AQL Parser

Abbreviated Query Language for generating data models (possibly for an ORM) and making writing select queries easier.

(Using jison as a parser generator.)

Install

npm install aql-parser

AQL Syntax

A basic introduction with corresponding SQL.

artist { name }         -> select artist.name from artist

artist { name, bio }    ->  select artist.name, artist.bio from artist

artist {
    name
    where name ilike 'pink %'
}
label on artist.id = artist_id {
    name as label_name
    order by name
}

select
    artist.name,
    label.name as label_name
from artist
left join label on artist.id = label.artist_id
where artist.name ilike 'pink %'
order by label.name

see test/sqlSpec in tests for more structure/usage.

JS Usage

Simple

var aql = require('aq-parser');

var statement = 'artist { name, count(*) as num_artists }';

var query = aql.parse(statement); // will be a Query object

query.getSQL(); // select artist.name, count(*) as num_artists from artist
query.getJSON(); // a JSON representation of the query object

// some data

query.getAliases(); // ['name', 'num_artists']
query.getFieldAliases(); // ['name']
query.getFieldInfo(); // { 'name' : 'artist.name' }

SQL Options

Table constraints:

// given the previous AQL statement and query object

var options = {
    constraints: ['active', 1] // field, val
};

query.getSQL(options);
// select artist.name, count(*) as num_artists from artist where artist.active = 1

// with joins
var statement = '\
    artist {\
        name\
    }\
    label on artist.id = artist_id {\
        name as label_name\
    }\
';

aql.parse(statement).getSQL(options);
// select artist.name, label.name as label_name
// from artist
// left join label on artist.id = label.artist_id and label.active = 1
// where artist.active = 1

Default fields:

var options = {
    constraints: ['active', 1]
  , fields: function(table) {
      return { id: table.name + '_id' };
    }
};

aql.parse(statement).getSQL(options);

Output:

select
  artist.id as artist_id,
  artist.name,
  label.id as label_id,
  label.name as label_name
from artist
left join label on artist.id = label.artist_id and label.active = 1
where artist.active = 1

A parser with options built in:

var options = {
    constraints: ['active', 1]
  , fields: function(table) {
      return { id: table.name + '_id' };
    }
};

var p = new aql.Parser(options)
  , parse = function(statement) { return p.parse(statement); };

Modifying the query with clauses:

// this uses the above parse function

var statement = '\
    artist {\
        name\
    }\
    label on artist.id = artist_id {\
        name as label_name\
    }\
';

var query = parse(statement);

query.getSQL({
    where: {
        id: 10
    }
});

Output:

select
  artist.id as artist_id,
  artist.name,
  label.id as label_id,
  label.name as label_name
from artist
left join label on artist.id = label.artist_id and label.active = 1
where
  artist.active = 1 and
  artist.id = 10

---

var clauses = {
  , limit: 10
  , offset: 20
};

query.getSQL(clauses);

Output:

select
  artist.id as artist_id,
  artist.name,
  label.id as label_id,
  label.name as label_name
from artist
left join label on artist.id = label.artist_id and label.active = 1
where
  artist.active = 1
limit 10
offset 20

See test/optionSpec for other ways of manipulating clauses.

Currently the only clauses supported are where|order_by|group_by|having|limit|offset.

Other Uses:

I'll get here eventually :)

Buildling the Parser

In the root project directory:

This will generate src/parser.js and report any conflicts

npm run-script gen-parser

This will generate the parser and run the tests.

Note: This overrides the current parser, so when changing the grammar, do this in another branch.

npm run-script build-test

To do:

• an option for Query.prototype.getSQL for implicit joins.

  query.getSQL({
    joinOn: function(table1, table2) {
      // if no join return false
      // else return string (table args are Table types)
      // this method would only get called if there is no join defined
    }
  });