diff --git a/package-lock.json b/package-lock.json
index 6884301..dd9930e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
 	"name": "@comake/skl-js-engine",
-	"version": "0.19.0",
+	"version": "0.20.0",
 	"lockfileVersion": 2,
 	"requires": true,
 	"packages": {
 		"": {
 			"name": "@comake/skl-js-engine",
-			"version": "0.19.0",
+			"version": "0.20.0",
 			"license": "BSD-4-Clause",
 			"dependencies": {
 				"@comake/openapi-operation-executor": "^0.11.1",
diff --git a/package.json b/package.json
index de26a05..1a1fb96 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "@comake/skl-js-engine",
-	"version": "0.19.0",
+	"version": "0.20.0",
 	"description": "Standard Knowledge Language Javascript Engine",
 	"keywords": [
 		"skl",
diff --git a/src/storage/FindOptionsTypes.ts b/src/storage/FindOptionsTypes.ts
index c99fc07..43ac687 100644
--- a/src/storage/FindOptionsTypes.ts
+++ b/src/storage/FindOptionsTypes.ts
@@ -1,4 +1,5 @@
 /* eslint-disable @typescript-eslint/naming-convention */
+import type { Variable } from 'sparqljs';
 import type { OrArray, JSONArray, JSONObject } from '../util/Types';
 import type { FindOperator } from './FindOperator';
 import type { InverseRelationOperatorValue } from './operator/InverseRelation';
@@ -12,6 +13,8 @@ export interface FindOneOptions {
   relations?: FindOptionsRelations;
   order?: FindOptionsOrder;
   skipFraming?: boolean;
+  group?: Variable;
+  entitySelectVariable?: Variable;
 }
 
 export type FindOptionsRelationsValue = |
diff --git a/src/storage/query-adapter/sparql/SparqlQueryAdapter.ts b/src/storage/query-adapter/sparql/SparqlQueryAdapter.ts
index 7d4a133..6d479b4 100644
--- a/src/storage/query-adapter/sparql/SparqlQueryAdapter.ts
+++ b/src/storage/query-adapter/sparql/SparqlQueryAdapter.ts
@@ -128,10 +128,11 @@ export class SparqlQueryAdapter implements QueryAdapter {
     const queryData = queryBuilder.buildEntitySelectPatternsFromOptions(entityVariable, options);
     const entitySelectQuery = queryData.where.length > 0
       ? createSparqlSelectQuery(
-        entityVariable,
+        options?.entitySelectVariable ?? entityVariable,
         queryData.where,
         queryData.orders,
-        queryData.group,
+        // FIXME: This will not work if queryData.group is defined, figure out what can make it defined.
+        queryData.group ?? options?.group,
         options?.limit,
         options?.offset,
       )
diff --git a/src/storage/query-adapter/sparql/SparqlQueryBuilder.ts b/src/storage/query-adapter/sparql/SparqlQueryBuilder.ts
index 38f8c76..d5a51aa 100644
--- a/src/storage/query-adapter/sparql/SparqlQueryBuilder.ts
+++ b/src/storage/query-adapter/sparql/SparqlQueryBuilder.ts
@@ -681,7 +681,7 @@ export class SparqlQueryBuilder {
     return createSparqlNotEqualOperation(leftSide, rightSide as Expression);
   }
 
-  private resolveValueToTerm(value: FieldPrimitiveValue | ValueWhereFieldObject): NamedNode | Literal {
+  private resolveValueToTerm(value: FieldPrimitiveValue | ValueWhereFieldObject): NamedNode | Literal | Variable {
     if (typeof value === 'object' && '@value' in value) {
       return valueToLiteral(
         (value as ValueWhereFieldObject)['@value'],
diff --git a/src/util/TripleUtil.ts b/src/util/TripleUtil.ts
index 09e7a7e..0cba7d3 100644
--- a/src/util/TripleUtil.ts
+++ b/src/util/TripleUtil.ts
@@ -1,6 +1,6 @@
 /* eslint-disable @typescript-eslint/naming-convention */
 import DataFactory from '@rdfjs/data-model';
-import type { Quad, Quad_Object, Quad_Subject, Literal } from '@rdfjs/types';
+import type { Quad, Quad_Object, Quad_Subject, Literal, Variable } from '@rdfjs/types';
 import * as jsonld from 'jsonld';
 import type { ContextDefinition, GraphObject, NodeObject, ValueObject } from 'jsonld';
 import type { Frame } from 'jsonld/jsonld-spec';
@@ -254,7 +254,7 @@ export async function triplesToJsonldWithFrame(
 export function valueToLiteral(
   value: string | boolean | number | Date | JSONObject | JSONArray,
   datatype?: string,
-): Literal {
+): Literal | Variable {
   if (datatype) {
     if (datatype === '@json' || datatype === RDF.JSON) {
       return DataFactory.literal(JSON.stringify(value), RDF.JSON);
@@ -270,6 +270,9 @@ export function valueToLiteral(
   if (typeof value === 'boolean') {
     return DataFactory.literal(value.toString(), XSD.boolean);
   }
+  if (typeof value === 'string' && value.startsWith('?') && value.length > 1) {
+    return DataFactory.variable(value.slice(1));
+  }
   if (value instanceof Date) {
     return DataFactory.literal(value.toISOString(), XSD.dateTime);
   }
diff --git a/test/unit/storage/query-adapter/sparql/SparqlQueryAdapter.test.ts b/test/unit/storage/query-adapter/sparql/SparqlQueryAdapter.test.ts
index ec062d1..6d5e549 100644
--- a/test/unit/storage/query-adapter/sparql/SparqlQueryAdapter.test.ts
+++ b/test/unit/storage/query-adapter/sparql/SparqlQueryAdapter.test.ts
@@ -701,6 +701,39 @@ describe('a SparqlQueryAdapter', (): void => {
           '}',
         ]);
       });
+
+    it('executes a group by query with custom entity select variable.', async(): Promise<void> => {
+      await adapter.findAll({
+        where: {
+          type: 'https://schema.org/Place',
+          'https://standardknowledge.com/ontologies/core/deduplicationGroup': '?deduplicationGroup'
+        },
+        group: DataFactory.variable('deduplicationGroup'),
+        entitySelectVariable: {
+          variable: DataFactory.variable('entity'),
+          expression: {
+            type: 'aggregate',
+            aggregation: 'MIN',
+            expression: DataFactory.variable('entity'),
+          },
+        },
+      });
+      expect(select).toHaveBeenCalledTimes(1);
+      expect(select.mock.calls[0][0].split('\n')).toEqual([
+        'CONSTRUCT { ?subject ?predicate ?object. }',
+        'WHERE {',
+        '  {',
+        '    SELECT DISTINCT (MIN(?entity) AS ?entity) WHERE {',
+        '      ?entity (<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>/(<http://www.w3.org/2000/01/rdf-schema#subClassOf>*)) <https://schema.org/Place>;',
+        '        <https://standardknowledge.com/ontologies/core/deduplicationGroup> ?deduplicationGroup.',
+        '      FILTER(EXISTS { GRAPH ?entity { ?entity ?c1 ?c2. } })',
+        '    }',
+        '    GROUP BY ?deduplicationGroup',
+        '  }',
+        '  GRAPH ?entity { ?subject ?predicate ?object. }',
+        '}',
+      ]);
+    });
   });
 
   describe('findAllBy', (): void => {