方法'{0}'不支持SQL转换

Question

I was doing mapping with wildcards. I get this error because the definition of the rule to be searched only comes from a table.

I do not know exactly how right I am doing this here, but as a result I have a mistake and I expect your help.

public class Ekstre   
{
    private readonly DataClasses1DataContext db = new DataClasses1DataContext();
    private readonly KdrGnyClassesDataContext kg = new KdrGnyClassesDataContext();

    public bool check { get; set; }
    public int Id { get; set; }
    public DateTime Tarih { get; set; }
    public string Kodu { get; set; }
    public string Açıklama { get; set; }
    public decimal Tutar { get; set; }
    public string bankaKod { get; set; }
    private string kod = null;

    public string muhKod {
        get { return kod = kg.kuralTanimlari
                             .FirstOrDefault(a => Regex.IsMatch(Açıklama, WildCardToRegular(a.kural))).hesapKodu;
            }
        set { kod = value; }
    }

    private string hesap = null;

    public string hesapAdi {
        get { 
            hesap = !string.IsNullOrWhiteSpace(muhKod) ? db.MUHHESAP.First(p => p.MUHKOD == muhKod).MUHADI1 : null;
            return hesap;
        }
        set => hesap = value;
    }

    public string kodTipi { get; set; }
}

public static string WildCardToRegular(string value) 
{
    return "^" + Regex.Escape(value).Replace("\\?", ".").Replace("\\*", ".*") + "$";
}

Answer 1

You can only use supported functions on dbcontext queries over IQuerable. You have two options 1. Fire db query by doing ToList() or ToArray() and then .FirstOrDefault(.....) This has a drawback that it will fetch all records from db and then apply your function to results.

2. Convert your filtering function to a simple sql supported function. As far as i know Regex is not supported in entity framework

Answer 2

public string muhKod {
        get
        {
            var firstOrDefault = kg.kuralTanimlari.ToList()
                .FirstOrDefault(a => Regex.IsMatch(Açıklama, WildCardToRegular(a.kural)));
            if (firstOrDefault != null)
                 kod = firstOrDefault.hesapKodu;
            return kod;
        }
        set => kod = value;
    }

It works so beautifully. Thank you.