public IEnumerable <ValidationResult> Validate(ValidationContext validationContext) { // Sql injection validation on text strings. just matching to keywords in sql to block unwanted injections. if (Country.Contains("Delete") || Country.Contains("Alter") || Name.Contains("Delete") || Name.Contains("Alter") || Adress.Contains("Delete") || Adress.Contains("Alter")) { yield return(new ValidationResult( $"Any sql keywords are banned.", new[] { nameof(Country) })); } }