Querying: RQL - Raven Query Language

The following keywords and methods are available in RQL:

• DECLARE
• FROM
  • INDEX
• GROUP BY
  • array()
• WHERE
  • id()
  • search()
  • cmpxchg()
  • boost()
  • regex()
  • startsWith()
  • endsWith()
  • lucene()
  • exists()
  • exact()
  • intersect()
  • spatial.within()
  • spatial.contains()
  • spatial.disjoint()
  • spatial.intersects()
  • moreLikeThis()
• ORDER BY
  • ASC | ASCENDING
  • DESC | DESCEDING
  • AS
  • string
  • long
  • double
  • alphaNumeric
  • random()
  • score()
  • spatial.distance()
• LOAD
• SELECT
  • DISTINCT
  • key()
  • sum()
  • count()
  • facet()
• UPDATE
• INCLUDE
• WITH
• MATCH

With the following operators:

• >=
• <=
• <> or !=
• <
• >
• = or ==
• BETWEEN
• IN
• ALL IN
• OR
• AND
• NOT
• (
• )

And the following values:

• true
• false
• null
• string e.g. 'John' or "John"
• number (long and double) e.g. 17
• parameter e.g. $param1

The keyword declare gives you the ability to create a JS function that can be reused in select (when projection is done). You can read more about it here.

The keyword from is used to determine the source data that should be used when a query is executed. You have two options:

1. from <collection>

This option is used to perform:

• Collection queries that are doing basic ID filtering only, e.g. from Companies where id() == 'companies/1-A' where there is no need to query an index, we can return the document from the storage directly
• Dynamic queries that are being executed against Auto Index

1. from INDEX <index-name>

This option is used to perform RQL operations against a given [static index].

The keyword group by is used to create an aggregation query. Please refer to the article about dynamic group by queries to find out more.

The keyword where is used to filter-out the documents from final results.

Operator: >= <= <> != < > = ==

The operators above are considered basic and self-explanatory. They work on all value types including 'numbers' and 'strings'.

The simplest example would be to return results with the field value equal to a given input. If you want to return a document from the @companies collection (more about collection can be read here), you need to execute the following query:

from Companies
where Name = 'The Big Cheese'

Filtering on nested properties is also supported, so in order to return all companies from 'Albuquerque' we need to execute following query:

from Companies
where Address.City = 'Albuquerque'

Operator: BETWEEN

The operator between returns results inclusively, and the type of border values used must match. It works on both 'numbers' and 'strings' and can be substituted with the >= and <= operators (see the example below).

from Products 
where PricePerUnit between 10.5 and 13.0

or

from Products 
where PricePerUnit >= 10.5 and PricePerUnit <= 13.0

Operator: IN

The operator in is validating if a given field contains passed values. It will return results if a given field matches any of the passed values.

from Companies 
where Name IN ('The Big Cheese', 'Unknown company name')

from Orders 
where Lines[].ProductName in ('Chang', 'Spegesild', 'Unknown product name')

Operator: ALL IN

This operator checks if all passes values are matching a given field. Due to its mechanics, it is only useful when used on array fields.

The following query will yield no results in contrast to an 'in' operator.

from Orders 
where Lines[].ProductName all in ('Chang', 'Spegesild', 'Unknown product name')

but removing the 'Unknown product name' will give you orders that only contains products with both 'Chang' and 'Spegesild' names

from Orders 
where Lines[].ProductName all in ('Chang', 'Spegesild')

Binary operators: AND OR NOT

Binary operators can be used to build more complex statements. The NOT operator can only be used with one of the other binary operators creating OR NOT or AND NOT ones.

from Companies
where Name = 'The Big Cheese' OR Name = 'Richter Supermarkt'

from Orders
where Freight > 500 AND ShippedAt > '1998-01-01'

from Orders
where Freight > 500 AND ShippedAt > '1998-01-01' AND NOT Freight = 830.75

Subclauses: ( )

Subclauses can be used along with binary operators to build even more complex logical statements. They are self-explanatory so no example will be given.

To perform sorting, the order by must be used. If you are interested in this subject, please read our dedicated sorting article here.

When there is a need to use data from an external document in projection, load can be used. Please refer to the following projection article to find out more about it.

Projections can be performed by using select. Please read our dedicated projection article here.

To patch documents on the server-side, use update with the desired JS script that will be applied to any documents matching the query criteria. For more information, please refer to our patching article.

The keyword include has been introduced to support attaching additional documents to the query response. A dedicated article that tackles this subject can be found here.

The keyword with is used to determine the data source of a graph query.
There are two types of with clauses, regular with and with edges.

• with: with {from Orders} as o
  The above statment means that the data source refered to by the allias o is the resualt of the from Orders query

• with edges: with edges (Lines) { where Discount >= 0.25 select Product } as cheap
  The above statment means that our data source is the property Lines of the source documents and we filter all lines that match Discount >= 0.25 query the destination refered to by the cheap alias is the product pointed by the Product property of the order line

For more details regarding graph queries please read the following article about graph query

The keyword match is used to determine the pattern of a graph query.
match (Orders as o)-[Lines as cheap where Discount >= 0.25 select Product]->(Products as p)
The above statment means that we are searching for a pattern that starts with an order and traverse using the order lines refered to by the Lines property where their Discount property is larger than 25% and the destination is the product refered to by the Product property.

A match may contain an edge in both direction, a right edge would look like so (node1)-[right]->(node2) and a left one would look like so (node1)<-[left]-(node2).
Any combination of edges is allowed in a match clause e.g.
(node1)-[right]->(node2)<-[left]-(node3)
The above match will actually be translated to:
(node1)-[right]->(node2)
and
(node3)-[left]->(node2)
where the and is a set intersection between the two patterns.

For more details regarding graph queries please read the following article about graph query