Re: Making LuaSQL roar?

[PA <petite.abeille@...>]

On Aug 14, 2005, at 15:06, Klaus Ripke wrote:

> What would such a tool do, mapping which object system?

Forget 'objects'. Think plain Lua tables then.

> Isn't most of the OR/M work about type mapping,

No. They are mostly about relationships mapping and object graphs.

> which is mostly a non-issue with Lua?

Types? From Lua's point of view, they are not that interesting indeed  
as they are mostly reduced to string vs number.

> Or would you want to set up set methods derived
> from constraints found in the DB?

Yes.

> Or have Lua errors trigger DB rollbacks?

Hmmm...?!?

> Or have "finally" commit?

Autocommit?

> Use yet more new syntax for transactions?

Hopefully not.

> Don't grasp how this would apply to Lua!?
> Could you describe a real problem which could have a mucher
> nicer solution using some O/RM?

Automatic relationship resolution perhaps?

Say you have two (SQL) tables: Movie and Studio. With a one-to-one  
relationship from 'Movie' to 'Studio' and a reverse one-to-many  
relationship between Studio and Movie. After fetching, you could now  
query your (Lua) table like such:

local aStudio = aMovie.studio
local someMovies = aStudio.movies

Furthermore, you could say:

aMovie.studio = anotherStudio

And have the library transparently handle the resulting  
updates/deletes, etc...

> Wouldn't we need a "full fledge" object system first?

Forget the "object system". Lua has none. Lets stay focus on the T/RM  
mapping for a second :)

> Could you give hints what could be improved in plain lua-style
> use of LuaSQL?

Mostly automatic relationships resolution, manipulation and related  
nastiness like row uniquing, faulting and such:

http://developer.apple.com/documentation/Cocoa/Conceptual/CoreData/ 
Articles/cdFaultUniquing.html

Cheers

--
PA, Onnay Equitursay
http://alt.textdrive.com/