# Creatulator: Before I go and make it myself, does this exist **URL:** \ **Category:** Rails\ **Created:** [March 8, 2006, 11:57am UTC](https://www.ruby-forum.com/t/creatulator-before-i-go-and-make-it-myself-does-this-exist/78371 "2006-03-08T11:57:14Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Mason](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/da6949/32.png) [@Mason](https://www.ruby-forum.com/u/Mason)\ **Post date:** [March 8, 2006, 11:57am UTC](https://www.ruby-forum.com/t/creatulator-before-i-go-and-make-it-myself-does-this-exist/78371/1 "2006-03-08T11:57:14Z")
Basically, on thing that annoys me to no end is that I am constantly having to add things to my model that could just be reflected out by the active record. I use PortGres exclusivly, and I know that there are ways to ask the database things like, “what is the primary key” “what relation does this foreign key belong to” etc… So what I am about to go and write myself is a database introspector that will look at a database and create all the Models for every table for me, including all the set\_primary\_key, all the has\_many belong\_tos, and many, if not all, of the validates\_blah based on the database constraints. This is going to be quite an undertaking, so before I go and do it, does anyone know of something that already does this that has been previously written? ---
**Author:** ![Mason](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/da6949/32.png) [@Mason](https://www.ruby-forum.com/u/Mason)\ **Post date:** [March 8, 2006, 6:56pm UTC](https://www.ruby-forum.com/t/creatulator-before-i-go-and-make-it-myself-does-this-exist/78371/2 "2006-03-08T18:56:21Z")
Mason [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) writes: > Basically, on thing that annoys me to no end is that I am constantly > having to add things to my model that could just be reflected out by > the active record. I use PortGres exclusivly, and I know that there > are ways to ask the database things like, “what is the primary key” > “what relation does this foreign key belong to” etc… ActiveRecord extensively uses introspection. There are already methods built for finding out all these. For any model call the method ‘Methods’ and it will return you the list of methods. Try them and find out whether what you need is already there or not. – Surendra S. [http://ssinghi.kreeti.com](http://ssinghi.kreeti.com), [http://www.kreeti.com](http://www.kreeti.com) Read the latest news at: [http://news.kreeti.com](http://news.kreeti.com) ,---- | Great wits are sure to madness near allied, | And thin partitions do their bounds divide. | | (John Dryden, Absalom and Achitophel, 1681) `---- ---
**Author:** ![Mason](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/da6949/32.png) [@Mason](https://www.ruby-forum.com/u/Mason)\ **Post date:** [March 9, 2006, 4:58pm UTC](https://www.ruby-forum.com/t/creatulator-before-i-go-and-make-it-myself-does-this-exist/78371/3 "2006-03-09T16:58:17Z")
Mason wrote: > This is going to be quite an undertaking, so before I go and do it, > does anyone know of something that already does this that has been > previously written? Don’t bother. Forget about SQL and the database completely (well almost completely) and switch to Rails migrations. Then you can build your schema in Ruby and let rails do the primary key stuff in the background. To Rails the database is just a fancy filestore that we have to use because the filesystems haven’t evolved as much as we’d like and object databases are mostly crap. Constraints should be implemented in your object model, and validated via your test suite. Let the database just serve data and deal with the concurrency issue. It’s a mental paradigm shift - stop checking things in two different places. NeilW ---
**Author:** ![Mason](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/da6949/32.png) [@Mason](https://www.ruby-forum.com/u/Mason)\ **Post date:** [March 9, 2006, 6:04pm UTC](https://www.ruby-forum.com/t/creatulator-before-i-go-and-make-it-myself-does-this-exist/78371/4 "2006-03-09T18:04:40Z")
On 3/9/06, Neil W. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Mason wrote: > > > This is going to be quite an undertaking, so before I go and do it, > > does anyone know of something that already does this that has been > > previously written? > > Don’t bother. Forget about SQL and the database completely (well almost > completely) and switch to Rails migrations. Then you can build your > schema in Ruby and let rails do the primary key stuff in the background. OK, one my Rails app works with legacy PostgreSQL database (also accessed from non-Rails environments), there are views, stored procedures, schemas, composite keys, explicitly defined foreign keys with CASCADE/RESTRICT options, non-serial primary keys (varchars), indexes, CHECK and DEFAULT constraints for columns; triggers; domain types. Rails migrations, with their idea of logic in application only and “least common denominator” support for databases just can’t handle all that and aren’t that useful for me, so I stick with pure SQL incremental updates. ---
**Author:** ![Mason](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/da6949/32.png) [@Mason](https://www.ruby-forum.com/u/Mason)\ **Post date:** [March 9, 2006, 6:14pm UTC](https://www.ruby-forum.com/t/creatulator-before-i-go-and-make-it-myself-does-this-exist/78371/5 "2006-03-09T18:14:03Z")
On 3/8/06, Mason [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > So what I am about to go and write myself is a database introspector > that will look at a database and create all the Models for every table > for me, including all the set\_primary\_key, all the has\_many > belong\_tos, and many, if not all, of the validates\_blah based on the > database constraints. Regarding associations, yes, it is possible to generate models automatically with set\_primary\_key, has\_many and has\_one declarations, but I suspect that manual tweaking still will be needed, e.g. when you want to change name of the association, or use class names that don’t correspond literally to names of database tables. And what about refreshing so generated models? Schema namespace support? And about validations: it is possible to define one universal validate\_against\_db\_constraints method, that would check all CHECK and FOREIGN KEY constraint using single query to database and providing rich feedback - what constraints are broken and which columns break them 🙂