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Generic JSON query object translation to multiple data backends

License: MIT License

CoffeeScript 99.67% JavaScript 0.33%

franca-js's Introduction

Franca-JS

This is a library meant to make it easy to get and view data from different backends. Queries are encoded in a common JSON format that can be translated for use with different data backend sources, such as Mongo or Solr.

Install

npm install franca-js

Usage

Quick example for making a Solr query, assuming solr-node-client is used.

franca = require 'franca-js'
solrClient = require 'configured-solr-client' # initialized solr-node-client

# This can be generated on the UI or passed in from another module
queryObj =
  options:
    limit: 20
  query:
    field: 'age'
    match: gt: 21

solrQuery = franca.toSolr queryObj

# prints q=age:([21 TO *] NOT 21)&rows=20
console.log solrQuery

solrClient.get 'query', solrQuery, (err, resp) ->
  # handle GET response

Overview

Franca queries are intended to be a common query format for the basic queries common to most data backends. Queries are separated into two parts, one being the core query which captures logic like and and or relationships, the other being the auxiliary options like number of rows to return. For SQL for instance, the core queries maps to the logic captured by the WHERE clause, while the auxiliary options would be everything else.

Of course, all data resources have their own quirks and special features, and no common query format can hope to capture all of these for each individual database. Franca queries support a raw mode that allow the user to pass a native query to the backend, exposing the full features of the underlying data resource.

API

Top level Franca API documentation is located here.

Common Query Format

The common query format is a JSON object that incorporates basics data query logic. See full documentation here.

Query Parser

(TODO)

The query parser translates from a string (for example, from a user typing into an input box) into the common JSON format.

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chen-factual

franca-js's Issues

Change on query object schema

When I'm implementing the write operation, I encountered some problems and thought that we may need change the query object schema:
0.) Since the write needs the type, query and option sometime, it's very confusing if we still allow type to be placed in the top level of query object. We should just put the type in the query, insert or update, they can specify the type just for query or write.
1.) To make the first level keys of query object to be clear, maybe we should put insert and update into a key called write.

Here is the proposed format after the changes:

{
  "query": {
    "type": "AND",
    "queries": []
  },
  "write": {
    "type": "RAW",
    "update": ""
  },
  "options": {
    "table": "test-table",
    "offset": 100,
    "singleRow": true
  }
}

@chen-factual what do you think about this?

Implement Update component

Implement Remove component

spec out insert / update format

Planning to add support for insert + update operations.

Does franca support `join` query? how hard is it to implement this lib using ruby?

Sometimes, we need to fetch data that are stored in multi tables, especially for relational database. Does franca-js support this kind of query?

Another question, is it hard to implement a similar lib using ruby?

Make match query support "null" value

For example:

query: {
  field: 'locality',
  match: ['Tucson', null]
}

should equals

query: {
   type: 'OR',
   queries: [
      {field: 'locality', match: ['Tucson']},
      {field: 'locality', null: true}
  ]
}

For match query contains negate=true

  query: {
    type: "AND",
    queries: [
      {field: 'locality', match: ['Tucson'], negate: true}
      {field: 'locality', null: false}
    ]
  }

Implement Insert component

Implement Write Operation

Based on what we spec in #4. Implement the insert, edit, and remove.

postgres: escape ' characters in match values

Currently getting this, which is not valid postgres syntax.

WHERE name = \'McDonald\'s\'

back to back translations trigger exception

TypeError: Object #<Object> has no method 'toSolr'
  at Object.module.exports [as toSolr] (/Users/chen/Code/franca-js/lib/translate/solr.coffee:10:27)
  at Object.<anonymous> (/Users/chen/Code/franca-js/test.coffee:43:12)
  at Object.<anonymous> (/Users/chen/Code/franca-js/test.coffee:1:1)
  at Module._compile (module.js:456:26)

The first toSolr call goes through, second one throws the above exception.