https://trysil.lastrucci.net/Tutorials, deep dives, and release notes for Trysil — an ORM framework for Delphi. 2026-09-08T17:54:25+02:00 David Lastrucci https://trysil.lastrucci.net/ Jekyll © 2026 David Lastrucci /assets/img/favicons/favicon.ico /assets/img/favicons/favicon-96x96.png 2026-08-30T07:38:00+02:00 2026-08-30T07:38:00+02:00 https://trysil.lastrucci.net/posts/the-identity-map-what-it-gives-you-what-it-hides/ David Lastrucci

Here’s a pattern that shows up in almost every ORM-backed codebase, written by people who don’t realize it: LOrder := LContext.Get<TOrder>(42); // ... do something ... LOtherOrder := LContext.Get<TOrder>(42); Is LOrder = LOtherOrder? With most ORMs, no — you get two distinct objects holding the same data. With Trysil and the identity map on, yes — you get the same object, because...

2026-08-16T08:04:00+02:00 2026-08-16T08:04:00+02:00 https://trysil.lastrucci.net/posts/lazy-loading-ttlazy-and-ttlazylist/ David Lastrucci

A TOrder has a CustomerID. Sometimes, when the code holds an order, it also needs the Customer. Sometimes it doesn’t. A naïve ORM fetches the customer eagerly on every Get<TOrder>. That’s simple but wasteful — you pay for a second query (or a bigger join) even when nobody asked. An aggressive ORM proxies the property: the customer object exists lazily, and the first access triggers the f...

2026-08-02T08:19:00+02:00 2026-08-02T08:19:00+02:00 https://trysil.lastrucci.net/posts/optimistic-locking-with-ttversion/ David Lastrucci

Two users open the same invoice. Alice edits the amount and clicks Save. Bob, a minute later, edits the customer and clicks Save. Alice’s amount is gone. Bob overwrote it with the value he loaded a minute ago. This is not a bug in Bob’s code. It’s the default behavior of every ORM ever written, unless you tell it not to do that. The fix — optimistic locking — is older than most frameworks usin...

2026-07-19T07:52:00+02:00 2026-07-19T07:52:00+02:00 https://trysil.lastrucci.net/posts/events-in-trysil-the-full-lifecycle/ David Lastrucci

The previous post ended with a promise: after hooks exist, we’ll come back to them. This is that post. Trysil has two complementary mechanisms for reacting to persistence operations. One is the method-hook approach from the validation post — [TBeforeInsert], [TBeforeUpdate] and friends, lightweight in-class procedures. The other is the event class mechanism, which you reach for when the reacti...

2026-07-05T08:41:00+02:00 2026-07-05T08:41:00+02:00 https://trysil.lastrucci.net/posts/validation-attributes-and-beforeinsert-beforeupdate-hooks/ David Lastrucci

Most ORMs treat validation as someone else’s problem. You write your entities; you write your service layer; somewhere in that service layer there’s a Validate(entity) method that nobody maintains because nobody knows where to put the rules. Trysil makes a different bet: validation belongs on the entity, right next to the column definition. Two kinds of rules cover almost everything — declarat...