Add explicit primary key on models

Author: Jelle

wagtail_advanced_form_builder/models/email_form_field.py

@@ -7,6 +7,14 @@
 
 class EmailFormField(AbstractAdvancedFormField):
 
+    # Add explicit `id` primary key using Django's defaults for versions
+    # prior to 3.2 to avoid migrations when upgrading to that version.
+    id = models.AutoField(
+        primary_key=True,
+        auto_created=True,
+        serialize=False,
+        verbose_name='ID',
+    )
     page = ParentalKey(
         'wagtail_advanced_form_builder.EmailFormPage',
         on_delete=models.CASCADE,

wagtail_advanced_form_builder/models/form_field.py

@@ -7,6 +7,14 @@
 
 class FormField(AbstractAdvancedFormField):
 
+    # Add explicit `id` primary key using Django's defaults for versions
+    # prior to 3.2 to avoid migrations when upgrading to that version.
+    id = models.AutoField(
+        primary_key=True,
+        auto_created=True,
+        serialize=False,
+        verbose_name='ID',
+    )
     page = ParentalKey(
         'wagtail_advanced_form_builder.FormPage',
         on_delete=models.CASCADE,