Overview

Simple embedded DSL for making SQL-like queries. Now supports SELECT, INSERT, UPDATE and DELETE commands.

Working with DSL

Defining entities

Define "user" entity with "id" and "name" :: (define-entity user user_table ; DB table name (id name)) ; fields list

Defining connection

Connection used implicitly to execute all commands :: (define-current-connection #:database "test" #:password "test" #:user "test")

Making queries

Select queries has following format :: (select ENTITY [where CONDITIONS] [order-by FIELD asc/desc])

For example :: (select user) ; SELECT id,name FROM user_table (select user [where (and (> id 1) (< id 3))]) ; SELECT id,name FROM user_table WHERE ((id > '1') and (id < '3')) (select user [order-by name asc]) ; SELECT id,name FROM user_table ORDER BY name ASC

Select returns list of user structs. User field can be accessed with standard struct selectors (user-id, user-name) :: (define (print-users user-list) (for ([user user-list]) (printf "Id: ~a, name: ~an" (user-id user) (user-name user))))

Insert/Update

Creating user :: (insert user (user 1 "John Doe"))

Rename user :: (define (rename-user target-user new-name) (update user (struct-copy user target-user [name new-name])))

Delete

You can delete entity instance after selecting it. :: (define (delete-user-by-id id) (let ([selected-user (first (select user [where (= id id)]))]) ; assuming, that user with given id exists (delete user selected-user)))