“Specified cast is not valid” in LINQ when DateTime field is null

Question

I got a problem. This my code use a LINQ.

var resultCases = from row2 in dtCases.AsEnumerable()
                  where row2.Field(\"caseID\") == case         


        

Answer 1

Update: try this

public static class ConversionExtensions
{
    public static string SafeDateTime(this object value)
    {
        if (value == DBNull.Value) return string.Empty;

        var valueType = value.GetType();
        if (typeof (DateTime?).IsAssignableFrom(valueType))
        {
            var nullableValue = value as DateTime?;
            if (nullableValue == null) return string.Empty;
            return nullableValue.Value.ToString();
        }
        if (typeof (DateTime).IsAssignableFrom(valueType))
        {
            return ((DateTime) value).ToString();
        }
        return string.Empty;
    }
}

Called with:

effectiveDate = row2["caseEffectiveDate"].SafeDateTime()