NQL

The aim is putting together various nql related projects into single, easy to use api. It allows:
- parsing of NQL expression into Mongo JSON (using nql-lang)
- enhancing a database query with additional filters based on provided expression (using mongo-knex)
- querying JSON objects with NQL expressions (using mingo)

Installation

Using npm:
``


npm install @tryghost/nql --save


or with yarn:


yarn add @tryghost/nql


Example

A simple NQL expression could have following form:

featured:true+slug:['photo', 'video']


When parsing it to Mongo JSON with

nql(expression).parse()

 the output would be:

javascript
{
    $and: [
        {
            featured: true
        },
        {
            slug: {
                $in: ['photo', 'video']
            }
        }
    ]
}

If the same expression would be applied to Knex QueryBuilder object, the following SQL where statement would be generated:`sql where (posts.featured = true and posts.slugin ('photo', 'video'))`

`Usage`


Some common usages:

javascript
nql('id:3').toJSON();
\\ => {id:3}

`javascript nql('id:3').queryJSON({test:true, id:3}); \\ => true`

`javascript nql('tags:test', {expansions: {tags: 'tags.slug'}}).toJSON(); \\ => {'tags.slug': test}``javascript nql('primary_tag:[photo]', {expansions: [ {key: 'primary_tag', replacement: 'tags.slug', expansion: 'order:0'} ]}) \\ => {$and: [{'tags.slug': {$in: ['photo']}}, {order: 0}]}`

Advanced usage example:

`javascript // Builds SQL where statement on top of knex Query Builder including: // - combining custom filter 'primary_tag:test' with overrides filter and defaults // - expanding shortcut property 'primary_tag' into 'tags.slug' and adding 'posts_tags.sort_order:0' filter // - builds a where statement with relatedtagstable through manyToMany relation const query = nql('primary_tag:test', { relations: { tags: { tableName: 'tags', type: 'manyToMany', joinTable: 'posts_tags', joinFrom: 'post_id', joinTo: 'tag_id' } }, expansions: [ { key: 'primary_tag', replacement: 'tags.slug', expansion: 'posts_tags.sort_order:0' } ], overrides: 'status:published', defaults: 'featured:true' });

query .querySQL(knex('posts')) .select();`

`Test`

yarn lint

 run just eslint
-

yarn test` run lint && tests

Copyright & License

NQL