fix: discard duplicated columns on update

src/query-builder/UpdateQueryBuilder.ts

@@ -394,7 +394,8 @@ export class UpdateQueryBuilder<Entity> extends QueryBuilder<Entity> implements
                 }
 
                 columns.forEach(column => {
-                    if (!column.isUpdate) { return; }
+                    if (!column.isUpdate || updatedColumns.includes(column)) { return; }
+
                     updatedColumns.push(column);
 
                     //

test/github-issues/8723/entity/Photo.ts

@@ -0,0 +1,21 @@
+import { 
+  Column, 
+  Entity,
+  OneToOne, 
+  JoinColumn, 
+  PrimaryColumn,
+} from "../../../../src";
+import { User } from "./User";
+
+@Entity()
+export class Photo {
+  @PrimaryColumn({ type: "int", nullable: false })
+  id: number;
+
+  @OneToOne(() => User, { nullable: true })
+  @JoinColumn({ name: "user_id" })
+  public user?: User;
+
+  @Column({ name: "user_id", nullable: true })
+  public userId?: number;
+}

test/github-issues/8723/entity/User.ts

@@ -0,0 +1,14 @@
+import { 
+  Column, 
+  Entity,
+  PrimaryColumn,
+} from "../../../../src";
+
+@Entity()
+export class User {
+  @PrimaryColumn({ type: "int", nullable: false })
+  id: number;
+
+  @Column()
+  name: string;
+}

test/github-issues/8723/issue-8723.ts

@@ -0,0 +1,28 @@
+import "reflect-metadata";
+import { createTestingConnections, closeTestingConnections, reloadTestingDatabases } from "../../utils/test-utils";
+import { Connection } from "../../../src/connection/Connection";
+import { User } from "./entity/User";
+import { Photo } from "./entity/Photo";
+
+describe("github issues > #8723 Fail on Update when reference exists together with FK: multiple assignments to same column ", () => {
+
+    let connections: Connection[];
+    before(async () => connections = await createTestingConnections({
+        entities: [__dirname + "/entity/*{.js,.ts}"],
+        schemaCreate: true,
+        dropSchema: true,
+    }));
+    beforeEach(() => reloadTestingDatabases(connections));
+    after(() => closeTestingConnections(connections));
+
+    it("should able to update when both reference and the id exist in the update object", () => Promise.all(connections.map(async connection => {
+        const photoRepository = connection.getRepository(Photo);
+        const userRepository = connection.getRepository(User);
+
+        const user = await userRepository.save({ id: 1, name: "Test" });
+        const photo = await photoRepository.save({ id: 1 });
+
+        await photoRepository.update({ id: photo.id }, { user, userId: user.id });
+    })));
+
+});