I am currently building a system for my University project and doing validation for an individuals ID number. I am having difficulty finding validation to make the ID number unique so that it may not be duplicated and each user in the system has a unique ID number, I edited the validation for it to be 13 digits from my phone number validation.... this is my code:
[Required(ErrorMessage = "The ID number field must be completed")]
[RegularExpression(@"^\(?([0-9]{6})\)?[-. ]?([0-9]{4})[-. ]?([0-9]{3})$", ErrorMessage = "Not a valid 13 digit ID number")]
public string id_no { get; set; }