Question

I am working on an import assistant (C# .NET 4) between 2 MS Access databases and I need to implement a mechanism to ensure data consistency.

Example:

Import persons.

Problem:

The columns from the person tables have different column sizes.

Source Table: Address column size = 50;

Destination Table: Address column size = 30;

When we try to import a person with a Address larger than 30 chars a problem appears.

Desired solution:

When the previous problem appears a dialog needs to be shown where the user can redefine or truncate the value to correspond to the require length.

Import function looks something like this

private static void ImportPerson()
{
    var sourcePerson = sourcePerson.GetObject();
    if (sourcePerson == null)
        return;

    var person = new MyPerson();
    person.Address.Value = sourcePerson.Address;    
    person.Company.Value = sourcePerson.Company;
    person.Save();  
}

I have metadata information stored in my objects witch allows me to access the column size of my destination columns.

person.Address.ColumnSize

So I can do something like this after filling business objects with the new values.

if (person.Address.ColumnSize.CompareTo(person.Address.Value.Length)) < 0
    // show dialog ...

Unfortunately this means checking all the properties (Address, Company… and other) individually.

I am looking for a more generic approach where I don’t need to check every property individually.

Any ideas, suggestions, thoughts would be highly appreciated.

Answer 1

Presumably, the members of your class (Adress, Company, etc) are all objects of the same type, since they seem to have consistent properties that you’re using for metadata. Add a method to your MyPerson class to provide access to its properties by iterating, e.g.

class MyPerson {

    public IEnumerable<MemberClass> Properties
    {
        get {
            yield return Adress;
            yield return Company;
            ...
        }
    }  
    ...
}

Then

foreach (MemberClass prop in person.Properties) {
    if (prop.ColumnSize.CompareTo(prop.Value.Length) < 0)
       // show dialog ...
    }
}

It would probably also make sense to collect all the failures in a list and just show a single dialog for the record, to make life easier for the user.