Comments on: What’s Wrong with a Data-Driven Approach?

By: Jan Van Ryswyck

Jan Van Ryswyck — Thu, 04 Sep 2008 20:01:03 +0000

Thx for the kind words.

By: Colin Jack

Colin Jack — Thu, 04 Sep 2008 15:37:35 +0000

Nice post, keep up the good work.

By: Mark

Mark — Thu, 04 Sep 2008 01:31:12 +0000

“SQL is also (the best way I can think of) to perform deep subqueries to extract, cache, and visualize magic nuggets of live data from your well-indexed tablespaces.”

SQL is not just for RDBMS.

“It’s not just for “crud”.”
That’s what he said.

By: Scott Fitchet

Scott Fitchet — Wed, 03 Sep 2008 16:32:03 +0000

“They’re just another piece of software to efficiently store data on disk. That’s all!”

SQL is also (the best way I can think of) to perform deep subqueries to extract, cache, and visualize magic nuggets of live data from your well-indexed tablespaces.

It’s not just for “crud”.

By: Mark

Mark — Wed, 03 Sep 2008 12:37:43 +0000

It really doesn’t need a parameter object (DTOs and VOs have different purposes) for that few of parameters.

And Greg, it actually might NOT make more than one trip to the db. That is another advantage (beauty) of this.

By: Jan Van Ryswyck

Jan Van Ryswyck — Tue, 02 Sep 2008 18:34:11 +0000

Although not shown in the first example (for simplicity), there would probably be a check for a valid order ID and a valid product ID (never trust input from the user). Then you have three DB calls as well.

By: Greg Beech

Greg Beech — Tue, 02 Sep 2008 07:22:43 +0000

So in terms of performance, the first example will execute with one round-trip to the database. The second example will need three. I hope the site this is supporting never needs to scale to a decent number of users because it won’t.

By: Dew Drop - August 30, 2008 | Alvin Ashcraft's Morning Dew

Dew Drop - August 30, 2008 | Alvin Ashcraft's Morning Dew — Sat, 30 Aug 2008 23:23:39 +0000

[...] What’s Wrong with a Data-Driven Approach? (Jan Van Ryswyck) [...]

By: Jan Van Ryswyck

Jan Van Ryswyck — Sat, 30 Aug 2008 09:20:50 +0000

Yes, you’re right. It would probably be an application service taking a CartItem DTO, but I didn’t want to overload the simplest example I could think of.

By: Greg Young

Greg Young — Fri, 29 Aug 2008 21:45:00 +0000

Just to be nit picky …

That’s not a [Domain Service] its an [Application Service]

Also why not introduce a CartItem value object instead of multiple parameters.

public void AddItem(CartItem _Item)

Ok I am done. Good post