Notes on SQL-first application development, the TSQL.APP framework, and building business software directly in the database.
In TSQL.APP a screen and its buttons are rows in the database, so changing the application is an update, not a release. Why that is safe, and what it does not protect you from.
We wrote a new front end for TSQL.APP in Vue, from an empty folder. It renders every existing application unchanged, because no application was ever in the front end to begin with.
Business software has to produce documents. TSQL.APP generates them from a Word template and the card metadata you already wrote — no reporting tool, no second data model.
The schema is the part nobody will let you touch, and rightly so. TSQL.APP puts the application in a second database that reads yours through synonyms — and the binding between them is not configured anywhere.
A T-SQL batch cannot block for forty seconds while someone types, so in TSQL.APP nothing does. The script ends and is re-run from line 1 on the next click, and "step 3 of 5" is never stored anywhere.
Will it not hammer the database? That question is borrowed from consumer platforms. Business software has bounded users, unforgiving writes, and the opposite scarce resource.
Most AI features keep a stale copy of your schema and a guardrail written in English. Put the assistant in the database and SQL Server enforces its limits.
TSQL.APP puts the whole application inside SQL Server — UI, business logic and permissions. Why the frontend-backend divide turns out to be optional.
The expensive part of a business application is not the licence. It is that after a few years nobody dares touch the server. Here is what changes.
A message sent inside an open transaction has not been sent. The Service Broker trap that makes the obvious implementation fail every single time.
COM objects, the command shell, Excel automation — the Windows-only half of SQL Server. What replaced it on Linux, and why one procedure was enough.
Most business software ends up married to the server it was installed on. When the application is the database, the host underneath becomes replaceable.