diff --git a/src/logic/define/databaseAccessObjects/__snapshots__/defineDaoCodeFilesForDomainObjects.integration.test.ts.snap b/src/logic/define/databaseAccessObjects/__snapshots__/defineDaoCodeFilesForDomainObjects.integration.test.ts.snap
index 2958380..ef9d920 100644
--- a/src/logic/define/databaseAccessObjects/__snapshots__/defineDaoCodeFilesForDomainObjects.integration.test.ts.snap
+++ b/src/logic/define/databaseAccessObjects/__snapshots__/defineDaoCodeFilesForDomainObjects.integration.test.ts.snap
@@ -1849,13 +1849,14 @@ export const findById = async (
     "relpath": "trainStationDao/findById.ts",
   },
   GeneratedCodeFile {
-    "content": "import { HasId, HasMetadata } from 'type-fns';
+    "content": "import { HasMetadata } from 'type-fns';
 
 import { DatabaseConnection } from '$PATH_TO_DATABASE_CONNECTION';
 import { log } from '$PATH_TO_LOG_OBJECT';
 import { Geocode, TrainStation } from '$PATH_TO_DOMAIN_OBJECT';
 import { sqlQueryFindTrainStationByUnique } from '$PATH_TO_GENERATED_SQL_QUERY_FUNCTIONS';
 import { castFromDatabaseObject } from './castFromDatabaseObject';
+import { geocodeDao } from '../geocodeDao';
 
 export const sql = \`
   -- query_name = find_train_station_by_unique
@@ -1880,7 +1881,7 @@ export const findByUnique = async (
   {
     geocode,
   }: {
-    geocode: HasId<Geocode>;
+    geocode: Geocode;
   },
   context: { dbConnection: DatabaseConnection },
 ): Promise<HasMetadata<TrainStation> | null> => {
@@ -1888,7 +1889,7 @@ export const findByUnique = async (
     dbExecute: context.dbConnection.query,
     logDebug: log.debug,
     input: {
-      geocodeId: geocode.id,
+      geocodeId: geocode.id ? geocode.id : ((await geocodeDao.findByUnique(geocode, context))?.id ?? -1),
     },
   });
   const [dbObject, ...moreDbObjects] = results;
@@ -2227,13 +2228,14 @@ export const findById = async (
     "relpath": "invoiceLineItemDao/findById.ts",
   },
   GeneratedCodeFile {
-    "content": "import { HasId, HasMetadata } from 'type-fns';
+    "content": "import { HasMetadata } from 'type-fns';
 
 import { DatabaseConnection } from '$PATH_TO_DATABASE_CONNECTION';
 import { log } from '$PATH_TO_LOG_OBJECT';
 import { InvoiceLineItem, Price } from '$PATH_TO_DOMAIN_OBJECT';
 import { sqlQueryFindInvoiceLineItemByUnique } from '$PATH_TO_GENERATED_SQL_QUERY_FUNCTIONS';
 import { castFromDatabaseObject } from './castFromDatabaseObject';
+import { priceDao } from '../priceDao';
 
 export const sql = \`
   -- query_name = find_invoice_line_item_by_unique
@@ -2262,7 +2264,7 @@ export const findByUnique = async (
     title,
     explanation,
   }: {
-    price: HasId<Price>;
+    price: Price;
     title: string;
     explanation: string;
   },
@@ -2272,7 +2274,7 @@ export const findByUnique = async (
     dbExecute: context.dbConnection.query,
     logDebug: log.debug,
     input: {
-      priceId: price.id,
+      priceId: price.id ? price.id : ((await priceDao.findByUnique(price, context))?.id ?? -1),
       title,
       explanation,
     },
diff --git a/src/logic/define/databaseAccessObjects/__snapshots__/defineDaoFindByMethodCodeForDomainObject.test.ts.snap b/src/logic/define/databaseAccessObjects/__snapshots__/defineDaoFindByMethodCodeForDomainObject.test.ts.snap
index c623406..a4841dc 100644
--- a/src/logic/define/databaseAccessObjects/__snapshots__/defineDaoFindByMethodCodeForDomainObject.test.ts.snap
+++ b/src/logic/define/databaseAccessObjects/__snapshots__/defineDaoFindByMethodCodeForDomainObject.test.ts.snap
@@ -284,13 +284,15 @@ export const findByUnique = async (
 `;
 
 exports[`defineDaoFindByMethodCodeForDomainObject findByUnique should look correct for domain entity that is unique on references, solo and array, implicit and nested 1`] = `
-"import { HasId, HasMetadata } from 'type-fns';
+"import { HasMetadata } from 'type-fns';
 
 import { DatabaseConnection } from '$PATH_TO_DATABASE_CONNECTION';
 import { log } from '$PATH_TO_LOG_OBJECT';
 import { Geocode, Train, TrainBadge } from '$PATH_TO_DOMAIN_OBJECT';
 import { sqlQueryFindTrainByUnique } from '$PATH_TO_GENERATED_SQL_QUERY_FUNCTIONS';
 import { castFromDatabaseObject } from './castFromDatabaseObject';
+import { geocodeDao } from '../geocodeDao';
+import { trainBadgeDao } from '../trainBadgeDao';
 
 export const sql = \`
   -- query_name = find_train_by_unique
@@ -357,8 +359,8 @@ export const findByUnique = async (
     locomotiveUuids,
     leadEngineerUuid,
   }: {
-    homeStationGeocode: HasId<Geocode>;
-    badges: HasId<TrainBadge>[];
+    homeStationGeocode: Geocode;
+    badges: TrainBadge[];
     locomotiveUuids: string[];
     leadEngineerUuid: string;
   },
@@ -368,8 +370,8 @@ export const findByUnique = async (
     dbExecute: context.dbConnection.query,
     logDebug: log.debug,
     input: {
-      homeStationGeocodeId: homeStationGeocode.id,
-      badgeIds: badges.map((trainBadge) => trainBadge.id),
+      homeStationGeocodeId: homeStationGeocode.id ? homeStationGeocode.id : ((await geocodeDao.findByUnique(homeStationGeocode, context))?.id ?? -1),
+      badgeIds: await Promise.all(badges.map(async (trainBadge) => trainBadge.id ? trainBadge.id : ((await trainBadgeDao.findByUnique(trainBadge, context))?.id ?? -1) )),
       locomotiveUuids,
       leadEngineerUuid,
     },
@@ -592,13 +594,14 @@ export const findByUnique = async (
 `;
 
 exports[`defineDaoFindByMethodCodeForDomainObject findByUnique should look correct for simple literal that references another literal 1`] = `
-"import { HasId, HasMetadata } from 'type-fns';
+"import { HasMetadata } from 'type-fns';
 
 import { DatabaseConnection } from '$PATH_TO_DATABASE_CONNECTION';
 import { log } from '$PATH_TO_LOG_OBJECT';
 import { InvoiceLineItem, Price } from '$PATH_TO_DOMAIN_OBJECT';
 import { sqlQueryFindInvoiceLineItemByUnique } from '$PATH_TO_GENERATED_SQL_QUERY_FUNCTIONS';
 import { castFromDatabaseObject } from './castFromDatabaseObject';
+import { priceDao } from '../priceDao';
 
 export const sql = \`
   -- query_name = find_invoice_line_item_by_unique
@@ -622,7 +625,7 @@ export const findByUnique = async (
   {
     price,
   }: {
-    price: HasId<Price>;
+    price: Price;
   },
   context: { dbConnection: DatabaseConnection },
 ): Promise<HasMetadata<InvoiceLineItem> | null> => {
@@ -630,7 +633,7 @@ export const findByUnique = async (
     dbExecute: context.dbConnection.query,
     logDebug: log.debug,
     input: {
-      priceId: price.id,
+      priceId: price.id ? price.id : ((await priceDao.findByUnique(price, context))?.id ?? -1),
     },
   });
   const [dbObject, ...moreDbObjects] = results;
@@ -641,13 +644,14 @@ export const findByUnique = async (
 `;
 
 exports[`defineDaoFindByMethodCodeForDomainObject findByUnique should look for a domain entity unique on a nested domain object 1`] = `
-"import { HasId, HasMetadata } from 'type-fns';
+"import { HasMetadata } from 'type-fns';
 
 import { DatabaseConnection } from '$PATH_TO_DATABASE_CONNECTION';
 import { log } from '$PATH_TO_LOG_OBJECT';
 import { Geocode, Station } from '$PATH_TO_DOMAIN_OBJECT';
 import { sqlQueryFindStationByUnique } from '$PATH_TO_GENERATED_SQL_QUERY_FUNCTIONS';
 import { castFromDatabaseObject } from './castFromDatabaseObject';
+import { geocodeDao } from '../geocodeDao';
 
 export const sql = \`
   -- query_name = find_station_by_unique
@@ -671,7 +675,7 @@ export const findByUnique = async (
   {
     geocode,
   }: {
-    geocode: HasId<Geocode>;
+    geocode: Geocode;
   },
   context: { dbConnection: DatabaseConnection },
 ): Promise<HasMetadata<Station> | null> => {
@@ -679,7 +683,7 @@ export const findByUnique = async (
     dbExecute: context.dbConnection.query,
     logDebug: log.debug,
     input: {
-      geocodeId: geocode.id,
+      geocodeId: geocode.id ? geocode.id : ((await geocodeDao.findByUnique(geocode, context))?.id ?? -1),
     },
   });
   const [dbObject, ...moreDbObjects] = results;
diff --git a/src/logic/define/databaseAccessObjects/defineDaoFindByMethodCodeForDomainObject.test.ts b/src/logic/define/databaseAccessObjects/defineDaoFindByMethodCodeForDomainObject.test.ts
index fec3f72..a9914c7 100644
--- a/src/logic/define/databaseAccessObjects/defineDaoFindByMethodCodeForDomainObject.test.ts
+++ b/src/logic/define/databaseAccessObjects/defineDaoFindByMethodCodeForDomainObject.test.ts
@@ -1190,7 +1190,7 @@ async (
   {
     geocode,
   }: {
-    geocode: HasId<Geocode>;
+    geocode: Geocode;
   },
   context
       `.trim(),
@@ -1721,8 +1721,8 @@ async (
     locomotiveUuids,
     leadEngineerUuid,
   }: {
-    homeStationGeocode: HasId<Geocode>;
-    badges: HasId<TrainBadge>[];
+    homeStationGeocode: Geocode;
+    badges: TrainBadge[];
     locomotiveUuids: string[];
     leadEngineerUuid: string;
   },
diff --git a/src/logic/define/databaseAccessObjects/defineDaoFindByMethodCodeForDomainObject.ts b/src/logic/define/databaseAccessObjects/defineDaoFindByMethodCodeForDomainObject.ts
index e239fd1..8f3d7d3 100644
--- a/src/logic/define/databaseAccessObjects/defineDaoFindByMethodCodeForDomainObject.ts
+++ b/src/logic/define/databaseAccessObjects/defineDaoFindByMethodCodeForDomainObject.ts
@@ -13,6 +13,7 @@ import { SqlSchemaPropertyMetadata } from '../../../domain/objects/SqlSchemaProp
 import { SqlSchemaReferenceMethod } from '../../../domain/objects/SqlSchemaReferenceMetadata';
 import { SqlSchemaToDomainObjectRelationship } from '../../../domain/objects/SqlSchemaToDomainObjectRelationship';
 import { UnexpectedCodePathDetectedError } from '../../UnexpectedCodePathDetectedError';
+import { castDomainObjectNameToDaoName } from './castDomainObjectNameToDaoName';
 import { defineOutputTypeOfFoundDomainObject } from './defineOutputTypeOfFoundDomainObject';
 import {
   defineQueryFunctionInputExpressionForDomainObjectProperty,
@@ -48,7 +49,7 @@ const getTypescriptTypeForDomainObjectProperty = ({
     return `${domainObjectName}['${domainObjectProperty.name}']`;
   if (domainObjectProperty.type === DomainObjectPropertyType.REFERENCE) {
     const referencedDomainObjectName = sqlSchemaProperty.reference!.of.name;
-    return `HasId<${referencedDomainObjectName}>`;
+    return referencedDomainObjectName;
   }
   if (domainObjectProperty.type === DomainObjectPropertyType.ARRAY) {
     if (
@@ -57,7 +58,7 @@ const getTypescriptTypeForDomainObjectProperty = ({
     )
       return 'string[]';
     const referencedDomainObjectName = sqlSchemaProperty.reference!.of.name;
-    return `HasId<${referencedDomainObjectName}>[]`;
+    return `${referencedDomainObjectName}[]`;
   }
   throw new UnexpectedCodePathDetectedError({
     reason:
@@ -141,9 +142,7 @@ export const defineDaoFindByMethodCodeForDomainObject = ({
   const imports = [
     ...new Set([
       // always present imports
-      `import { ${
-        referencedDomainObjectNames.length > 1 ? 'HasId, ' : ''
-      }HasMetadata } from 'type-fns';`,
+      `import { HasMetadata } from 'type-fns';`,
       '', // split module from relative imports
       "import { DatabaseConnection } from '$PATH_TO_DATABASE_CONNECTION';",
       "import { log } from '$PATH_TO_LOG_OBJECT';",
@@ -152,6 +151,24 @@ export const defineDaoFindByMethodCodeForDomainObject = ({
         .join(', ')} } from '$PATH_TO_DOMAIN_OBJECT';`,
       `import { sqlQueryFind${domainObject.name}By${findByQueryType} } from '$PATH_TO_GENERATED_SQL_QUERY_FUNCTIONS';`,
       "import { castFromDatabaseObject } from './castFromDatabaseObject';",
+      ...sqlSchemaRelationship.properties
+        .map((property) =>
+          property.sqlSchema.reference?.method ===
+          SqlSchemaReferenceMethod.DIRECT_BY_NESTING
+            ? property.sqlSchema.reference.of.name
+            : null,
+        )
+        .filter(isPresent)
+        .filter((nestedDomainObjectName) =>
+          referencedDomainObjectNames.includes(nestedDomainObjectName),
+        )
+        .map((referencedDomainObjectName) => {
+          const nameOfDaoToImport = castDomainObjectNameToDaoName(
+            referencedDomainObjectName,
+          );
+          return `import { ${nameOfDaoToImport} } from '../${nameOfDaoToImport}';`;
+        })
+        .sort(),
     ]),
   ];
 
diff --git a/src/logic/define/databaseAccessObjects/defineQueryFunctionInputExpressionForDomainObjectProperty.test.ts b/src/logic/define/databaseAccessObjects/defineQueryFunctionInputExpressionForDomainObjectProperty.test.ts
index 099034a..8ee27b4 100644
--- a/src/logic/define/databaseAccessObjects/defineQueryFunctionInputExpressionForDomainObjectProperty.test.ts
+++ b/src/logic/define/databaseAccessObjects/defineQueryFunctionInputExpressionForDomainObjectProperty.test.ts
@@ -449,7 +449,9 @@ describe('defineQueryFunctionInputExpressionForDomainObjectProperty', () => {
           ],
           context: GetTypescriptCodeForPropertyContext.FOR_FIND_BY_QUERY,
         });
-      expect(expression).toEqual('geocodeId: geocode.id');
+      expect(expression).toEqual(
+        'geocodeId: geocode.id ? geocode.id : ((await geocodeDao.findByUnique(geocode, context))?.id ?? -1)',
+      );
     });
     it('should define the input expression correctly for a solo, nullable, DIRECT_BY_NESTING reference', () => {
       const expression =
@@ -517,7 +519,7 @@ describe('defineQueryFunctionInputExpressionForDomainObjectProperty', () => {
           context: GetTypescriptCodeForPropertyContext.FOR_FIND_BY_QUERY,
         });
       expect(expression).toEqual(
-        'geocodeId: geocode === null ? null : geocode.id',
+        'geocodeId: geocode === null ? null : geocode.id ? geocode.id : ((await geocodeDao.findByUnique(geocode, context))?.id ?? -1)',
       );
     });
     it('should define the input expression correctly for an array of IMPLICIT_BY_UUID references', () => {
@@ -629,7 +631,7 @@ describe('defineQueryFunctionInputExpressionForDomainObjectProperty', () => {
           context: GetTypescriptCodeForPropertyContext.FOR_FIND_BY_QUERY,
         });
       expect(expression).toEqual(
-        'geocodeIds: geocodes.map((geocode) => geocode.id)',
+        'geocodeIds: await Promise.all(geocodes.map(async (geocode) => geocode.id ? geocode.id : ((await geocodeDao.findByUnique(geocode, context))?.id ?? -1) ))',
       );
     });
   });
diff --git a/src/logic/define/databaseAccessObjects/defineQueryFunctionInputExpressionForDomainObjectProperty.ts b/src/logic/define/databaseAccessObjects/defineQueryFunctionInputExpressionForDomainObjectProperty.ts
index 5658b37..f52b955 100644
--- a/src/logic/define/databaseAccessObjects/defineQueryFunctionInputExpressionForDomainObjectProperty.ts
+++ b/src/logic/define/databaseAccessObjects/defineQueryFunctionInputExpressionForDomainObjectProperty.ts
@@ -89,7 +89,9 @@ export const defineQueryFunctionInputExpressionForDomainObjectProperty = ({
       // e.g., `geocodeId: geocode.id`
       return `${camelCase(sqlSchemaProperty.name)}: ${nullabilityPrefix}${
         domainObjectProperty.name
-      }.id`;
+      }.id ? ${domainObjectPropertyVariableName}.id : ((await ${castDomainObjectNameToDaoName(
+        referencedDomainObjectName,
+      )}.findByUnique(${domainObjectPropertyVariableName}, context))?.id ?? -1)`;
     }
 
     // handle array of references
@@ -109,11 +111,17 @@ export const defineQueryFunctionInputExpressionForDomainObjectProperty = ({
         )}.upsert({ ${camelCase(referencedSqlSchemaName)} }, context)).id))`;
 
       // e.g., `geocodeIds: geocodes.map(geocode => geocode.id)`
-      return `${camelCase(sqlSchemaProperty.name)}: ${
+      return `${camelCase(sqlSchemaProperty.name)}: await Promise.all(${
         domainObjectProperty.name
-      }.map((${camelCase(referencedSqlSchemaName)}) => ${camelCase(
+      }.map(async (${camelCase(referencedSqlSchemaName)}) => ${camelCase(
         referencedSqlSchemaName,
-      )}.id)`;
+      )}.id ? ${camelCase(
+        referencedSqlSchemaName,
+      )}.id : ((await ${castDomainObjectNameToDaoName(
+        referencedDomainObjectName,
+      )}.findByUnique(${camelCase(
+        referencedSqlSchemaName,
+      )}, context))?.id ?? -1) ))`;
     }
   }