kolosy / furious

an F# DSL for DBMS-independent query

Furious: an F# DSL for DBMS-independent query

Furious is a compact DSL for expressing data queries without relying on an underlying language. The idea is instead of reinventing a new dsl, to use the one already present in the F# base libraries - the functions in the Seq module. Consequently, Furious uses quote literals that encode lambdas operating on the dataset that you want to receive. An example:

module Samples =
    open Furious.Meta

    type person = {
        firstname: string
        lastname: string
        homeAddress: address
        altAddresses: address seq
    }
    and address = {
        street1: string
        zip: string
    }

    type personzip = {
        lastname: string
        zip: string
    }

    let db = Datastore()
    // simple filtering
    // select firstname, lastname, homeAddressId from people p left outer join addresses a on p.homeAddressId = a.addressId where a.zip = '60614'
    let (neighbor: person seq) = 
        db.Yield <@ fun people-> Seq.filter (fun p -> p.homeAddress.zip = "60614") people @>

    // count
    // select count(*) from people p left outer join addresses a on p.homeAddressId = a.addressId where a.zip = '60614'
    let (neighbors: int seq) = 
        db.Compute <@ fun people -> Seq.length <| Seq.filter (fun p -> p.homeAddress.zip = "60614") people @>

    // mapping
    // select lastname, zip from from people p left outer join addresses a on p.homeAddressId = a.addressId where a.zip = '60614'
    let (neighborsByZip: personzip seq) = 
        db.Yield <@ fun people -> Seq.collect (fun p -> seq { for address in p.altAddresses -> { lastname = p.lastname; zip = address.zip } }) people @>

This style lets you build type-safe expressions, with the resulting type being the only thing you have to explicitly declare..

Status

Furious has become a functioning proof-of-concept. Work is underway to turn it into a usable product. It is currently pre-alpha.

Tasks

• Encapsulate raw sql into dialects (ongoing)
• Add join directionality tracking (left|right|inner) (done)
• Add state tracking (insert v update)
• Add transaction handling
• Clean up column naming in generated sql
• Refactor record serialization/deserialization (works, but code's hard to follow)