QueryString Query Language

This repo holds an exploratory language not meant to be used in production. It was a learning exercise meant to practice defining a parsable query syntax that can be used in a query string of a url.

Goals

1. Be human readable in a URL (e.g. "http://www.example.com?query=prop1(lte(10)),prop2(lte(10))" )
2. Convert to a intermediate JavaScript data structure that can be adapted to another query api, such as MongoDB, or TypeOrm.

Structure

Expressions

Expressions a grouping of one or more operations on a property of a resource.

<Property>(<Operator>(<Value>))[,Expressions]

Properties

Properties are properties used to perform an operation. For example, given the /folders resource below, the available Properties are id, createdAt, ownerId, and name.

{
  "folders": [
    {
      "id": 0,
      "createdAt": "string",
      "ownerId": "string",
      "name": "string"
    }
  ],
  "pageData": { ... }
}

Expressions containing one or more unknown Properties result in a 400 Bad Request.

Operators

Operators determine the operation to apply when ing results.

Operator	Description	Example
,	and	prop1(lte(10)), prop2(lte(10))
between	between values	prop(between(1,10))
eq	equal to	prop(eq(10))
gt	greater than	prop(gt(10))
gte	greater than or equal to	prop(gte(10))
in	in array	prop(in('a', 'b', 'c'))
isNull	is null	prop(isNull())
lt	less than	prop(lt(100))
lte	less than or equal to	prop(lte(100))
not	not	prop(not(lte(100)))

Values

Values are values used to perform a operation. A Value can be of type string, number, boolean, ISODateString or a single dimension array of these types.

Type	Example
string	'string'
number	10, -10, 0.10
boolean	true, false
ISODateString	'2022-07-31T00:00:00.000Z'
array	'foo','bar', 1,2,3, '2022-07-31T00:00:00.000Z', '2022-08-31T00:00:00.000Z'