2014-08-11

SQL in S-Expression

There is SXML which represents XML in S-Expression. If you're a professional programmer, it is very difficult to avoid using SQL (well, if you could, you are very lucky).

Writing SQL isn't so bad if the file is separated or the editor is smart enough to edit. However it's usually none of the case so I always need to suffer especially writing it in double quote. Now, Emacs is de-facto editor for all programmers (vim? why are you talking about jeans here? V.I.M.) and it's by default very good with editing s-expression. So if you can write SQL in s-expression then the world would be happier than before.

Now, there are bunch of projects that have the same idea I've got, CLSQL, SxQL, S-SQL for example (I think Clojure also has something similar but I'm not so familiar). The problem of them are very simple. It's using keyword which is not in R6RS/R7RS. Moreover, those use either reader macro or CLOS so not pure s-expression. What I want is light weight but easy to edit. (well, it is actually ok for me, Sagittarius has all of them anyway.)

So I'm thinking something like following;
(define ssql 
  '(select ((p id) (as (p first_name) name) (a street))
    (from (as person p))
    (inner-join (as address a) (on (= (p id) (a id_person))))
    (where (= (a country) "Nederlands"))))

(ssql->sql ssql)
;; "select p.id, p.first_name as name, a.street
;;  from person as p
;;  inner join address as a on p.id = a.id_person
;;  where a.count = 'Netherlands'" 
Hmmm, it looks parentheses are a bit too many so the readability is a bit lowered. Basically it doesn't have to be fancy but readable and easy to remember. So one-by-one mapping is ok. (if I want  OR-mapper, then I just need to construct it on top of it.)

If there is something similar in Scheme or better idea, I would like to know.

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