：“ TrustCoefficient”和“ Scoring”。我如何克服错误，请注意，当我为null时，我不想获得类似“ 0”的值。那是因为我需要将此列表的结果与另一列表的结果进行比较（并且该列表的参数显示为空）。有没有一种方法可以转换或解析

            Scoring = (double?)(((dynamic)e).Scoring),
            TrustCoefficient = (double?)(((dynamic)e).TrustCoefficient),

允许DBNull并在结果中显示Scoring = Null吗？

Answer 1

尝试一下：

method

您将需要检查每个列的值是否都是DBNull

List <model>允许DBNull

1 个答案: