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Jeremy · Guest

I am creating a Web Application and wish to use the 3 layer approach
Presentation - Logic - DB Layer

However I am stuck as to where I separate the Logic from the business
layer to the DB Layer and how I should extend my classes in the future.

eg

type TAssessmentDetails = class(TAdvObject)
public
FID : Integer;
Fassessname : String;
Fcalyear : String;
Fgroupcode : String;
constructor Create;
published
property ID : Integer read FID write FID;
property assessname : String read Fassessname write Fassessname;
property calyear : String read Fcalyear write Fcalyear;
property groupcode : String read Fgroupcode write Fgroupcode;
end;

type TAssessmentDB = class
private
function GetConnectionString:string;
public
function GetAssessmentDetails(sSchoolID : String;iID: Integer) :
TAssessmentDetails;
end;

So should down the track I need to extend the functionality of
TAssessmentDetails ie TXTRAAssessmentDetails = class(TAssessmentDetails)
the original GetAssessmentDetails function no longer works because it
is of type TAssessmentDetails.

Maybe I need to design it better? Any advise/links appreciated.

Jeremy

Joanna Carter (TeamB) · Guest

"Jeremy " <jeremy@ lanwest dot com dot au> a écrit dans le message de news:
[email]41dba53e (AT) newsgroups (DOT) borland.com[/email]...