I have a table with a column that I need to change it's values before comparing with a .Where().

Take this example: if the value in db is 'My sTriNg', I want to transform to 'my_string' before comparing.

Is there a lightweight algorythm to do this?

UPDATE: So after the answer I realized that I can do this:

public static string RemoveAccentsAndSpaceFromField(this string sNomenclature)
    {
        StringBuilder sbReturn = new StringBuilder();
        var arrayText = sNomenclature.ToLowerInvariant().Normalize(NormalizationForm.FormD).ToCharArray();
        foreach (char letter in arrayText)
        {
            if (CharUnicodeInfo.GetUnicodeCategory(letter) != UnicodeCategory.NonSpacingMark)
                sbReturn.Append(letter);
        }

        string sNoAccents = sbReturn.ToString();

        string sNoSpaces = sNoAccents.Replace(" ", "_");

        return sNoSpaces;
    }

Then use it like this:

using (var oContext = new MyContext())
{
    bool bFieldExists = oContext.Fields.Any(s => s.Nomenclature.RemoveAccentsAndSpaceFromField() == sFieldName && s.id != iFieldId);
}

CodePudding user response：

No need to transform the actual value. You can do this.

string StringToCompare = "my_string";

var FilteredList = DbContext.TableName
     .Where(i => i.ColumnName.ToLower().Replace(' ', '_') == StringToCompare.ToLower())
     .ToList();