user affiliation schema completed

backend/database/factories/UserAffiliationFactory.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace Database\Factories;
+
+use App\Models\Institution;
+use App\Models\Lists\UserPosition;
+use App\Models\User;
+use App\Models\UserAffiliation;
+use Illuminate\Database\Eloquent\Factories\Factory;
+
+/**
+ * @extends Factory<UserAffiliation>
+ */
+class UserAffiliationFactory extends Factory
+{
+    protected $model = UserAffiliation::class;
+
+    /**
+     * @return array<string, mixed>
+     */
+    public function definition(): array
+    {
+        return [
+            'institution_id' => Institution::factory(),
+            'user_id' => User::factory(),
+            'user_position_id' => UserPosition::factory(),
+            'start_year' => fake()->numberBetween(1980, (int) date('Y')),
+            'end_year' => null,
+            'legacy_user_id' => null,
+            'legacy_institution_id' => null,
+        ];
+    }
+}