FQL is a query language that allows you to retrieve, filter and project data from any data source containing FHIR Resources. It brings the power of three existing languages together: SQL, JSON and FhirPath. It allows you to create tables and is useful for gaining insight and perform quality control.
Invocations
URL: [base]/CodeSystem/$compose
URL: [base]/CodeSystem/[id]/$compose
Parameters (In)
| Name | Cardinality | Type | Documentation |
| system | 0..1 | Uri | The system in which composition is to be performed. This must be provided unless the operation is invoked on a code system instance |
| version | 0..1 | String | The version of the system for the inferencing to be performed |
| property | 0..* | One or more properties that contain information to be composed into the code | |
| property.code | 1..1 | Code | Identifies the property provided |
| property.value | 0..1 | Code | The value of the property provided |
| property.subproperty | 0..* | Nested Properties (mainly used for SNOMED CT composition, for relationship Groups) | |
| property.subproperty.code | 1..1 | Code | Identifies the sub-property provided |
| property.subproperty.value | 1..1 | Code | The value of the sub-property provided |
| exact | 1..1 | Boolean | Whether the operation is being used by a human, or a machine. If the operation is being used by a human, the terminology server can return a list of possible matches, with commentary. For a machine, the server returns sure matches, or none at all |
| compositional | 0..1 | Boolean | Post-coordinated expressions are allowed to be returned in the matching codes (mainly for SNOMED CT). Default = false |
Return Values (Out)
| Name | Cardinality | Type | Documentation |
| match | 0..* | Concepts returned by the server as a result of the inferencing operation | |
| match.code | 1..1 | Coding | A code that matches the properties provided |
| match.unmatched | 0..* | One or more properties that contain properties that could not be matched into the code | |
| match.unmatched.code | 1..1 | Code | Identifies the property provided |
| match.unmatched.value | 1..1 | Code | The value of the property provided |
| match.unmatched.property | 0..* | Nested Properties (mainly used for SNOMED CT composition, for relationship Groups) | |
| match.unmatched.property.code | 1..1 | Code | Identifies the sub-property provided |
| match.unmatched.property.value | 1..1 | Code | The value of the sub-property provided |
| match.comment | 0..1 | String | Information about the quality of the match, if operation is for a human |