_filter

Aidbox offers the partial support of FHIR _filter API. However, we tend to use other search capabilities like AidboxQuery, SearchQuery, or Search resource for complex queries. They offer better expressiveness with SQL and better performance.

Supported operators

Operation	String	Number	Date	Token	Reference	Quantity
eq	+	+**	+	+*	n/a	+***
ne	-	+**	+	-	n/a	+***
co	+	-	-	n/a	n/a	n/a
sw	+	n/a	n/a	n/a	n/a	n/a
ew	+	n/a	n/a	n/a	n/a	n/a
gt/ge/lt/le	-	+	+	n/a	n/a	+***
po	n/a	n/a	-	n/a	n/a	n/a
ss	n/a	n/a	n/a	-	n/a	n/a
sb	n/a	n/a	n/a	-	n/a	n/a
in	n/a	n/a	n/a	-	n/a	n/a
re	n/a	n/a	n/a	n/a	-	n/a

* token search is case sensitive

** number search doesn't support implicit precision

*** support only numbers, not system with code

Chaining, dot expressions

Aidbox supports forward chained search parameters in _filter query and dot expressions.

Chained Parameters

. expressions

Examples

# returns patient with specific id
GET /fhir/Patient?_filter=id eq 'pt-2'

# returns patients with name that contain specific substring e.g. Smith
GET /fhir/Patient?_filter=name co 'smi'

# returns patients with address.city starting with provided string, e.g. London
GET /fhir/Patient?_filter=address-city sw 'Lon'

# returns all patients with birthdate >= (<=) provided date
GET /fhir/Patient?_filter=birthdate ge 1996-06-06
GET /fhir/Patient?_filter=birthdate le 1996-06-06

Logical expressions support

You can compose logical expressions using parentheses

GET /fhir/Patient?_filter=(name co 'smi' or name co 'fed') or name co 'unex'

Forward chains

Aidbox requires to specify chain targets explicitly:

GET /fhir/Patient?_filter=(organization:Organization.name eq 'myorg')

Dot expressions

GET /fhir/Patient?_filter=.name.0.family eq 'Doe'
GET /fhir/Patient?_filter=.name isnull true