refactor: stop reading joinColumnName from relation field settings (#20304)

## Summary

`joinColumnName` on relation field settings is always derivable from the
field name (and the target object name for morph relations). This PR
stops reading it from settings anywhere in production code; the stored
value is no longer used.

The settings field is **not** removed from data yet — a follow-up can
drop it once we are confident nothing depends on the stored value.

## Helpers

The helpers are split by layer because frontend and backend hold morph
relations differently: the frontend has a base name plus a
`morphRelations[]` array, the backend has one row per target with the
name already morph-resolved.

| Helper | Layer | When to use |
|---|---|---|
| `computeRelationGqlFieldJoinColumnName` | Shared / frontend
(`gqlField`) | Non-morph relation on the frontend. |
| `computeMorphRelationGqlFieldName` | Shared / frontend (`gqlField`) |
Need the per-target morph gqlField name (e.g. `targetCompany`). |
| `computeMorphRelationGqlFieldJoinColumnName` | Shared / frontend
(`gqlField`) | Per-target morph join column on the frontend. Prefer over
the non-morph helper for any morph field — it forces the per-target
inputs. |
| `computeMorphOrRelationFieldJoinColumnName` | Backend
(`FlatFieldMetadata.name`) | Any backend read or write — the flat name
is already morph-resolved, so one helper covers both cases. |
| `computeMorphRelationFlatFieldName` | Backend
(`FlatFieldMetadata.name`) | **Mutation paths only** (create / update /
object rename). Reads consume the stored `field.name` and never call
this. |

## Test plan

- [x] Typecheck and lint (front, server, shared)
- [x] Existing unit tests pass
- [ ] CI green

packages/twenty-front/src/modules/object-metadata/utils/__tests__/shouldFieldBeQueried.test.ts

@@ -44,7 +44,7 @@ describe('shouldFieldBeQueried', () => {
       const res = shouldFieldBeQueried({
         gqlField: 'fieldNameId',
         fieldMetadata: {
-          name: 'fieldNameId',
+          name: 'fieldName',
           type: FieldMetadataType.RELATION,
           settings: {
             relationType: RelationType.MANY_TO_ONE,

packages/twenty-front/src/modules/object-metadata/utils/mapFieldMetadataToGraphQLQuery.ts

@@ -10,7 +10,11 @@ import {
   type ObjectPermissions,
   RelationType,
 } from 'twenty-shared/types';
-import { computeMorphRelationFieldName, isDefined } from 'twenty-shared/utils';
+import {
+  computeMorphRelationGqlFieldName,
+  computeRelationGqlFieldJoinColumnName,
+  isDefined,
+} from 'twenty-shared/utils';
 
 type MapFieldMetadataToGraphQLQueryArgs = {
   objectMetadataItems: EnrichedObjectMetadataItem[];
@@ -52,7 +56,7 @@ export const mapFieldMetadataToGraphQLQuery = ({
   ) {
     let gqlMorphField = '';
     for (const morphRelation of fieldMetadata.morphRelations ?? []) {
-      const relationFieldName = computeMorphRelationFieldName({
+      const relationFieldName = computeMorphRelationGqlFieldName({
         fieldName: fieldMetadata.name,
         relationType: fieldMetadata.settings?.relationType,
         targetObjectMetadataNameSingular:
@@ -168,7 +172,10 @@ ${mapObjectMetadataToGraphQLQuery({
       }
     }
 
-    if (gqlField === fieldMetadata.settings?.joinColumnName) {
+    if (
+      gqlField ===
+      computeRelationGqlFieldJoinColumnName({ name: fieldMetadata.name })
+    ) {
       return `${gqlField}`;
     }
 

packages/twenty-front/src/modules/object-metadata/utils/mapObjectMetadataToGraphQLQuery.ts

@@ -4,8 +4,17 @@ import { mapFieldMetadataToGraphQLQuery } from '@/object-metadata/utils/mapField
 import { shouldFieldBeQueried } from '@/object-metadata/utils/shouldFieldBeQueried';
 import { type RecordGqlFields } from '@/object-record/graphql/record-gql-fields/types/RecordGqlFields';
 import { isRecordGqlFieldsNode } from '@/object-record/graphql/utils/isRecordGraphlFieldsNode';
-import { FieldMetadataType, type ObjectPermissions } from 'twenty-shared/types';
-import { computeMorphRelationFieldName, isDefined } from 'twenty-shared/utils';
+import {
+  FieldMetadataType,
+  RelationType,
+  type ObjectPermissions,
+} from 'twenty-shared/types';
+import {
+  computeMorphRelationGqlFieldJoinColumnName,
+  computeMorphRelationGqlFieldName,
+  computeRelationGqlFieldJoinColumnName,
+  isDefined,
+} from 'twenty-shared/utils';
 
 type MapObjectMetadataToGraphQLQueryArgs = {
   objectMetadataItems: EnrichedObjectMetadataItem[];
@@ -46,12 +55,15 @@ export const mapObjectMetadataToGraphQLQuery = ({
 
   const manyToOneRelationFields = objectMetadataItem?.readableFields
     .filter((field) => field.isActive)
-    .filter(
-      (field) =>
-        field.type === FieldMetadataType.RELATION ||
-        field.type === FieldMetadataType.MORPH_RELATION,
-    )
-    .filter((field) => isDefined(field.settings?.joinColumnName));
+    .filter((field) => {
+      if (field.type === FieldMetadataType.RELATION) {
+        return field.relation?.type === RelationType.MANY_TO_ONE;
+      }
+      if (field.type === FieldMetadataType.MORPH_RELATION) {
+        return field.settings?.relationType === RelationType.MANY_TO_ONE;
+      }
+      return false;
+    });
 
   const manyToOneRelationGqlFieldWithFieldMetadata =
     manyToOneRelationFields.flatMap((fieldMetadata) => {
@@ -59,7 +71,9 @@ export const mapObjectMetadataToGraphQLQuery = ({
         fieldMetadata.type === FieldMetadataType.MORPH_RELATION;
       if (!isMorphRelation) {
         return {
-          gqlField: fieldMetadata.settings?.joinColumnName,
+          gqlField: computeRelationGqlFieldJoinColumnName({
+            name: fieldMetadata.name,
+          }),
           fieldMetadata: fieldMetadata,
         };
       }
@@ -69,14 +83,14 @@ export const mapObjectMetadataToGraphQLQuery = ({
       }
 
       return fieldMetadata.morphRelations.map((morphRelation) => ({
-        gqlField: `${computeMorphRelationFieldName({
+        gqlField: computeMorphRelationGqlFieldJoinColumnName({
           fieldName: fieldMetadata.name,
           relationType: morphRelation.type,
           targetObjectMetadataNameSingular:
             morphRelation.targetObjectMetadata.nameSingular,
           targetObjectMetadataNamePlural:
             morphRelation.targetObjectMetadata.namePlural,
-        })}Id`,
+        }),
         fieldMetadata: fieldMetadata,
       }));
     });
@@ -102,7 +116,7 @@ export const mapObjectMetadataToGraphQLQuery = ({
     }
 
     return fieldMetadata.morphRelations.map((morphRelation) => ({
-      gqlField: computeMorphRelationFieldName({
+      gqlField: computeMorphRelationGqlFieldName({
         fieldName: fieldMetadata.name,
         relationType: morphRelation.type,
         targetObjectMetadataNameSingular:

packages/twenty-front/src/modules/object-metadata/utils/shouldFieldBeQueried.ts

@@ -4,7 +4,11 @@ import { isUndefinedOrNull } from '~/utils/isUndefinedOrNull';
 
 import { isFieldMorphRelation } from '@/object-record/record-field/ui/types/guards/isFieldMorphRelation';
 import { isFieldRelation } from '@/object-record/record-field/ui/types/guards/isFieldRelation';
-import { isDefined } from 'twenty-shared/utils';
+import {
+  computeMorphRelationGqlFieldJoinColumnName,
+  computeRelationGqlFieldJoinColumnName,
+  isDefined,
+} from 'twenty-shared/utils';
 import { type FieldMetadataItem } from '@/object-metadata/types/FieldMetadataItem';
 
 export const shouldFieldBeQueried = ({
@@ -13,13 +17,35 @@ export const shouldFieldBeQueried = ({
   recordGqlFields,
 }: {
   gqlField: string;
-  fieldMetadata: Pick<FieldMetadataItem, 'name' | 'type' | 'settings'>;
+  fieldMetadata: Pick<
+    FieldMetadataItem,
+    'name' | 'type' | 'settings' | 'morphRelations'
+  >;
   objectRecord?: ObjectRecord;
   recordGqlFields?: RecordGqlOperationGqlRecordFields;
 }): any => {
+  const isRelationJoinColumn =
+    isFieldRelation(fieldMetadata) &&
+    computeRelationGqlFieldJoinColumnName({ name: fieldMetadata.name }) ===
+      gqlField;
+
+  const isMorphRelationJoinColumn =
+    isFieldMorphRelation(fieldMetadata) &&
+    isDefined(fieldMetadata.morphRelations) &&
+    fieldMetadata.morphRelations.some(
+      (morphRelation) =>
+        computeMorphRelationGqlFieldJoinColumnName({
+          fieldName: fieldMetadata.name,
+          relationType: morphRelation.type,
+          targetObjectMetadataNameSingular:
+            morphRelation.targetObjectMetadata.nameSingular,
+          targetObjectMetadataNamePlural:
+            morphRelation.targetObjectMetadata.namePlural,
+        }) === gqlField,
+    );
+
   const isJoinColumn: boolean =
-    (isFieldRelation(fieldMetadata) || isFieldMorphRelation(fieldMetadata)) &&
-    fieldMetadata.settings.joinColumnName === gqlField;
+    isRelationJoinColumn || isMorphRelationJoinColumn;
 
   if (
     isUndefinedOrNull(recordGqlFields) &&