Javascript RQL


The javascript-rql is a simple and powerful library to transform javascript object to valid rql query string. Supports queries of any complexity (any nesting).

RQL

RQL (Resource query language) is designed for modern application development. It is built for the web, ready for NoSQL, and highly extensible with simple syntax.
This is a query language fast and convenient database interaction. RQL was designed for use in URLs to request object-style data structures.

RQL Reference

RQL for Web

Django RQL

Install

To install the javascript-rql from a terminal window type:

``sh
$ npm install --save javascript-rql
`

Interface

Javascript object with rql expressions should implement the following interface (typescript example):
`typescript
interface IRQLExpression {
$eq?: string|number,
$ne?: string|number,
$not?: IRQLExpression,
$gt?: number,
$ge?: number,
$lt?: number,
$le?: number,
$like?: string,
$ilike?: string,
$in?: Array,
$out?: Array,
$range?: {
min: number,
max: number,
},
}

interface IRQL {
$and? Array
$or?: Array;
$ordering?: Array;
$select?: Array;
limit?: number;
offset?: number;
[key: string]?: string|number|Array|boolean|IRQLExpression;
}
`


Usage


You can import rql function:
`js
import { rql } from 'javascript-rql';
`
or
`js
const { rql } = require('javascript-rql');
`

and use:
`js
rql(rqlObject);
`




Examples

##### Simple filters
`js
const filter = {
name: 'eugene',
age: 13,
};

rql(filter); // 'name=eugene&age=13'
`

##### Filters with text matching
`js
const filter = {
name: {
$like: 'vasya*',
$ilike: '*New',
},
city: {
$like: {
start: 'M',
end: 'w',
},
$ilike: {
start: 'M',
},
},
country: {
$like: {
end: 'a',
},
$ilike: {
pattern: 'uss*',
start: 'R',
end: 'a',
},
},
area: {
$ilike: true,
$like: {
invalidKey: 'qwe',
},
},
};

rql(filter); //'like(name,vasya\)&ilike(name,\\\New)&like(city,Mw)&ilike(city,M)&like(country,a)&ilike(country,Ra)&ilike(country,uss)like(name,vasya\)&ilike(name,\\\New)&like(city,Mw)&ilike(city,M)&like(country,a)&ilike(country,Ra)&ilike(country,uss)'
`

##### Filter with list
`js
const filter = {
age: {
$out: [1, 2],
},
num: {
$in: [3, 4, 5],
},
};

rql(filter); //'out(age,(1,2))&in(num,(3,4,5))'
`

##### Filters with range
`js
const filter = {
age: {
$range: {
max: 5,
min: 9,
},
},
};

rql(filter); //'range(age,9,5)'
`

##### Filters with relationals
`js
const filter = {
name: {
$eq: 'vasya',
},
age: {
$gt: 1,
$lt: 8,
},
num: {
$lte: 9,
$gte: 4,
},
};

rql(filter); //'eq(name,vasya)>(age,1)<(age,8)<e(num,9)>e(num,4)'
`

##### Filters with logical NOT
`js
const filter = {
name: {
$not: [{
$eq: 'vasya',
}, {
$eq: 'petya',
}],
},
age: {
$not: {
$eq: 10,
$in: [1, 2, 3],
},
},
};

rql(filter); //'not(eq(name,vasya))¬(eq(name,petya))¬(eq(age,10))¬(in(age,(1,2,3)))'
`

##### Filters with logical OR
`js
const filter = {
// You can use $or inside field
color: {
$or: [
// Inside { } may be some conditions and for all them is used logical operator AND
{ $eq: 'red' },
{ $eq: 'blue' },
{ $eq: 'yellow' },
],
},

// Also you can use $or in root level, then inside must be objects array with fields name
$or: [
// Inside { } may be some fields with conditions and for all them is used logical operator AND
{ product: 'TV' },
{ product: 'Computer' },
],
};

rql(filter); //'(((eq(color,red))|(eq(color,blue)))|(eq(color,yellow)))&((product=TV)|(product=Computer))'
`

##### Combine AND and OR filters
`js
// When you need to use same keys in and conditions (for example with OR) you can use special logical AND:
const filter = {
$and: [
{
$or: [
{status: 'new'},
{type: 'program'},
],
},
{
$or: [
{status: 'done'},
{type: 'service'},
]
},
]
};

rql(filter); // "(((status=new)|(type=program)))&(((status=done)|(type=service)))"
`

##### Filters with control operators
We support 2 key for ordering: ordering and sort. Use the one which is implemented by the backend.
`js
const filter = {
$select: ['products', 'agreements'],
$ordering: '-created',
$sort: ['-name'],
$limit: { start: 10, count: 100 },
};

rql(filter); //Result: 'select(products,agreements)&ordering(-created)&sort(-name)&limit(10,100)'
`

##### Combine any filters in one query
`js
const combinationFilter = {
offset: 0,
limit: 10,
$select: ['products', 'agreements'],
$ordering: ['title', '-created'],
$or: [
{
type: 'distribution',
owner: { $eq: 'me' },
},
{
type: { $in: ['sourcing', 'service'] },
owner: { $not: { $eq: 'me' } },
},
],
name: {
$or: [
{ $like: 'my test' },
{ $like: 'my' },
{ $ilike: '*CONTRACT' },
],
},
};

rql(filter); //'offset=0&limit=10&select(products,agreements)&ordering(title,-created)&((type=distribution&eq(owner,me))|(in(type,(sourcing,service))¬(eq(owner,me))))&(((like(name,"my test"))|(like(name,my)))|(ilike(name,\\\CONTRACT*)))'
`

##### Filters with empty values
`js
// If values are empty, null, undefined then they will not be in the query.
const filter = {
$select: [],
$ordering: [],
name: '',
age: null,
$or: [{name: undefined}],
type: 'pending',
};

rql(filter); //'type=pending'
``

Contribute

If you want to contribute to the javascript-rql development feel free to open issues or fork the github repository and submit your pull request.

License

The javascript-rql is licensed under the Apache License 2.0.