Calypso: Related work that might be useful.

[kevinswiber]

Howdy.

This repo just popped up on my radar.

I'm doing something similar with kevinswiber/calypso.

You can find all the query language parsing code here: https://github.com/kevinswiber/calypso/tree/master/compiling

I'm using Jison to generate a SQL parser. It doesn't fully conform to any SQL standard, but it's a start.

The goal of Calypso is to provide a common query language that can be implemented on top of any queryable data source. I have drivers for MongoDB and a Backend-as-a-Service called Usergrid. Calypso was born out of another project. I still need to port over older CouchDB and Salesforce drivers.

It also has a data mapper associated with it for automatically hydrating query results into object models.

The source code is released under the MIT license (my employer, Apigee, holds the copyright).

Here's a usage example: https://gist.github.com/kevinswiber/44542186e5dbc5bd03c6

Anyway, the point is... there might be some code you can steal from Calypso to serve your interests. If so, have at it!

Cheers!

[heapwolf]

Very cool man! This is great work and I'm sure that it will be a valuable code read. I'd love to discuss more, and it seems like you have lots of domain knowledge! hey, if you use IRC you should hop into #stackvm and ##leveldb on freenode for mad science party. :)

[kevinswiber]

So... as the world turns, and it's now 9 months later...

I wrote a persistent key-value store for Node early last year, https://github.com/argo/medea. I now have a project that needs it. Also, @kesla has created an implementation of AbstractLevelDOWN for Medea, https://github.com/kesla/medeadown.

My project is going to need SQL queries. As linked above, I happen to know a thing or two about parsing SQL. While I was going to create a SQL implementation that only works with Medea, it seems a shame to not extend that to the wider LevelUP community.

Have you seen enough interest in this project that the Node/LevelDB community would benefit? Otherwise, I may just couple to Medea functionality rather than going through the AbstractLevelDOWN interface.

Cheers.

[heapwolf]

The parsing/lexing is actually complete (to spec) what's missing is the
mapping between the parsed-ast and level-*, which shouldn't be too hard if
there are a few people working together on it ;)

On Tuesday, July 22, 2014, Kevin Swiber notifications@github.com wrote:

So... as the world turns, and it's now 9 months later...

I wrote a persistent key-value store for Node early last year,
https://github.com/argo/medea. I now have a project that needs it. Also,
@kesla https://github.com/kesla has created an implementation of
AbstractLevelDOWN for Medea, https://github.com/kesla/medeadown.

My project is going to need SQL queries. As linked above, I happen to know
a thing or two about parsing SQL. While I was going to create a SQL
implementation that only works with Medea, it seems a shame to not extend
that to the wider LevelUP community.

Have you seen enough interest in this project that the Node/LevelDB
community would benefit? Otherwise, I may just couple to Medea
functionality rather than going through the AbstractLevelDOWN interface.

Cheers.

—
Reply to this email directly or view it on GitHub
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Paolo Fragomeni
Founder, Here is How
http://hereishow.to

github.com/hij1nx
twitter.com/hij1nx

[kevinswiber]

I actually don't need SQL ANSI/ISO specification conformity. I'm using Calypso Query Language (https://github.com/kevinswiber/caql), which will likely merge in some features of N1QL (https://github.com/couchbaselabs/tuqtng/blob/master/docs/n1ql-v1.md) down the road.

I worked on getting it wired up to Medea today, and that appears to be working well (so far).

I think I can make this code modular enough so that it's trivial to implement LevelDOWN compatibility, so I may end up doing both. Thanks for your thoughts!

[kevinswiber]

Just to follow up...

I've got some initial support for CaQL and LevelUP. Not being super-familiar with LevelUP, I'm certain there is room for improvement.

level-caql: https://github.com/kevinswiber/level-caql

medea-caql: https://github.com/kevinswiber/medea-caql

caql-js-compiler: https://github.com/kevinswiber/caql-js-compiler

Cheers.