These examples illustrate how to build relationship filter queries.

The user may first issue a query for Editor records for an editor named Jane Smith who works in the city of Boston:

collection()/record
[
	editor_name = "Jane Smith"
	and 
	editor_city = "Boston"
]

The query is then modified for Author records:

collection()/record
[
	author_editorref = collection()/record
	[
		editor_name = "Jane Smith"
		and
		editor_city = "Boston"
	]
	/editor_id
]

The query returns all Author records filtered by the results of the Editor records. That is, the Author records are filtered by the editor_id property of the Editor records (which are referenced by the author_editorref property in the Author records).

The next example query returns books by American authors:

collection()/record
[
	book_authorref = collection()/record
	[
		author_nationality = "american"
	]
	/author_id
]

The next example query returns all books by authors who are still alive:

collection()/record
[
	book_authorref = collection()/record
	[
		author_deceased ="false"
	]
	/author_id
]

The next example query combines the two previous examples, and also illustrates the use of the or operator. Both inner collection()/record functions use the author_id property value results as indexes for the Book records.

collection()/record
[
	book_authorref = collection()/record
	[
		author_nationality = "american"
	]
	/author_id 
	or
	book_authorref = collection()/record
	[
		author_deceased="false"
	]
	/author_id
]

The next example query returns the books written by authors who have had those books published in a hard-cover format.

collection()/record
[
	book_authorref=collection()/record
	[
		author_bookref=collection()/record
		[
			book_cover = "hard"
		]
		/book_id
	]
	/author_id
]

The next query example extends the previous one by returning the books written by authors who have published hard-cover books and have worked with an editor named "Jane Smith". The query also shows how to apply relationship filters among all three record types.

collection()/record
[
	book_authorref=collection()/record
	[
		author_bookref=collection()/record
		[
			book_cover="hard"
		]
		/book_id 
		and 
		author_editorref=collection()/record
		[
			editor_name="Jane Smith"
		]
		/editor_id
	]
	/author_id
]

In the final example, this powerful query returns all books written by the author of a play titled "The Island Princess" (which was written by English playwright John Fletcher) and also all books that were written by authors who co-wrote books with Fletcher. The result set will include plays that were written either by Fletcher or by anyone who has ever co-authored a play with Fletcher.

collection()/record
[
	book_authorref = collection()/record
	[
		author_bookref = collection()/record
		[
			book_authorref = collection()/record
			[
				author_bookref = collection()/record
				[
					book_title = "The Island Princess"
				]
				/book_id
			]
			/author_id
		]
		/book_id
	]
	/author_id
]