Fixed sorting with chunked and paged queries.

hapi-fhir-jpaserver-base/pom.xml

@@ -585,6 +585,11 @@
 			<version>1.0-SNAPSHOT</version>
 			<classifier>shaded6</classifier>
 		</dependency>
+		<dependency>
+			<groupId>org.postgresql</groupId>
+			<artifactId>postgresql</artifactId>
+			<version>42.2.9</version>
+		</dependency>
 
     </dependencies>
 

hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/dao/BaseHapiFhirResourceDaoObservation.java

@@ -21,7 +21,6 @@ package ca.uhn.fhir.jpa.dao;
  */
 
 import ca.uhn.fhir.jpa.api.dao.IFhirResourceDaoObservation;
-import ca.uhn.fhir.jpa.search.lastn.IndexConstants;
 import ca.uhn.fhir.jpa.searchparam.SearchParameterMap;
 import ca.uhn.fhir.rest.api.*;
 import ca.uhn.fhir.rest.api.server.*;
@@ -35,12 +34,18 @@ public abstract class BaseHapiFhirResourceDaoObservation<T extends IBaseResource
 		}
 
 		theSearchParameterMap.setLastN(true);
-		if (theSearchParameterMap.getSort() == null) {
+		SortSpec effectiveDtm = new SortSpec(getEffectiveParamName()).setOrder(SortOrderEnum.DESC);
-			SortSpec effectiveDtm = new SortSpec("date").setOrder(SortOrderEnum.DESC);
+		SortSpec observationCode = new SortSpec(getCodeParamName()).setOrder(SortOrderEnum.ASC).setChain(effectiveDtm);
-			// TODO: Should probably remove these constants, maybe move this logic to the version-specific classes.
+		if(theSearchParameterMap.containsKey(getSubjectParamName()) || theSearchParameterMap.containsKey(getPatientParamName())) {
-			SortSpec observationCode = new SortSpec(IndexConstants.CODE_SEARCH_PARAM).setOrder(SortOrderEnum.ASC).setChain(effectiveDtm);
+			theSearchParameterMap.setSort(new SortSpec(getSubjectParamName()).setOrder(SortOrderEnum.ASC).setChain(observationCode));
-			theSearchParameterMap.setSort(new SortSpec(IndexConstants.SUBJECT_SEARCH_PARAM).setOrder(SortOrderEnum.ASC).setChain(observationCode));
+		} else {
+			theSearchParameterMap.setSort(observationCode);
 		}
 	}
 
+	abstract protected String getEffectiveParamName();
+	abstract protected String getCodeParamName();
+	abstract protected String getSubjectParamName();
+	abstract protected String getPatientParamName();
+
 }

hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/dao/SearchBuilder.java

@@ -317,7 +317,7 @@ public class SearchBuilder implements ISearchBuilder {
 				} else {
 					throw new InvalidRequestException("Max parameter is required for $lastn operation");
 				}
-				List<String> lastnResourceIds = myIElasticsearchSvc.executeLastN(myParams, myMaxObservationsPerCode, theMaximumResults);
+				List<String> lastnResourceIds = myIElasticsearchSvc.executeLastN(myParams, myContext, theMaximumResults);
 				for (String lastnResourceId : lastnResourceIds) {
 					pids.add(myIdHelperService.resolveResourcePersistentIds(myRequestPartitionId, myResourceName, lastnResourceId));
 				}
@@ -422,52 +422,6 @@ public class SearchBuilder implements ISearchBuilder {
 			searchForIdsWithAndOr(myParams, theRequest);
 		}
 
-		/*
-		 * Fulltext or lastn search
-		 */
-/*		if (myParams.containsKey(Constants.PARAM_CONTENT) || myParams.containsKey(Constants.PARAM_TEXT) || myParams.isLastN()) {
-			List<ResourcePersistentId> pids = new ArrayList<>();
-			if (myParams.containsKey(Constants.PARAM_CONTENT) || myParams.containsKey(Constants.PARAM_TEXT)) {
-				if (myFulltextSearchSvc == null) {
-					if (myParams.containsKey(Constants.PARAM_TEXT)) {
-						throw new InvalidRequestException("Fulltext search is not enabled on this service, can not process parameter: " + Constants.PARAM_TEXT);
-					} else if (myParams.containsKey(Constants.PARAM_CONTENT)) {
-						throw new InvalidRequestException("Fulltext search is not enabled on this service, can not process parameter: " + Constants.PARAM_CONTENT);
-					}
-				}
-
-				if (myParams.getEverythingMode() != null) {
-					pids = myFulltextSearchSvc.everything(myResourceName, myParams, theRequest);
-				} else {
-					pids = myFulltextSearchSvc.search(myResourceName, myParams);
-				}
-			} else if (myParams.isLastN()) {
-				if (myIElasticsearchSvc == null) {
-					if (myParams.isLastN()) {
-						throw new InvalidRequestException("LastN operation is not enabled on this service, can not process this request");
-					}
-				}
-				Integer myMaxObservationsPerCode = null;
-				if(myParams.getLastNMax() != null) {
-					myMaxObservationsPerCode = myParams.getLastNMax();
-				} else {
-					throw new InvalidRequestException("Max parameter is required for $lastn operation");
-				}
-				List<String> lastnResourceIds = myIElasticsearchSvc.executeLastN(myParams, myMaxObservationsPerCode);
-				for (String lastnResourceId : lastnResourceIds) {
-					pids.add(myIdHelperService.resolveResourcePersistentIds(myRequestPartitionId, myResourceName, lastnResourceId));
-				}
-//				pids = normalizeIdListForLastNInClause(lastnResourceIds);
-			}
-			if (pids.isEmpty()) {
-				// Will never match
-				pids = Collections.singletonList(new ResourcePersistentId(-1L));
-			}
-
-			myQueryRoot.addPredicate(myQueryRoot.get("myId").as(Long.class).in(ResourcePersistentId.toLongList(pids)));
-
-		}
-*/
 		// Add PID list predicate for full text search and/or lastn operation
 		if (thePidList != null && thePidList.size() > 0) {
 			myQueryRoot.addPredicate(myQueryRoot.get("myId").as(Long.class).in(thePidList));

hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/dao/dstu3/FhirResourceDaoObservationDstu3.java

@@ -30,8 +30,6 @@ import ca.uhn.fhir.rest.api.Constants;
 import ca.uhn.fhir.rest.api.server.IBundleProvider;
 import ca.uhn.fhir.rest.api.server.RequestDetails;
 import ca.uhn.fhir.rest.api.server.storage.TransactionDetails;
-import ca.uhn.fhir.rest.param.ReferenceAndListParam;
-import ca.uhn.fhir.rest.param.TokenAndListParam;
 import org.hl7.fhir.instance.model.api.IBaseResource;
 import org.hl7.fhir.dstu3.model.Observation;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -52,6 +50,26 @@ public class FhirResourceDaoObservationDstu3 extends BaseHapiFhirResourceDaoObse
 		return mySearchCoordinatorSvc.registerSearch(this, theSearchParameterMap, getResourceName(), new CacheControlDirective().parse(theRequestDetails.getHeaders(Constants.HEADER_CACHE_CONTROL)), theRequestDetails);
 	}
 
+	@Override
+	protected String getEffectiveParamName() {
+		return Observation.SP_DATE;
+	}
+
+	@Override
+	protected String getCodeParamName() {
+		return Observation.SP_CODE;
+	}
+
+	@Override
+	protected String getSubjectParamName() {
+		return Observation.SP_SUBJECT;
+	}
+
+	@Override
+	protected String getPatientParamName() {
+		return Observation.SP_PATIENT;
+	}
+
 	@Override
 	public ResourceTable updateEntity(RequestDetails theRequest, IBaseResource theResource, IBasePersistedResource	theEntity, Date theDeletedTimestampOrNull, boolean thePerformIndexing,
 												 boolean theUpdateVersion, TransactionDetails theTransactionDetails, boolean theForceUpdate, boolean theCreateNewHistoryEntry) {

hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/dao/r4/FhirResourceDaoObservationR4.java

@@ -57,6 +57,26 @@ public class FhirResourceDaoObservationR4 extends BaseHapiFhirResourceDaoObserva
 		return mySearchCoordinatorSvc.registerSearch(this, theSearchParameterMap, getResourceName(), new CacheControlDirective().parse(theRequestDetails.getHeaders(Constants.HEADER_CACHE_CONTROL)), theRequestDetails);
 	}
 
+	@Override
+	protected String getEffectiveParamName() {
+		return Observation.SP_DATE;
+	}
+
+	@Override
+	protected String getCodeParamName() {
+		return Observation.SP_CODE;
+	}
+
+	@Override
+	protected String getSubjectParamName() {
+		return Observation.SP_SUBJECT;
+	}
+
+	@Override
+	protected String getPatientParamName() {
+		return Observation.SP_PATIENT;
+	}
+
 	@Override
 	public ResourceTable updateEntity(RequestDetails theRequest, IBaseResource theResource, IBasePersistedResource	theEntity, Date theDeletedTimestampOrNull, boolean thePerformIndexing,
 												 boolean theUpdateVersion, TransactionDetails theTransactionDetails, boolean theForceUpdate, boolean theCreateNewHistoryEntry) {

hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/dao/r5/FhirResourceDaoObservationR5.java

@@ -30,8 +30,6 @@ import ca.uhn.fhir.rest.api.Constants;
 import ca.uhn.fhir.rest.api.server.IBundleProvider;
 import ca.uhn.fhir.rest.api.server.RequestDetails;
 import ca.uhn.fhir.rest.api.server.storage.TransactionDetails;
-import ca.uhn.fhir.rest.param.ReferenceAndListParam;
-import ca.uhn.fhir.rest.param.TokenAndListParam;
 import org.hl7.fhir.instance.model.api.IBaseResource;
 import org.hl7.fhir.r5.model.Observation;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -52,6 +50,26 @@ public class FhirResourceDaoObservationR5 extends BaseHapiFhirResourceDaoObserva
 		return mySearchCoordinatorSvc.registerSearch(this, theSearchParameterMap, getResourceName(), new CacheControlDirective().parse(theRequestDetails.getHeaders(Constants.HEADER_CACHE_CONTROL)), theRequestDetails);
 	}
 
+	@Override
+	protected String getEffectiveParamName() {
+		return Observation.SP_DATE;
+	}
+
+	@Override
+	protected String getCodeParamName() {
+		return Observation.SP_CODE;
+	}
+
+	@Override
+	protected String getSubjectParamName() {
+		return Observation.SP_SUBJECT;
+	}
+
+	@Override
+	protected String getPatientParamName() {
+		return Observation.SP_PATIENT;
+	}
+
 	@Override
 	public ResourceTable updateEntity(RequestDetails theRequest, IBaseResource theResource, IBasePersistedResource	theEntity, Date theDeletedTimestampOrNull, boolean thePerformIndexing,
 												 boolean theUpdateVersion, TransactionDetails theTransactionDetails, boolean theForceUpdate, boolean theCreateNewHistoryEntry) {

hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/provider/dstu3/BaseJpaResourceProviderObservationDstu3.java

@@ -70,10 +70,7 @@ public class BaseJpaResourceProviderObservationDstu3 extends JpaResourceProvider
 
 		@Description(shortDefinition="The maximum number of observations to return for each observation code")
 		@OperationParam(name = "max", typeName = "integer", min = 0, max = 1)
-			IPrimitiveType<Integer> theMax,
+			IPrimitiveType<Integer> theMax
-
-		@Sort
-			SortSpec theSort
 
 	) {
 		startRequest(theServletRequest);
@@ -81,17 +78,17 @@ public class BaseJpaResourceProviderObservationDstu3 extends JpaResourceProvider
 			SearchParameterMap paramMap = new SearchParameterMap();
 			paramMap.add(Observation.SP_CATEGORY, theCategory);
 			paramMap.add(Observation.SP_CODE, theCode);
-			paramMap.add(Observation.SP_PATIENT, thePatient);
+			if (thePatient != null) {
-			paramMap.add(Observation.SP_SUBJECT, theSubject);
+				paramMap.add("patient", thePatient);
+			}
+			if (theSubject != null) {
+				paramMap.add("subject", theSubject);
+			}
 			paramMap.setLastNMax(theMax.getValue());
 			if (theCount != null) {
 				paramMap.setCount(theCount.getValue());
 			}
 
-			if (theSort != null) {
-				paramMap.setSort(theSort);
-			}
-
 			return ((IFhirResourceDaoObservation<Observation>) getDao()).observationsLastN(paramMap, theRequestDetails, theServletResponse);
 		} finally {
 			endRequest(theServletRequest);

hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/provider/r4/BaseJpaResourceProviderObservationR4.java

@@ -69,28 +69,25 @@ public class BaseJpaResourceProviderObservationR4 extends JpaResourceProviderR4<
 
 		@Description(shortDefinition="The maximum number of observations to return for each observation code")
 		@OperationParam(name = "max", typeName = "integer", min = 0, max = 1)
-			IPrimitiveType<Integer> theMax,
+			IPrimitiveType<Integer> theMax
-
-		@Sort
-			SortSpec theSort
 
 		) {
 		startRequest(theServletRequest);
 		try {
 			SearchParameterMap paramMap = new SearchParameterMap();
-			paramMap.add("category", theCategory);
+			paramMap.add(Observation.SP_CATEGORY, theCategory);
-			paramMap.add("code", theCode);
+			paramMap.add(Observation.SP_CODE, theCode);
-			paramMap.add("patient", thePatient);
+			if (thePatient != null) {
-			paramMap.add("subject", theSubject);
+				paramMap.add(Observation.SP_PATIENT, thePatient);
+			}
+			if (theSubject != null) {
+				paramMap.add(Observation.SP_SUBJECT, theSubject);
+			}
 			paramMap.setLastNMax(theMax.getValue());
 			if (theCount != null) {
 				paramMap.setCount(theCount.getValue());
 			}
 
-			if (theSort != null) {
-				paramMap.setSort(theSort);
-			}
-
 			return ((IFhirResourceDaoObservation<Observation>) getDao()).observationsLastN(paramMap, theRequestDetails, theServletResponse);
 		} finally {
 			endRequest(theServletRequest);

hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/provider/r5/BaseJpaResourceProviderObservationR5.java

@@ -70,28 +70,25 @@ public class BaseJpaResourceProviderObservationR5 extends JpaResourceProviderR5<
 
 		@Description(shortDefinition="The maximum number of observations to return for each observation code")
 		@OperationParam(name = "max", typeName = "integer", min = 0, max = 1)
-			IPrimitiveType<Integer> theMax,
+			IPrimitiveType<Integer> theMax
-
-		@Sort
-			SortSpec theSort
 
 	) {
 		startRequest(theServletRequest);
 		try {
 			SearchParameterMap paramMap = new SearchParameterMap();
-			paramMap.add("category", theCategory);
+			paramMap.add(Observation.SP_CATEGORY, theCategory);
-			paramMap.add("code", theCode);
+			paramMap.add(Observation.SP_CODE, theCode);
-			paramMap.add("patient", thePatient);
+			if (thePatient != null) {
-			paramMap.add("subject", theSubject);
+				paramMap.add(Observation.SP_PATIENT, thePatient);
+			}
+			if (theSubject != null) {
+				paramMap.add(Observation.SP_SUBJECT, theSubject);
+			}
 			paramMap.setLastNMax(theMax.getValue());
 			if (theCount != null) {
 				paramMap.setCount(theCount.getValue());
 			}
 
-			if (theSort != null) {
-				paramMap.setSort(theSort);
-			}
-
 			return ((IFhirResourceDaoObservation<Observation>) getDao()).observationsLastN(paramMap, theRequestDetails, theServletResponse);
 		} finally {
 			endRequest(theServletRequest);

hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/search/lastn/ElasticsearchSvcImpl.java

@@ -1,6 +1,8 @@
 package ca.uhn.fhir.jpa.search.lastn;
 
+import ca.uhn.fhir.context.FhirContext;
 import ca.uhn.fhir.jpa.searchparam.SearchParameterMap;
+import ca.uhn.fhir.jpa.searchparam.util.LastNParameterHelper;
 import ca.uhn.fhir.model.api.IQueryParameterType;
 import ca.uhn.fhir.rest.param.ReferenceParam;
 import ca.uhn.fhir.rest.param.TokenParam;
@@ -48,13 +50,18 @@ import static org.apache.commons.lang3.StringUtils.isBlank;
 
 public class ElasticsearchSvcImpl implements IElasticsearchSvc {
 
+	public static final String OBSERVATION_INDEX = "observation_index";
+	public static final String CODE_INDEX = "code_index";
+	public static final String OBSERVATION_DOCUMENT_TYPE = "ca.uhn.fhir.jpa.dao.lastn.entity.ObservationIndexedSearchParamLastNEntity";
+	public static final String CODE_DOCUMENT_TYPE = "ca.uhn.fhir.jpa.dao.lastn.entity.ObservationIndexedCodeCodeableConceptEntity";
+
 	private final RestHighLevelClient myRestHighLevelClient;
 
 	private final ObjectMapper objectMapper = new ObjectMapper();
 
 	private final String GROUP_BY_SUBJECT = "group_by_subject";
+	private final String GROUP_BY_SYSTEM = "group_by_system";
 	private final String GROUP_BY_CODE = "group_by_code";
-	private final String OBSERVATION_IDENTIFIER_FIELD_NAME = "identifier";
 
 
 	public ElasticsearchSvcImpl(String theHostname, int thePort, String theUsername, String thePassword) {
@@ -69,7 +76,7 @@ public class ElasticsearchSvcImpl implements IElasticsearchSvc {
 	}
 
 	private void createObservationIndexIfMissing() throws IOException {
-		if (indexExists(IndexConstants.OBSERVATION_INDEX)) {
+		if (indexExists(OBSERVATION_INDEX)) {
 			return;
 		}
 		String observationMapping = "{\n" +
@@ -124,14 +131,14 @@ public class ElasticsearchSvcImpl implements IElasticsearchSvc {
 			"    }\n" +
 			"  }\n" +
 			"}\n";
-		if (!createIndex(IndexConstants.OBSERVATION_INDEX, observationMapping)) {
+		if (!createIndex(OBSERVATION_INDEX, observationMapping)) {
 			throw new RuntimeException("Failed to create observation index");
 		}
 
 	}
 
 	private void createCodeIndexIfMissing() throws IOException {
-		if (indexExists(IndexConstants.CODE_INDEX)) {
+		if (indexExists(CODE_INDEX)) {
 			return;
 		}
 		String codeMapping = "{\n" +
@@ -161,7 +168,7 @@ public class ElasticsearchSvcImpl implements IElasticsearchSvc {
 			"    }\n" +
 			"  }\n" +
 			"}\n";
-		if (!createIndex(IndexConstants.CODE_INDEX, codeMapping)) {
+		if (!createIndex(CODE_INDEX, codeMapping)) {
 			throw new RuntimeException("Failed to create code index");
 		}
 
@@ -199,16 +206,18 @@ public class ElasticsearchSvcImpl implements IElasticsearchSvc {
 	}
 
 	@Override
-	// TODO: Should eliminate dependency on SearchParameterMap in API.
+	public List<String> executeLastN(SearchParameterMap theSearchParameterMap, FhirContext theFhirContext, Integer theMaxResultsToFetch) {
-	public List<String> executeLastN(SearchParameterMap theSearchParameterMap, Integer theMaxObservationsPerCode, Integer theMaxResultsToFetch) {
+		String OBSERVATION_IDENTIFIER_FIELD_NAME = "identifier";
 		String[] topHitsInclude = {OBSERVATION_IDENTIFIER_FIELD_NAME};
 		try {
-			List<SearchResponse> responses = buildAndExecuteSearch(theSearchParameterMap, theMaxObservationsPerCode, topHitsInclude);
+			List<SearchResponse> responses = buildAndExecuteSearch(theSearchParameterMap, theFhirContext, topHitsInclude);
 			List<String> observationIds = new ArrayList<>();
 			for (SearchResponse response : responses) {
-//				observationIds.addAll(buildObservationIdList(response));
+				Integer maxResultsToAdd = null;
-				Integer maxResultsToAdd = theMaxResultsToFetch - observationIds.size();
+				if (theMaxResultsToFetch != null) {
-				observationIds.addAll(buildObservationList(response, t -> t.getIdentifier(), theSearchParameterMap, maxResultsToAdd));
+					maxResultsToAdd = theMaxResultsToFetch - observationIds.size();
+				}
+				observationIds.addAll(buildObservationList(response, ObservationJson::getIdentifier, theSearchParameterMap, theFhirContext, maxResultsToAdd));
 			}
 			return observationIds;
 		} catch (IOException theE) {
@@ -216,23 +225,27 @@ public class ElasticsearchSvcImpl implements IElasticsearchSvc {
 		}
 	}
 
-	private List<SearchResponse> buildAndExecuteSearch(SearchParameterMap theSearchParameterMap, Integer theMaxObservationsPerCode,
+	private List<SearchResponse> buildAndExecuteSearch(SearchParameterMap theSearchParameterMap, FhirContext theFhirContext,
 																		String[] topHitsInclude) {
 		List<SearchResponse> responses = new ArrayList<>();
-		if (theSearchParameterMap.containsKey(IndexConstants.PATIENT_SEARCH_PARAM) || theSearchParameterMap.containsKey(IndexConstants.SUBJECT_SEARCH_PARAM)) {
+		String patientParamName = LastNParameterHelper.getPatientParamName(theFhirContext);
+		String subjectParamName = LastNParameterHelper.getSubjectParamName(theFhirContext);
+		if (theSearchParameterMap.containsKey(patientParamName)
+			|| theSearchParameterMap.containsKey(subjectParamName)) {
 			ArrayList<String> subjectReferenceCriteria = new ArrayList<>();
 			List<List<IQueryParameterType>> patientParams = new ArrayList<>();
-			if (theSearchParameterMap.get(IndexConstants.PATIENT_SEARCH_PARAM) != null) {
+			if (theSearchParameterMap.get(patientParamName) != null) {
-				patientParams.addAll(theSearchParameterMap.get(IndexConstants.PATIENT_SEARCH_PARAM));
+				patientParams.addAll(theSearchParameterMap.get(patientParamName));
 			}
-			if (theSearchParameterMap.get(IndexConstants.SUBJECT_SEARCH_PARAM) != null) {
+			if (theSearchParameterMap.get(subjectParamName) != null) {
-				patientParams.addAll(theSearchParameterMap.get(IndexConstants.SUBJECT_SEARCH_PARAM));
+				patientParams.addAll(theSearchParameterMap.get(subjectParamName));
 			}
 			for (List<? extends IQueryParameterType> nextSubjectList : patientParams) {
 				subjectReferenceCriteria.addAll(getReferenceValues(nextSubjectList));
 			}
 			for (String subject : subjectReferenceCriteria) {
-				SearchRequest myLastNRequest = buildObservationsSearchRequest(subject, theSearchParameterMap, createCompositeAggregationBuilder(theMaxObservationsPerCode, topHitsInclude));
+				SearchRequest myLastNRequest = buildObservationsSearchRequest(subject, theSearchParameterMap, theFhirContext,
+					createCompositeAggregationBuilder(theSearchParameterMap.getLastNMax(), topHitsInclude));
 				try {
 					SearchResponse lastnResponse = executeSearchRequest(myLastNRequest);
 					responses.add(lastnResponse);
@@ -241,7 +254,7 @@ public class ElasticsearchSvcImpl implements IElasticsearchSvc {
 				}
 			}
 		} else {
-			SearchRequest myLastNRequest = buildObservationsSearchRequest(theSearchParameterMap, createObservationCodeAggregationBuilder(theMaxObservationsPerCode, topHitsInclude));
+			SearchRequest myLastNRequest = buildObservationsSearchRequest(theSearchParameterMap, theFhirContext, createObservationCodeAggregationBuilder(theSearchParameterMap.getLastNMax(), topHitsInclude));
 			try {
 				SearchResponse lastnResponse = executeSearchRequest(myLastNRequest);
 				responses.add(lastnResponse);
@@ -254,13 +267,12 @@ public class ElasticsearchSvcImpl implements IElasticsearchSvc {
 	}
 
 	@VisibleForTesting
-	// TODO: Should eliminate dependency on SearchParameterMap in API.
+	List<ObservationJson> executeLastNWithAllFields(SearchParameterMap theSearchParameterMap, FhirContext theFhirContext) {
-	List<ObservationJson> executeLastNWithAllFields(SearchParameterMap theSearchParameterMap, Integer theMaxObservationsPerCode, Integer theMaxResultsToFetch) {
 		try {
-			List<SearchResponse> responses = buildAndExecuteSearch(theSearchParameterMap, theMaxObservationsPerCode, null);
+			List<SearchResponse> responses = buildAndExecuteSearch(theSearchParameterMap, theFhirContext, null);
 			List<ObservationJson> observationDocuments = new ArrayList<>();
 			for (SearchResponse response : responses) {
-				observationDocuments.addAll(buildObservationList(response, t -> t, theSearchParameterMap, theMaxResultsToFetch));
+				observationDocuments.addAll(buildObservationList(response, t -> t, theSearchParameterMap, theFhirContext, 100));
 			}
 			return observationDocuments;
 		} catch (IOException theE) {
@@ -269,20 +281,15 @@ public class ElasticsearchSvcImpl implements IElasticsearchSvc {
 	}
 
 	@VisibleForTesting
-	List<CodeJson> queryAllIndexedObservationCodes(int theMaxResultSetSize) throws IOException {
+	List<CodeJson> queryAllIndexedObservationCodes() throws IOException {
-		SearchRequest codeSearchRequest = buildObservationCodesSearchRequest(theMaxResultSetSize);
+		SearchRequest codeSearchRequest = new SearchRequest(CODE_INDEX);
-		SearchResponse codeSearchResponse = executeSearchRequest(codeSearchRequest);
-		return buildCodeResult(codeSearchResponse);
-	}
-
-	private SearchRequest buildObservationCodesSearchRequest(int theMaxResultSetSize) {
-		SearchRequest searchRequest = new SearchRequest(IndexConstants.CODE_INDEX);
 		SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
 		// Query
 		searchSourceBuilder.query(QueryBuilders.matchAllQuery());
-		searchSourceBuilder.size(theMaxResultSetSize);
+		searchSourceBuilder.size(1000);
-		searchRequest.source(searchSourceBuilder);
+		codeSearchRequest.source(searchSourceBuilder);
-		return searchRequest;
+		SearchResponse codeSearchResponse = executeSearchRequest(codeSearchRequest);
+		return buildCodeResult(codeSearchResponse);
 	}
 
 	private CompositeAggregationBuilder createCompositeAggregationBuilder(int theMaxNumberObservationsPerCode, String[] theTopHitsInclude) {
@@ -297,51 +304,27 @@ public class ElasticsearchSvcImpl implements IElasticsearchSvc {
 	}
 
 	private TermsAggregationBuilder createObservationCodeAggregationBuilder(int theMaxNumberObservationsPerCode, String[] theTopHitsInclude) {
-		TermsAggregationBuilder observationCodeAggregationBuilder = new TermsAggregationBuilder(GROUP_BY_CODE, ValueType.STRING).field("codeconceptid");
+		TermsAggregationBuilder observationCodeCodeAggregationBuilder = new TermsAggregationBuilder(GROUP_BY_CODE, ValueType.STRING).field("codeconceptcodingcode");
 		// Top Hits Aggregation
-		observationCodeAggregationBuilder.subAggregation(AggregationBuilders.topHits("most_recent_effective")
+		observationCodeCodeAggregationBuilder.subAggregation(AggregationBuilders.topHits("most_recent_effective")
 			.sort("effectivedtm", SortOrder.DESC)
 			.fetchSource(theTopHitsInclude, null).size(theMaxNumberObservationsPerCode));
-		observationCodeAggregationBuilder.size(10000);
+		observationCodeCodeAggregationBuilder.size(10000);
-		return observationCodeAggregationBuilder;
+		TermsAggregationBuilder observationCodeSystemAggregationBuilder = new TermsAggregationBuilder(GROUP_BY_SYSTEM, ValueType.STRING).field("codeconceptcodingsystem");
+		observationCodeSystemAggregationBuilder.subAggregation(observationCodeCodeAggregationBuilder);
+		return observationCodeSystemAggregationBuilder;
 	}
 
-	public SearchResponse executeSearchRequest(SearchRequest searchRequest) throws IOException {
+	private SearchResponse executeSearchRequest(SearchRequest searchRequest) throws IOException {
 		return myRestHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);
 	}
 
-	private List<String> buildObservationIdList(SearchResponse theSearchResponse) throws IOException {
-		List<String> theObservationList = new ArrayList<>();
-		for (ParsedComposite.ParsedBucket subjectBucket : getSubjectBuckets(theSearchResponse)) {
-			for (Terms.Bucket observationCodeBucket : getObservationCodeBuckets(subjectBucket)) {
-				for (SearchHit lastNMatch : getLastNMatches(observationCodeBucket)) {
-					String indexedObservation = lastNMatch.getSourceAsString();
-					ObservationJson observationJson = objectMapper.readValue(indexedObservation, ObservationJson.class);
-					theObservationList.add(observationJson.getIdentifier());
-				}
-			}
-		}
-		return theObservationList;
-	}
-
-	private List<ObservationJson> buildObservationDocumentList(SearchResponse theSearchResponse) throws IOException {
-		List<ObservationJson> theObservationList = new ArrayList<>();
-		for (ParsedComposite.ParsedBucket subjectBucket : getSubjectBuckets(theSearchResponse)) {
-			for (Terms.Bucket observationCodeBucket : getObservationCodeBuckets(subjectBucket)) {
-				for (SearchHit lastNMatch : getLastNMatches(observationCodeBucket)) {
-					String indexedObservation = lastNMatch.getSourceAsString();
-					ObservationJson observationJson = objectMapper.readValue(indexedObservation, ObservationJson.class);
-					theObservationList.add(observationJson);
-				}
-			}
-		}
-		return theObservationList;
-	}
-
 	private <T> List<T> buildObservationList(SearchResponse theSearchResponse, Function<ObservationJson,T> setValue,
-														  SearchParameterMap theSearchParameterMap, Integer theMaxResultsToFetch) throws IOException {
+														  SearchParameterMap theSearchParameterMap, FhirContext theFhirContext,
+														  Integer theMaxResultsToFetch) throws IOException {
 		List<T> theObservationList = new ArrayList<>();
-		if (theSearchParameterMap.containsKey(IndexConstants.PATIENT_SEARCH_PARAM) || theSearchParameterMap.containsKey(IndexConstants.SUBJECT_SEARCH_PARAM)) {
+		if (theSearchParameterMap.containsKey(LastNParameterHelper.getPatientParamName(theFhirContext))
+			|| theSearchParameterMap.containsKey(LastNParameterHelper.getSubjectParamName(theFhirContext))) {
 			for (ParsedComposite.ParsedBucket subjectBucket : getSubjectBuckets(theSearchResponse)) {
 				if (theMaxResultsToFetch != null && theObservationList.size() >= theMaxResultsToFetch) {
 					break;
@@ -387,14 +370,23 @@ public class ElasticsearchSvcImpl implements IElasticsearchSvc {
 
 	private List<? extends Terms.Bucket> getObservationCodeBuckets(SearchResponse theSearchResponse) {
 		Aggregations responseAggregations = theSearchResponse.getAggregations();
-		ParsedTerms aggregatedObservationCodes = responseAggregations.get(GROUP_BY_CODE);
+		return getObservationCodeBuckets(responseAggregations);
-		return aggregatedObservationCodes.getBuckets();
 	}
 
 	private List<? extends Terms.Bucket> getObservationCodeBuckets(ParsedComposite.ParsedBucket theSubjectBucket) {
-		Aggregations observationCodeAggregations = theSubjectBucket.getAggregations();
+		Aggregations observationCodeSystemAggregations = theSubjectBucket.getAggregations();
-		ParsedTerms aggregatedObservationCodes = observationCodeAggregations.get(GROUP_BY_CODE);
+		return getObservationCodeBuckets(observationCodeSystemAggregations);
-		return aggregatedObservationCodes.getBuckets();
+	}
+
+	private List<? extends Terms.Bucket> getObservationCodeBuckets(Aggregations theObservationCodeSystemAggregations) {
+		List<Terms.Bucket> retVal = new ArrayList<>();
+		ParsedTerms aggregatedObservationCodeSystems = theObservationCodeSystemAggregations.get(GROUP_BY_SYSTEM);
+		for(Terms.Bucket observationCodeSystem : aggregatedObservationCodeSystems.getBuckets()) {
+			Aggregations observationCodeCodeAggregations = observationCodeSystem.getAggregations();
+			ParsedTerms aggregatedObservationCodeCodes = observationCodeCodeAggregations.get(GROUP_BY_CODE);
+			retVal.addAll(aggregatedObservationCodeCodes.getBuckets());
+		}
+		return retVal;
 	}
 
 	private SearchHit[] getLastNMatches(Terms.Bucket theObservationCodeBucket) {
@@ -413,17 +405,16 @@ public class ElasticsearchSvcImpl implements IElasticsearchSvc {
 		return codes;
 	}
 
-	private SearchRequest buildObservationsSearchRequest(SearchParameterMap theSearchParameterMap, AggregationBuilder theAggregationBuilder) {
+	private SearchRequest buildObservationsSearchRequest(SearchParameterMap theSearchParameterMap, FhirContext theFhirContext, AggregationBuilder theAggregationBuilder) {
-		SearchRequest searchRequest = new SearchRequest(IndexConstants.OBSERVATION_INDEX);
+		SearchRequest searchRequest = new SearchRequest(OBSERVATION_INDEX);
 		SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
 		// Query
-		if (!searchParamsHaveLastNCriteria(theSearchParameterMap)) {
+		if (!searchParamsHaveLastNCriteria(theSearchParameterMap, theFhirContext)) {
 			searchSourceBuilder.query(QueryBuilders.matchAllQuery());
 		} else {
 			BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
-			addSubjectsCriteria(boolQueryBuilder, theSearchParameterMap);
+			addCategoriesCriteria(boolQueryBuilder, theSearchParameterMap, theFhirContext);
-			addCategoriesCriteria(boolQueryBuilder, theSearchParameterMap);
+			addObservationCodeCriteria(boolQueryBuilder, theSearchParameterMap, theFhirContext);
-			addObservationCodeCriteria(boolQueryBuilder, theSearchParameterMap);
 			searchSourceBuilder.query(boolQueryBuilder);
 		}
 		searchSourceBuilder.size(0);
@@ -435,14 +426,15 @@ public class ElasticsearchSvcImpl implements IElasticsearchSvc {
 		return searchRequest;
 	}
 
-	private SearchRequest buildObservationsSearchRequest(String theSubjectParam, SearchParameterMap theSearchParameterMap, AggregationBuilder theAggregationBuilder) {
+	private SearchRequest buildObservationsSearchRequest(String theSubjectParam, SearchParameterMap theSearchParameterMap, FhirContext theFhirContext,
-		SearchRequest searchRequest = new SearchRequest(IndexConstants.OBSERVATION_INDEX);
+																		  AggregationBuilder theAggregationBuilder) {
+		SearchRequest searchRequest = new SearchRequest(OBSERVATION_INDEX);
 		SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
 		// Query
 		BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
 		boolQueryBuilder.must(QueryBuilders.termQuery("subject", theSubjectParam));
-		addCategoriesCriteria(boolQueryBuilder, theSearchParameterMap);
+		addCategoriesCriteria(boolQueryBuilder, theSearchParameterMap, theFhirContext);
-		addObservationCodeCriteria(boolQueryBuilder, theSearchParameterMap);
+		addObservationCodeCriteria(boolQueryBuilder, theSearchParameterMap, theFhirContext);
 		searchSourceBuilder.query(boolQueryBuilder);
 		searchSourceBuilder.size(0);
 
@@ -453,30 +445,12 @@ public class ElasticsearchSvcImpl implements IElasticsearchSvc {
 		return searchRequest;
 	}
 
-	private Boolean searchParamsHaveLastNCriteria(SearchParameterMap theSearchParameterMap) {
+	private Boolean searchParamsHaveLastNCriteria(SearchParameterMap theSearchParameterMap, FhirContext theFhirContext) {
 		return theSearchParameterMap != null &&
-			(theSearchParameterMap.containsKey(IndexConstants.PATIENT_SEARCH_PARAM) || theSearchParameterMap.containsKey(IndexConstants.SUBJECT_SEARCH_PARAM) ||
+			(theSearchParameterMap.containsKey(LastNParameterHelper.getPatientParamName(theFhirContext))
-				theSearchParameterMap.containsKey(IndexConstants.CATEGORY_SEARCH_PARAM) || theSearchParameterMap.containsKey(IndexConstants.CODE_SEARCH_PARAM));
+				|| theSearchParameterMap.containsKey(LastNParameterHelper.getSubjectParamName(theFhirContext))
-	}
+				|| theSearchParameterMap.containsKey(LastNParameterHelper.getCategoryParamName(theFhirContext))
-
+				|| theSearchParameterMap.containsKey(LastNParameterHelper.getCodeParamName(theFhirContext)));
-	private void addSubjectsCriteria(BoolQueryBuilder theBoolQueryBuilder, SearchParameterMap theSearchParameterMap) {
-		if (theSearchParameterMap.containsKey(IndexConstants.PATIENT_SEARCH_PARAM) || theSearchParameterMap.containsKey(IndexConstants.SUBJECT_SEARCH_PARAM)) {
-			ArrayList<String> subjectReferenceCriteria = new ArrayList<>();
-			List<List<IQueryParameterType>> andOrParams = new ArrayList<>();
-			if (theSearchParameterMap.get(IndexConstants.PATIENT_SEARCH_PARAM) != null) {
-				andOrParams.addAll(theSearchParameterMap.get(IndexConstants.PATIENT_SEARCH_PARAM));
-			}
-			if (theSearchParameterMap.get(IndexConstants.SUBJECT_SEARCH_PARAM) != null) {
-				andOrParams.addAll(theSearchParameterMap.get(IndexConstants.SUBJECT_SEARCH_PARAM));
-			}
-			for (List<? extends IQueryParameterType> nextAnd : andOrParams) {
-				subjectReferenceCriteria.addAll(getReferenceValues(nextAnd));
-			}
-			if (subjectReferenceCriteria.size() > 0) {
-				theBoolQueryBuilder.must(QueryBuilders.termsQuery("subject", subjectReferenceCriteria));
-			}
-		}
-
 	}
 
 	private List<String> getReferenceValues(List<? extends IQueryParameterType> referenceParams) {
@@ -496,13 +470,14 @@ public class ElasticsearchSvcImpl implements IElasticsearchSvc {
 		return referenceList;
 	}
 
-	private void addCategoriesCriteria(BoolQueryBuilder theBoolQueryBuilder, SearchParameterMap theSearchParameterMap) {
+	private void addCategoriesCriteria(BoolQueryBuilder theBoolQueryBuilder, SearchParameterMap theSearchParameterMap, FhirContext theFhirContext) {
-		if (theSearchParameterMap.containsKey(IndexConstants.CATEGORY_SEARCH_PARAM)) {
+		String categoryParamName = LastNParameterHelper.getCategoryParamName(theFhirContext);
+		if (theSearchParameterMap.containsKey(categoryParamName)) {
 			ArrayList<String> codeSystemHashList = new ArrayList<>();
 			ArrayList<String> codeOnlyList = new ArrayList<>();
 			ArrayList<String> systemOnlyList = new ArrayList<>();
 			ArrayList<String> textOnlyList = new ArrayList<>();
-			List<List<IQueryParameterType>> andOrParams = theSearchParameterMap.get(IndexConstants.CATEGORY_SEARCH_PARAM);
+			List<List<IQueryParameterType>> andOrParams = theSearchParameterMap.get(categoryParamName);
 			for (List<? extends IQueryParameterType> nextAnd : andOrParams) {
 				codeSystemHashList.addAll(getCodingCodeSystemValues(nextAnd));
 				codeOnlyList.addAll(getCodingCodeOnlyValues(nextAnd));
@@ -593,13 +568,14 @@ public class ElasticsearchSvcImpl implements IElasticsearchSvc {
 		return textOnlyList;
 	}
 
-	private void addObservationCodeCriteria(BoolQueryBuilder theBoolQueryBuilder, SearchParameterMap theSearchParameterMap) {
+	private void addObservationCodeCriteria(BoolQueryBuilder theBoolQueryBuilder, SearchParameterMap theSearchParameterMap, FhirContext theFhirContext) {
-		if (theSearchParameterMap.containsKey(IndexConstants.CODE_SEARCH_PARAM)) {
+		String codeParamName = LastNParameterHelper.getCodeParamName(theFhirContext);
+		if (theSearchParameterMap.containsKey(codeParamName)) {
 			ArrayList<String> codeSystemHashList = new ArrayList<>();
 			ArrayList<String> codeOnlyList = new ArrayList<>();
 			ArrayList<String> systemOnlyList = new ArrayList<>();
 			ArrayList<String> textOnlyList = new ArrayList<>();
-			List<List<IQueryParameterType>> andOrParams = theSearchParameterMap.get(IndexConstants.CODE_SEARCH_PARAM);
+			List<List<IQueryParameterType>> andOrParams = theSearchParameterMap.get(codeParamName);
 			for (List<? extends IQueryParameterType> nextAnd : andOrParams) {
 				codeSystemHashList.addAll(getCodingCodeSystemValues(nextAnd));
 				codeOnlyList.addAll(getCodingCodeOnlyValues(nextAnd));
@@ -634,12 +610,4 @@ public class ElasticsearchSvcImpl implements IElasticsearchSvc {
 		myRestHighLevelClient.deleteByQuery(deleteByQueryRequest, RequestOptions.DEFAULT);
 	}
 
-/*	public void deleteObservationIndex(String theObservationIdentifier) throws IOException {
-		DeleteByQueryRequest deleteByQueryRequest = new DeleteByQueryRequest(IndexConstants.OBSERVATION_DOCUMENT_TYPE);
-		BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
-		boolQueryBuilder.must(QueryBuilders.termsQuery(OBSERVATION_IDENTIFIER_FIELD_NAME, theObservationIdentifier));
-		deleteByQueryRequest.setQuery(boolQueryBuilder);
-		myRestHighLevelClient.deleteByQuery(deleteByQueryRequest, RequestOptions.DEFAULT);
-	}
- */
 }

hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/search/lastn/IElasticsearchSvc.java

@@ -1,9 +1,10 @@
 package ca.uhn.fhir.jpa.search.lastn;
 
+import ca.uhn.fhir.context.FhirContext;
 import ca.uhn.fhir.jpa.searchparam.SearchParameterMap;
 
 import java.util.List;
 
 public interface IElasticsearchSvc {
-	List<String> executeLastN(SearchParameterMap theSearchParameterMap, Integer theMaxObservationsPerCode, Integer theMaxResultsToFetch);
+	List<String> executeLastN(SearchParameterMap theSearchParameterMap, FhirContext theFhirContext, Integer theMaxResultsToFetch);
 }

hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/search/lastn/IndexConstants.java

@@ -1,16 +0,0 @@
-package ca.uhn.fhir.jpa.search.lastn;
-
-public class IndexConstants {
-
-	// TODO: These should all be moved into ElasticSearchSvcImpl.
-	public static final String OBSERVATION_INDEX = "observation_index";
-	public static final String CODE_INDEX = "code_index";
-	public static final String OBSERVATION_DOCUMENT_TYPE = "ca.uhn.fhir.jpa.dao.lastn.entity.ObservationIndexedSearchParamLastNEntity";
-	public static final String CODE_DOCUMENT_TYPE = "ca.uhn.fhir.jpa.dao.lastn.entity.ObservationIndexedCodeCodeableConceptEntity";
-
-	public static final String SUBJECT_SEARCH_PARAM = "subject";
-	public static final String PATIENT_SEARCH_PARAM = "patient";
-	public static final String CODE_SEARCH_PARAM = "code";
-	public static final String CATEGORY_SEARCH_PARAM = "category";
-
-}

hapi-fhir-jpaserver-base/src/test/java/ca/uhn/fhir/jpa/config/TestR4Config.java

@@ -104,12 +104,12 @@ public class TestR4Config extends BaseJavaConfigR4 {
 		retVal.setDriver(new org.h2.Driver());
 //		retVal.setDriver(new org.postgresql.Driver());
 		retVal.setUrl("jdbc:h2:mem:testdb_r4");
-//		retVal.setUrl("jdbc:postgresql://localhost:5432/hapi");
+//		retVal.setUrl("jdbc:postgresql://localhost:5432/cdr");
 		retVal.setMaxWaitMillis(10000);
 		retVal.setUsername("");
-//		retVal.setUsername("hapi");
+//		retVal.setUsername("cdr");
 		retVal.setPassword("");
-//		retVal.setPassword("HapiFHIR");
+//		retVal.setPassword("SmileCDR");
 		retVal.setMaxTotal(ourMaxThreads);
 
 		SLF4JLogLevel level = SLF4JLogLevel.INFO;

hapi-fhir-jpaserver-base/src/test/java/ca/uhn/fhir/jpa/dao/r4/PersistObservationIndexedSearchParamLastNR4IT.java

@@ -60,6 +60,9 @@ public class PersistObservationIndexedSearchParamLastNR4IT {
 	@Autowired
 	ObservationLastNIndexPersistSvc testObservationPersist;
 
+	@Autowired
+	protected FhirContext myFhirCtx;
+
 	@Before
 	public void before() {
 
@@ -106,8 +109,9 @@ public class PersistObservationIndexedSearchParamLastNR4IT {
 		searchParameterMap.add(Observation.SP_CATEGORY, new TokenAndListParam().addAnd(new TokenOrListParam().addOr(categoryParam)));
 		TokenParam codeParam = new TokenParam(CODEFIRSTCODINGSYSTEM, CODEFIRSTCODINGCODE);
 		searchParameterMap.add(Observation.SP_CODE, new TokenAndListParam().addAnd(new TokenOrListParam().addOr(codeParam)));
+		searchParameterMap.setLastNMax(3);
 
-		List<String> observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap, 3, 100);
+		List<String> observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap, myFhirCtx, 100);
 
 		assertEquals(1, observationIdsOnly.size());
 		assertEquals(SINGLE_OBSERVATION_PID, observationIdsOnly.get(0));
@@ -180,15 +184,18 @@ public class PersistObservationIndexedSearchParamLastNR4IT {
 		// Check that all observations were indexed.
 		SearchParameterMap searchParameterMap = new SearchParameterMap();
 		searchParameterMap.add(Observation.SP_SUBJECT, multiSubjectParams);
-		//searchParameterMap.
+
-		List<String> observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap, 10, 200);
+		searchParameterMap.setLastNMax(10);
+
+		List<String> observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap, myFhirCtx, 200);
 		assertEquals(100, observationIdsOnly.size());
 
 		// Filter the results by category code.
 		TokenParam categoryParam = new TokenParam(CATEGORYFIRSTCODINGSYSTEM, FIRSTCATEGORYFIRSTCODINGCODE);
 		searchParameterMap.add(Observation.SP_CATEGORY, new TokenAndListParam().addAnd(new TokenOrListParam().addOr(categoryParam)));
 
-		observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap, 10, 100);
+
+		observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap, myFhirCtx, 100);
 
 		assertEquals(50, observationIdsOnly.size());
 
@@ -277,7 +284,8 @@ public class PersistObservationIndexedSearchParamLastNR4IT {
 
 		SearchParameterMap searchParameterMap = new SearchParameterMap();
 		searchParameterMap.add(Observation.SP_SUBJECT, multiSubjectParams);
-		List<String> observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap, 10, 200);
+		searchParameterMap.setLastNMax(10);
+		List<String> observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap, myFhirCtx, 200);
 		assertEquals(100, observationIdsOnly.size());
 		assertTrue(observationIdsOnly.contains("55"));
 
@@ -295,7 +303,7 @@ public class PersistObservationIndexedSearchParamLastNR4IT {
 		observation = myResourceIndexedObservationLastNDao.findForIdentifier("55");
 		assertNull(observation);
 
-		observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap, 10, 200);
+		observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap, myFhirCtx, 200);
 		assertEquals(99, observationIdsOnly.size());
 		assertTrue(!observationIdsOnly.contains("55"));
 
@@ -316,7 +324,9 @@ public class PersistObservationIndexedSearchParamLastNR4IT {
 		searchParameterMap.add(Observation.SP_CATEGORY, new TokenAndListParam().addAnd(new TokenOrListParam().addOr(categoryParam)));
 		TokenParam codeParam = new TokenParam(CODEFIRSTCODINGSYSTEM, CODEFIRSTCODINGCODE);
 		searchParameterMap.add(Observation.SP_CODE, new TokenAndListParam().addAnd(new TokenOrListParam().addOr(codeParam)));
-		List<String> observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap, 10, 200);
+		searchParameterMap.setLastNMax(10);
+
+		List<String> observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap, myFhirCtx, 200);
 		assertEquals(1, observationIdsOnly.size());
 		assertTrue(observationIdsOnly.contains(SINGLE_OBSERVATION_PID));
 
@@ -339,7 +349,7 @@ public class PersistObservationIndexedSearchParamLastNR4IT {
 		assertEquals(newEffectiveDtm.getValue(), updatedObservationEntity.getEffectiveDtm());
 
 		// Repeat earlier Elasticsearch query. This time, should return no matches.
-		observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap, 10, 200);
+		observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap, myFhirCtx, 200);
 		assertEquals(0, observationIdsOnly.size());
 
 		// Try again with the new patient ID.
@@ -348,7 +358,8 @@ public class PersistObservationIndexedSearchParamLastNR4IT {
 		searchParameterMap.add(Observation.SP_SUBJECT, new ReferenceAndListParam().addAnd(new ReferenceOrListParam().addOr(subjectParam)));
 		searchParameterMap.add(Observation.SP_CATEGORY, new TokenAndListParam().addAnd(new TokenOrListParam().addOr(categoryParam)));
 		searchParameterMap.add(Observation.SP_CODE, new TokenAndListParam().addAnd(new TokenOrListParam().addOr(codeParam)));
-		observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap, 10, 200);
+		searchParameterMap.setLastNMax(10);
+		observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap, myFhirCtx, 200);
 
 		// Should see the observation returned now.
 		assertEquals(1, observationIdsOnly.size());
@@ -398,11 +409,13 @@ public class PersistObservationIndexedSearchParamLastNR4IT {
 		SearchParameterMap searchParameterMap = new SearchParameterMap();
 
 		// execute Observation ID search - Composite Aggregation
-		List<String>  observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap,1, 200);
+		searchParameterMap.setLastNMax(1);
+		List<String>  observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap,myFhirCtx, 200);
 
 		assertEquals(20, observationIdsOnly.size());
 
-		observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap, 3, 200);
+		searchParameterMap.setLastNMax(3);
+		observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap, myFhirCtx, 200);
 
 		assertEquals(38, observationIdsOnly.size());
 

hapi-fhir-jpaserver-base/src/test/java/ca/uhn/fhir/jpa/search/lastn/LastNElasticsearchSvcMultipleObservationsIT.java

@@ -1,5 +1,6 @@
 package ca.uhn.fhir.jpa.search.lastn;
 
+import ca.uhn.fhir.context.FhirContext;
 import ca.uhn.fhir.jpa.searchparam.SearchParameterMap;
 import ca.uhn.fhir.rest.param.*;
 import ca.uhn.fhir.jpa.search.lastn.config.TestElasticsearchConfig;
@@ -21,7 +22,6 @@ import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 import java.io.IOException;
 import java.util.*;
 
-import static ca.uhn.fhir.jpa.search.lastn.IndexConstants.*;
 import static org.junit.Assert.*;
 
 @RunWith(SpringJUnit4ClassRunner.class)
@@ -35,6 +35,8 @@ public class LastNElasticsearchSvcMultipleObservationsIT {
 
 	private final Map<String, Map<String, List<Date>>> createdPatientObservationMap = new HashMap<>();
 
+	private FhirContext myFhirContext = FhirContext.forR4();
+
 
 	@BeforeClass
 	public static void beforeClass() {
@@ -51,8 +53,8 @@ public class LastNElasticsearchSvcMultipleObservationsIT {
 
 	@After
 	public void after() throws IOException {
-		elasticsearchSvc.deleteAllDocuments(OBSERVATION_INDEX);
+		elasticsearchSvc.deleteAllDocuments(ElasticsearchSvcImpl.OBSERVATION_INDEX);
-		elasticsearchSvc.deleteAllDocuments(CODE_INDEX);
+		elasticsearchSvc.deleteAllDocuments(ElasticsearchSvcImpl.CODE_INDEX);
 	}
 
 	@Test
@@ -80,8 +82,9 @@ public class LastNElasticsearchSvcMultipleObservationsIT {
 		searchParameterMap.add(Observation.SP_SUBJECT, buildReferenceAndListParam(subjectParam));
 		subjectParam = new ReferenceParam("Patient", "", "9");
 		searchParameterMap.add(Observation.SP_SUBJECT, buildReferenceAndListParam(subjectParam));
+		searchParameterMap.setLastNMax(3);
 
-		List<ObservationJson> observations = elasticsearchSvc.executeLastNWithAllFields(searchParameterMap, 3, 100);
+		List<ObservationJson> observations = elasticsearchSvc.executeLastNWithAllFields(searchParameterMap, myFhirContext);
 
 		assertEquals(60, observations.size());
 
@@ -152,8 +155,9 @@ public class LastNElasticsearchSvcMultipleObservationsIT {
 		TokenParam codeParam1 = new TokenParam("http://mycodes.org/fhir/observation-code", "test-code-1");
 		TokenParam codeParam2 = new TokenParam("http://mycodes.org/fhir/observation-code", "test-code-2");
 		searchParameterMap.add(Observation.SP_CODE, buildTokenAndListParam(codeParam1, codeParam2));
+		searchParameterMap.setLastNMax(100);
 
-		List<String> observations = elasticsearchSvc.executeLastN(searchParameterMap, 100, 100);
+		List<String> observations = elasticsearchSvc.executeLastN(searchParameterMap, myFhirContext, 100);
 
 		assertEquals(20, observations.size());
 
@@ -164,8 +168,9 @@ public class LastNElasticsearchSvcMultipleObservationsIT {
 		searchParameterMap.add(Observation.SP_PATIENT, buildReferenceAndListParam(patientParam1, patientParam2));
 		searchParameterMap.add(Observation.SP_CATEGORY, buildTokenAndListParam(categoryParam1, categoryParam2));
 		searchParameterMap.add(Observation.SP_CODE, buildTokenAndListParam(codeParam1, codeParam2));
+		searchParameterMap.setLastNMax(100);
 
-		observations = elasticsearchSvc.executeLastN(searchParameterMap, 100, 100);
+		observations = elasticsearchSvc.executeLastN(searchParameterMap, myFhirContext, 100);
 
 		assertEquals(20, observations.size());
 
@@ -197,8 +202,9 @@ public class LastNElasticsearchSvcMultipleObservationsIT {
 		searchParameterMap.add(Observation.SP_CATEGORY, buildTokenAndListParam(categoryParam));
 		TokenParam codeParam = new TokenParam("test-code-1");
 		searchParameterMap.add(Observation.SP_CODE, buildTokenAndListParam(codeParam));
+		searchParameterMap.setLastNMax(100);
 
-		List<String> observations = elasticsearchSvc.executeLastN(searchParameterMap, 100, 100);
+		List<String> observations = elasticsearchSvc.executeLastN(searchParameterMap, myFhirContext, 100);
 
 		assertEquals(5, observations.size());
 
@@ -214,8 +220,9 @@ public class LastNElasticsearchSvcMultipleObservationsIT {
 		searchParameterMap.add(Observation.SP_CATEGORY, buildTokenAndListParam(categoryParam));
 		TokenParam codeParam = new TokenParam("http://mycodes.org/fhir/observation-code", null);
 		searchParameterMap.add(Observation.SP_CODE, buildTokenAndListParam(codeParam));
+		searchParameterMap.setLastNMax(100);
 
-		List<String> observations = elasticsearchSvc.executeLastN(searchParameterMap, 100, 100);
+		List<String> observations = elasticsearchSvc.executeLastN(searchParameterMap, myFhirContext, 100);
 
 		assertEquals(10, observations.size());
 	}
@@ -231,8 +238,9 @@ public class LastNElasticsearchSvcMultipleObservationsIT {
 		TokenParam codeParam = new TokenParam("test-code-1 display");
 		codeParam.setModifier(TokenParamModifier.TEXT);
 		searchParameterMap.add(Observation.SP_CODE, buildTokenAndListParam(codeParam));
+		searchParameterMap.setLastNMax(100);
 
-		List<String> observations = elasticsearchSvc.executeLastN(searchParameterMap, 100, 100);
+		List<String> observations = elasticsearchSvc.executeLastN(searchParameterMap, myFhirContext, 100);
 
 		assertEquals(5, observations.size());
 
@@ -248,7 +256,9 @@ public class LastNElasticsearchSvcMultipleObservationsIT {
 		searchParameterMap.add(Observation.SP_CATEGORY, buildTokenAndListParam(categoryParam));
 		TokenParam codeParam = new TokenParam("http://mycodes.org/fhir/observation-code", "test-code-1");
 		searchParameterMap.add(Observation.SP_CODE, buildTokenAndListParam(codeParam));
-		List<String> observations = elasticsearchSvc.executeLastN(searchParameterMap, 100, 100);
+		searchParameterMap.setLastNMax(100);
+
+		List<String> observations = elasticsearchSvc.executeLastN(searchParameterMap, myFhirContext, 100);
 		assertEquals(0, observations.size());
 
 		// Invalid subject
@@ -259,7 +269,9 @@ public class LastNElasticsearchSvcMultipleObservationsIT {
 		searchParameterMap.add(Observation.SP_CATEGORY, buildTokenAndListParam(categoryParam));
 		codeParam = new TokenParam("http://mycodes.org/fhir/observation-code", "test-code-1");
 		searchParameterMap.add(Observation.SP_CODE, buildTokenAndListParam(codeParam));
-		observations = elasticsearchSvc.executeLastN(searchParameterMap, 100, 100);
+		searchParameterMap.setLastNMax(100);
+
+		observations = elasticsearchSvc.executeLastN(searchParameterMap, myFhirContext, 100);
 		assertEquals(0, observations.size());
 
 		// Invalid observation code
@@ -270,7 +282,9 @@ public class LastNElasticsearchSvcMultipleObservationsIT {
 		searchParameterMap.add(Observation.SP_CATEGORY, buildTokenAndListParam(categoryParam));
 		codeParam = new TokenParam("http://mycodes.org/fhir/observation-code", "test-code-999");
 		searchParameterMap.add(Observation.SP_CODE, buildTokenAndListParam(codeParam));
-		observations = elasticsearchSvc.executeLastN(searchParameterMap, 100, 100);
+		searchParameterMap.setLastNMax(100);
+
+		observations = elasticsearchSvc.executeLastN(searchParameterMap, myFhirContext, 100);
 		assertEquals(0, observations.size());
 
 		// Invalid category code
@@ -281,7 +295,9 @@ public class LastNElasticsearchSvcMultipleObservationsIT {
 		searchParameterMap.add(Observation.SP_CATEGORY, buildTokenAndListParam(categoryParam));
 		codeParam = new TokenParam("http://mycodes.org/fhir/observation-code", "test-code-1");
 		searchParameterMap.add(Observation.SP_CODE, buildTokenAndListParam(codeParam));
-		observations = elasticsearchSvc.executeLastN(searchParameterMap, 100, 100);
+		searchParameterMap.setLastNMax(100);
+
+		observations = elasticsearchSvc.executeLastN(searchParameterMap, myFhirContext, 100);
 		assertEquals(0, observations.size());
 
 	}
@@ -341,12 +357,12 @@ public class LastNElasticsearchSvcMultipleObservationsIT {
 					observationJson.setCategories(categoryConcepts1);
 					observationJson.setCode(codeableConceptField1);
 					observationJson.setCode_concept_id(codeableConceptId1);
-					assertTrue(elasticsearchSvc.performIndex(CODE_INDEX, codeableConceptId1, codeJson1Document, CODE_DOCUMENT_TYPE));
+					assertTrue(elasticsearchSvc.performIndex(ElasticsearchSvcImpl.CODE_INDEX, codeableConceptId1, codeJson1Document, ElasticsearchSvcImpl.CODE_DOCUMENT_TYPE));
 				} else {
 					observationJson.setCategories(categoryConcepts2);
 					observationJson.setCode(codeableConceptField2);
 					observationJson.setCode_concept_id(codeableConceptId2);
-					assertTrue(elasticsearchSvc.performIndex(CODE_INDEX, codeableConceptId2, codeJson2Document, CODE_DOCUMENT_TYPE));
+					assertTrue(elasticsearchSvc.performIndex(ElasticsearchSvcImpl.CODE_INDEX, codeableConceptId2, codeJson2Document, ElasticsearchSvcImpl.CODE_DOCUMENT_TYPE));
 				}
 
 				Calendar observationDate = new GregorianCalendar();
@@ -355,7 +371,7 @@ public class LastNElasticsearchSvcMultipleObservationsIT {
 				observationJson.setEffectiveDtm(effectiveDtm);
 
 				String observationDocument = ourMapperNonPrettyPrint.writeValueAsString(observationJson);
-				assertTrue(elasticsearchSvc.performIndex(OBSERVATION_INDEX, identifier, observationDocument, OBSERVATION_DOCUMENT_TYPE));
+				assertTrue(elasticsearchSvc.performIndex(ElasticsearchSvcImpl.OBSERVATION_INDEX, identifier, observationDocument, ElasticsearchSvcImpl.OBSERVATION_DOCUMENT_TYPE));
 
 				if (createdPatientObservationMap.containsKey(subject)) {
 					Map<String, List<Date>> observationCodeMap = createdPatientObservationMap.get(subject);
@@ -393,7 +409,8 @@ public class LastNElasticsearchSvcMultipleObservationsIT {
 	@Test
 	public void testLastNNoParamsQuery() {
 		SearchParameterMap searchParameterMap = new SearchParameterMap();
-		List<ObservationJson> observations = elasticsearchSvc.executeLastNWithAllFields(searchParameterMap, 1, 100);
+		searchParameterMap.setLastNMax(1);
+		List<ObservationJson> observations = elasticsearchSvc.executeLastNWithAllFields(searchParameterMap, myFhirContext);
 
 		assertEquals(2, observations.size());
 

hapi-fhir-jpaserver-base/src/test/java/ca/uhn/fhir/jpa/search/lastn/LastNElasticsearchSvcSingleObservationIT.java

@@ -1,5 +1,6 @@
 package ca.uhn.fhir.jpa.search.lastn;
 
+import ca.uhn.fhir.context.FhirContext;
 import ca.uhn.fhir.jpa.search.lastn.config.TestElasticsearchConfig;
 import ca.uhn.fhir.jpa.search.lastn.json.CodeJson;
 import ca.uhn.fhir.jpa.search.lastn.json.ObservationJson;
@@ -67,12 +68,14 @@ public class LastNElasticsearchSvcSingleObservationIT {
 	final String CODEFIRSTCODINGSYSTEM = "http://mycodes.org/fhir/observation-code";
 	final String CODEFIRSTCODINGCODE = "test-code";
 	final String CODEFIRSTCODINGDISPLAY = "test-code display";
-	final String CODESECONDCODINGSYSTEM = "http://myalternatecodes.org/fhir/observation-code";
+//	final String CODESECONDCODINGSYSTEM = "http://myalternatecodes.org/fhir/observation-code";
-	final String CODESECONDCODINGCODE = "test-alt-code";
+//	final String CODESECONDCODINGCODE = "test-alt-code";
-	final String CODESECONDCODINGDISPLAY = "test-alt-code display";
+//	final String CODESECONDCODINGDISPLAY = "test-alt-code display";
-	final String CODETHIRDCODINGSYSTEM = "http://mysecondaltcodes.org/fhir/observation-code";
+//	final String CODETHIRDCODINGSYSTEM = "http://mysecondaltcodes.org/fhir/observation-code";
-	final String CODETHIRDCODINGCODE = "test-second-alt-code";
+//	final String CODETHIRDCODINGCODE = "test-second-alt-code";
-	final String CODETHIRDCODINGDISPLAY = "test-second-alt-code display";
+//	final String CODETHIRDCODINGDISPLAY = "test-second-alt-code display";
+
+	final FhirContext myFhirContext = FhirContext.forR4();
 
 	@BeforeClass
 	public static void beforeClass() {
@@ -85,8 +88,8 @@ public class LastNElasticsearchSvcSingleObservationIT {
 
 	@After
 	public void after() throws IOException {
-		elasticsearchSvc.deleteAllDocuments(IndexConstants.OBSERVATION_INDEX);
+		elasticsearchSvc.deleteAllDocuments(ElasticsearchSvcImpl.OBSERVATION_INDEX);
-		elasticsearchSvc.deleteAllDocuments(IndexConstants.CODE_INDEX);
+		elasticsearchSvc.deleteAllDocuments(ElasticsearchSvcImpl.CODE_INDEX);
 	}
 
 	@Test
@@ -102,14 +105,16 @@ public class LastNElasticsearchSvcSingleObservationIT {
 		TokenParam codeParam = new TokenParam(CODEFIRSTCODINGSYSTEM, CODEFIRSTCODINGCODE);
 		searchParameterMap.add(Observation.SP_CODE, new TokenAndListParam().addAnd(new TokenOrListParam().addOr(codeParam)));
 
+		searchParameterMap.setLastNMax(3);
+
 		// execute Observation ID search
-		List<String> observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap, 3, 100);
+		List<String> observationIdsOnly = elasticsearchSvc.executeLastN(searchParameterMap, myFhirContext, 100);
 
 		assertEquals(1, observationIdsOnly.size());
 		assertEquals(RESOURCEPID, observationIdsOnly.get(0));
 
 		// execute Observation search for all search fields
-		List<ObservationJson> observations = elasticsearchSvc.executeLastNWithAllFields(searchParameterMap, 3, 100);
+		List<ObservationJson> observations = elasticsearchSvc.executeLastNWithAllFields(searchParameterMap, myFhirContext);
 
 		validateFullObservationSearch(observations);
 	}
@@ -243,7 +248,7 @@ public class LastNElasticsearchSvcSingleObservationIT {
 		assertEquals(String.valueOf(CodeSystemHash.hashCodeSystem(CODEFIRSTCODINGSYSTEM, CODEFIRSTCODINGCODE)), code_coding_code_system_hash);
 
 		// Retrieve all Observation codes
-		List<CodeJson> codes = elasticsearchSvc.queryAllIndexedObservationCodes(1000);
+		List<CodeJson> codes = elasticsearchSvc.queryAllIndexedObservationCodes();
 		assertEquals(1, codes.size());
 		CodeJson persistedObservationCode = codes.get(0);
 
@@ -331,11 +336,11 @@ public class LastNElasticsearchSvcSingleObservationIT {
 		indexedObservation.setCode(codeableConceptField);
 
 		String observationDocument = ourMapperNonPrettyPrint.writeValueAsString(indexedObservation);
-		assertTrue(elasticsearchSvc.performIndex(IndexConstants.OBSERVATION_INDEX, RESOURCEPID, observationDocument, IndexConstants.OBSERVATION_DOCUMENT_TYPE));
+		assertTrue(elasticsearchSvc.performIndex(ElasticsearchSvcImpl.OBSERVATION_INDEX, RESOURCEPID, observationDocument, ElasticsearchSvcImpl.OBSERVATION_DOCUMENT_TYPE));
 
 		CodeJson observationCode = new CodeJson(codeableConceptField, OBSERVATIONSINGLECODEID);
 		String codeDocument = ourMapperNonPrettyPrint.writeValueAsString(observationCode);
-		assertTrue(elasticsearchSvc.performIndex(IndexConstants.CODE_INDEX, OBSERVATIONSINGLECODEID, codeDocument, IndexConstants.CODE_DOCUMENT_TYPE));
+		assertTrue(elasticsearchSvc.performIndex(ElasticsearchSvcImpl.CODE_INDEX, OBSERVATIONSINGLECODEID, codeDocument, ElasticsearchSvcImpl.CODE_DOCUMENT_TYPE));
 
 		try {
 			Thread.sleep(1000L);

hapi-fhir-jpaserver-searchparam/src/main/java/ca/uhn/fhir/jpa/searchparam/util/LastNParameterHelper.java

@@ -35,4 +35,66 @@ public class LastNParameterHelper {
 			throw new InvalidRequestException("$lastn operation is not implemented for FHIR Version " + theContext.getVersion().getVersion().getFhirVersionString());
 		}
 	}
+
+	public static String getSubjectParamName(FhirContext theContext) {
+		if (theContext.getVersion().getVersion() == FhirVersionEnum.R5) {
+			return org.hl7.fhir.r5.model.Observation.SP_SUBJECT;
+		} else if (theContext.getVersion().getVersion() == FhirVersionEnum.R4) {
+			return org.hl7.fhir.r4.model.Observation.SP_SUBJECT;
+		} else if (theContext.getVersion().getVersion() == FhirVersionEnum.DSTU3) {
+			return org.hl7.fhir.dstu3.model.Observation.SP_SUBJECT;
+		} else {
+			throw new InvalidRequestException("$lastn operation is not implemented for FHIR Version " + theContext.getVersion().getVersion().getFhirVersionString());
+		}
+	}
+
+	public static String getPatientParamName(FhirContext theContext) {
+		if (theContext.getVersion().getVersion() == FhirVersionEnum.R5) {
+			return org.hl7.fhir.r5.model.Observation.SP_PATIENT;
+		} else if (theContext.getVersion().getVersion() == FhirVersionEnum.R4) {
+			return org.hl7.fhir.r4.model.Observation.SP_PATIENT;
+		} else if (theContext.getVersion().getVersion() == FhirVersionEnum.DSTU3) {
+			return org.hl7.fhir.dstu3.model.Observation.SP_PATIENT;
+		} else {
+			throw new InvalidRequestException("$lastn operation is not implemented for FHIR Version " + theContext.getVersion().getVersion().getFhirVersionString());
+		}
+	}
+
+	public static String getEffectiveParamName(FhirContext theContext) {
+		if (theContext.getVersion().getVersion() == FhirVersionEnum.R5) {
+			return org.hl7.fhir.r5.model.Observation.SP_DATE;
+		} else if (theContext.getVersion().getVersion() == FhirVersionEnum.R4) {
+			return org.hl7.fhir.r4.model.Observation.SP_DATE;
+		} else if (theContext.getVersion().getVersion() == FhirVersionEnum.DSTU3) {
+			return org.hl7.fhir.dstu3.model.Observation.SP_DATE;
+		} else {
+			throw new InvalidRequestException("$lastn operation is not implemented for FHIR Version " + theContext.getVersion().getVersion().getFhirVersionString());
+		}
+	}
+
+	public static String getCategoryParamName(FhirContext theContext) {
+		if (theContext.getVersion().getVersion() == FhirVersionEnum.R5) {
+			return org.hl7.fhir.r5.model.Observation.SP_CATEGORY;
+		} else if (theContext.getVersion().getVersion() == FhirVersionEnum.R4) {
+			return org.hl7.fhir.r4.model.Observation.SP_CATEGORY;
+		} else if (theContext.getVersion().getVersion() == FhirVersionEnum.DSTU3) {
+			return org.hl7.fhir.dstu3.model.Observation.SP_CATEGORY;
+		} else {
+			throw new InvalidRequestException("$lastn operation is not implemented for FHIR Version " + theContext.getVersion().getVersion().getFhirVersionString());
+		}
+	}
+
+	public static String getCodeParamName(FhirContext theContext) {
+		if (theContext.getVersion().getVersion() == FhirVersionEnum.R5) {
+			return org.hl7.fhir.r5.model.Observation.SP_CODE;
+		} else if (theContext.getVersion().getVersion() == FhirVersionEnum.R4) {
+			return org.hl7.fhir.r4.model.Observation.SP_CODE;
+		} else if (theContext.getVersion().getVersion() == FhirVersionEnum.DSTU3) {
+			return org.hl7.fhir.dstu3.model.Observation.SP_CODE;
+		} else {
+			throw new InvalidRequestException("$lastn operation is not implemented for FHIR Version " + theContext.getVersion().getVersion().getFhirVersionString());
+		}
+	}
+
+
 }