[GSOC] Database API draft proposal

[Piotr Szturmaj]

Fawzi Mohamed wrote:
> Well the comments in there are what is important, and will need to be
> specified better IMHO.
>
> The most important part in my opinion is how one chooses to represent a
> record.
> A big design choice is if the various fields are defined at compile time
> or at runtime.
> Also how does one add special behavior to a record? Do you use a
> subclasses of the generic record type (as ruby does for example)?

I'm working on DB API for few months in my spare time. I'm delayed that 
much by my other projects. Please take a look at my ideas:

http://github.com/pszturmaj/ddb

Documentation:
http://pszturmaj.github.com/ddb/db.html
http://pszturmaj.github.com/ddb/postgres.html

In my code, row is represented using struct DBRow!(Specs...). Fields may 
be known at compile time or not. DBRow besides base types, may be 
instantiated using structs, tuples or arrays. Untyped row (no compile 
time information) is DBRow!(Variant[]).

Typed rows are very useful, for example you don't need to manually cast 
columns to your types, it's done automatically, e.g.:

auto cmd = new PGCommand(conn, "SELECT typname, typlen FROM pg_type");
auto result = cmd.executeQuery!(string, "typName", int, "len");

foreach (row; result)
{
     // here, row DBRow subtypes
     // a Tuple!(string, "typName", int, "len")
     writeln(row.typName, ", ", row.len);
}

What do you think? :)