fix: foreign key constraint ambiguity in generated delegate prisma schema (#1060)

Author: ymc9

packages/schema/src/plugins/prisma/schema-generator.ts

@@ -456,6 +456,11 @@ export class PrismaSchemaGenerator {
                             new PrismaFieldAttribute('@relation', [
                                 new PrismaAttributeArg('fields', args),
                                 new PrismaAttributeArg('references', args),
+                                // generate a `map` argument for foreign key constraint disambiguation
+                                new PrismaAttributeArg(
+                                    'map',
+                                    new PrismaAttributeArgValue('String', `${relationField.name}_fk`)
+                                ),
                             ])
                         );
                     } else {

tests/integration/tests/enhancements/with-delegate/regressions.test.ts

@@ -0,0 +1,53 @@
+import { loadSchema } from '@zenstackhq/testtools';
+
+describe('Regression tests', () => {
+    it('FK Constraint Ambiguity', async () => {
+        const schema = `
+        model User {
+          id String @id @default(cuid())
+          name String
+        
+          userRankings UserRanking[]
+          userFavorites UserFavorite[]
+        }
+        
+        model Entity {
+          id String @id @default(cuid())
+          name String
+          type String
+          userRankings UserRanking[]
+          userFavorites UserFavorite[]
+        
+          @@delegate(type)
+        }
+        
+        model Person extends Entity {
+        }
+        
+        model Studio extends Entity {
+        }
+        
+        
+        model UserRanking {
+          id String @id @default(cuid())
+          rank Int
+        
+          entityId String
+          entity Entity @relation(fields: [entityId], references: [id], onUpdate: NoAction)
+          userId String
+          user User @relation(fields: [userId], references: [id], onDelete: Cascade, onUpdate: NoAction)
+        }
+        
+        model UserFavorite {
+          id String @id @default(cuid())
+        
+          entityId String
+          entity Entity @relation(fields: [entityId], references: [id], onUpdate: NoAction)
+          userId String
+          user User @relation(fields: [userId], references: [id], onDelete: Cascade, onUpdate: NoAction)
+        } 
+        `;
+
+        await loadSchema(schema, { pushDb: false, provider: 'postgresql' });
+    });
+});