Question

I have integer type field in database which is having property ‘Not Null’.

when i create a view & do a validation, if i left that field blank, it will consider it as 0 so i can not compare it with 0 because if someone insert a value 0 then it will be considered as error!

one another problem is that i am using Model error as described in the book ‘ASP.NET MVC 1.0’ @ Scott Gu blog. And I am checking the value in partial class of object (created by LINQ-To-SQL). i.e

public partial class Person {     public bool IsValid     {         get { return (GetRuleViolations().Count() == 0); }     }     public IEnumerable<RuleViolation> GetRuleViolations()     {         if (String.IsNullOrEmpty(Name))             yield return new RuleViolation('Name is Required', 'Name');         if (Age == 0)             yield return new RuleViolation('Age is Required', 'Age');         yield break;     }     partial void OnValidate(ChangeAction action)     {         if (!IsValid)             throw new ApplicationException('Rule violations prevent saving');     } } 

There is also problem with range.

Like in database if i declared as smallint i.e. short in c#, now if i exceed that range then it gives error as ‘A Value is reguired’.

so finally is there any best way for validation in ASP.NET MVC?

Answer 1

you can change your code with a nullable type?

    Dim i As Nullable(Of Integer)       MsgBox(i.HasValue)     'result is false      i = 1     MsgBox(i.HasValue)     'result is true      i = Nothing     MsgBox(i.HasValue)     'result is false