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.
Install
To install the javascript-rql from a terminal window type:
$ npm install --save javascript-rql
Interface
Javascript object with rql expressions should implement the following interface (typescript example):
interface IRQLExpression {
$eq?: string|number,
$ne?: string|number,
$not?: IRQLExpression,
$gt?: number,
$ge?: number,
$lt?: number,
$le?: number,
$like?: string,
$ilike?: string,
$in?: Array<number|string>,
$out?: Array<number|string>,
$range?: {
min: number,
max: number,
},
}
interface IRQL {
$and? Array<IRQL>
$or?: Array<IRQL>;
$ordering?: Array<string>;
$select?: Array<string>;
limit?: number;
offset?: number;
[key: string]?: string|number|Array<string|number>|boolean|IRQLExpression;
}
Usage
You can import rql function:
import { rql } from 'javascript-rql';
or
const { rql } = require('javascript-rql');
and use:
rql(rqlObject);
Examples
Simple filters
const filter = {
name: 'eugene',
age: 13,
};
rql(filter); // 'name=eugene&age=13'
Filters with text matching
const filter = {
name: {
$like: 'vasya*',
$ilike: '***New',
},
city: {
$like: {
start: 'M',
end: 'w',
},
$ilike: {
start: 'M',
},
},
country: {
$like: {
end: 'a',
},
$ilike: {
pattern: '*u*ss*',
start: 'R',
end: 'a',
},
},
area: {
$ilike: true,
$like: {
invalidKey: 'qwe',
},
},
};
rql(filter); //'like(name,*vasya\**)&ilike(name,*\*\*\*New*)&like(city,M*w)&ilike(city,M*)&like(country,*a)&ilike(country,R*a)&ilike(country,*u*ss*)like(name,*vasya\**)&ilike(name,*\*\*\*New*)&like(city,M*w)&ilike(city,M*)&like(country,*a)&ilike(country,R*a)&ilike(country,*u*ss*)'
Filter with list
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
const filter = {
age: {
$range: {
max: 5,
min: 9,
},
},
};
rql(filter); //'range(age,9,5)'
Filters with relationals
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
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
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
// 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.
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
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
// 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.