Sorry for a 10 hour delay. Been out all day In simple terms. In both databases the data is stored identically. It is only the way I retrieve data that is different.
TEvent Property EventID:integer; Property DateCreated:TDatetime Property EventDescription:string End; TBigEvent = class(TEvent) Property More:string; End; In this case I would have two tables like so Create table TEvent ( ClassType Integer EventID DateCreated EventDescription ) And Create Table TBigEvent ( EventID More ) And View vTevent = select * from TEVent And View vTBigEvent = select * from TBigEvent joining to TEvent Now in interbase I would have 2 procedures for retrieving GetTEvent(EventID) returns EventID,DateCreated,EventDescription GetTBigEvent(EVentID) returns EventID,DateCreated,EventDescription,More But with mssql I can do something more like (Also this is all pseudo junk not to be taken as real code) Stored Procedure GetTEvent(EventID) begin select classtype from tevent where eventide = eventide if classtype = TEvent then result := select * from TEvent else if classtype = TBigevent then result := select * from tvbigevent end; in Interbase you cannot return different resultsets which contain different columns. So its really just a handy thing. In interbase I would prequery the database to get the classtype, and then call the correct procedure, so its more of less calls to the db and easier to read code. Now oracle may have all the same features etc of MSSQL I don't know. In the way I retrieve objects, interbase was actually faster at retrieving and saving my objects into the database. A MAJOR factor of this is the speed of getting the primarykey via a generator is so much faster than what you have to do with MSSQL. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Todd Martin Sent: Thursday, 1 June 2006 10:40 a.m. To: NZ Borland Developers Group - Delphi List Subject: Re: [DUG] Why InterBase So what's the difference between the MSSQL approach and submitting an SQL query on any database with the same conditions? Are you defining a table for each class in your class heirarchy? On Wed, 31 May 2006 18:55, Kyley Harris wrote: > In MSSQL you can return > different rowed data based on conditions. When using the database to > store classed data with polymorphing this is great. It means that When I > ask for a TClient from a stored procedure passing it a primary key, it > can work out if the key is for a TClient, or a TBetterClient, and return > the correct result set to be processed. IB/FB cant do that, which makes > for more overhead. I've always found writing server side in IB a pain in > the ass. _______________________________________________ Delphi mailing list [email protected] http://ns3.123.co.nz/mailman/listinfo/delphi _______________________________________________ Delphi mailing list [email protected] http://ns3.123.co.nz/mailman/listinfo/delphi
