Uniql NPM | npm.io

UniQL (UNIversal Query Language)

Lets you write a simple query and run it against any datastore, like ElasticSearch and/or MongoDB.

UniQL parses a simple query langauge into an Abstract Syntax Tree that can then be used to compile a query for a given datastore. This is useful if you want a level of abstraction between your queries and how your data is actually stored/searched. You can also use UniQL to execute the same query against multiple datastores at the same time.

For example:

const parse = require( 'uniql' );
const mongoCompile = require( 'uniql-mongodb' );
const esCompile = require( 'uniql-es' );

// parse a uniql query into an AST
const queryAST = parse( '( height <= 20 or ( favorites.color == "green" and height != 25 ) ) and firstname ~= "o.+"' );

// using that AST, compile a mongodb query
const mongoQuery = mongoCompile( queryAST );
console.log( util.inspect( mongoQuery, { depth: null } ) );

// using the same AST, compile an elasticsearch query
const esQuery = esCompile( queryAST );
console.log( util.inspect( esQuery, { depth: null } ) );

For MongoDB, the query generated is:

{ '$or':
   [ { height: { '$lte': 20 } },
     { 'favorites.color': 'green', height: { '$ne': 25 } } ],
  firstname: { '$regex': 'o.+' } }

For ElasticSearch, the same query is:

{ query:
   { filtered:
      { filter:
         [ { bool:
              { must:
                 [ { bool:
                      { should:
                         [ { range: { height: { lte: 20 } } },
                           { bool:
                              { must:
                                 [ { term: { 'favorites.color': 'green' } },
                                   { bool: { must_not: { term: { height: 25 } } } } ] } } ] } },
                   { bool: { must: { regexp: { firstname: 'o.+' } } } } ] } } ] } } }

All generated from one simple query:

( height <= 20 or ( favorites.color == "green" and height != 25 ) ) and firstname ~= "o.+"

Which produces the following AST:

{ type: '&&',
  arguments:
   [ { type: 'EXPRESSION',
       arguments:
        [ { type: '||',
            arguments:
             [ { type: '<=',
                 arguments:
                  [ { type: 'SYMBOL', arguments: [ 'height' ] },
                    { type: 'NUMBER', arguments: [ '20' ] } ] },
               { type: 'EXPRESSION',
                 arguments:
                  [ { type: '&&',
                      arguments:
                       [ { type: '==',
                           arguments:
                            [ { type: 'SYMBOL', arguments: [ 'favorites.color' ] },
                              { type: 'STRING', arguments: [ 'green' ] } ] },
                         { type: '!=',
                           arguments:
                            [ { type: 'SYMBOL', arguments: [ 'height' ] },
                              { type: 'NUMBER', arguments: [ '25' ] } ] } ] } ] } ] } ] },
     { type: 'MATCH',
       arguments:
        [ { type: 'SYMBOL', arguments: [ 'firstname' ] },
          { type: 'STRING', arguments: [ 'o.+' ] } ] } ] }

Using that AST, you can generate queries for various datastores.

Available Compilers

MongoDB
ElasticSearch
JavaScript
!! Your compiler here! Submissions welcome! !!

UniQL Query Syntax

Values	Description
43, -1.234	Numbers
true, false	Booleans
null, undefined	Primitives
"hello"	Strings
foo, a.b.c	Symbols (usually a key or column name in your datastore)

Operators	Description
x == y	Equality
x != y	Ineqaulity
x ~= "y"	Matching evaluated as a RegExp
x < y	Less than
x <= y	Less than or equal to
x > y	Greater than
x >= y	Greater than or equal to
x or y	Boolean or
x and y	Boolean and
not x	Boolean not
( x )	Expression