Fix db_column not being passed through on AutoFields (#168)

* Pass db_column through on tracked AutoFields

* Don't pass db_column through unless it is different

* Add tests for db_column

* Add missing migration for tests

* Add clarification for db_column

pghistory/core.py

@@ -237,10 +237,14 @@ def _generate_history_field(tracked_model, field):
     """
     field = tracked_model._meta.get_field(field)
 
+    # db_column is always a value even if the user didn't set it, so we
+    # need to double-check that it's different before we pass it through
+    db_column = field.db_column if field.db_column != field.name else None
+
     if isinstance(field, models.BigAutoField):
-        return models.BigIntegerField()
+        return models.BigIntegerField(db_column=db_column)
     elif isinstance(field, models.AutoField):
-        return models.IntegerField()
+        return models.IntegerField(db_column=db_column)
     elif not field.concrete:  # pragma: no cover
         # Django doesn't have any non-concrete fields that appear
         # in ._meta.fields, but packages like django-prices have

pghistory/tests/migrations/0014_customautofieldmodel_custombigautofieldmodel_and_more.py

@@ -0,0 +1,69 @@
+# Generated by Django 4.2.6 on 2024-09-24 17:46
+
+import pgtrigger.compiler
+import pgtrigger.migrations
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("tests", "0013_concreteparent_concretechild_concretechildevent_and_more"),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="CustomAutoFieldModel",
+            fields=[
+                (
+                    "id",
+                    models.AutoField(db_column="pk_id", primary_key=True, serialize=False),
+                ),
+            ],
+        ),
+        migrations.CreateModel(
+            name="CustomBigAutoFieldModel",
+            fields=[
+                (
+                    "id",
+                    models.BigAutoField(db_column="pk_id", primary_key=True, serialize=False),
+                ),
+            ],
+        ),
+        pgtrigger.migrations.RemoveTrigger(
+            model_name="ignoreautofieldssnapshotmodel",
+            name="update_update",
+        ),
+        pgtrigger.migrations.RemoveTrigger(
+            model_name="ignoreautofieldssnapshotmodel",
+            name="delete_delete",
+        ),
+        pgtrigger.migrations.AddTrigger(
+            model_name="ignoreautofieldssnapshotmodel",
+            trigger=pgtrigger.compiler.Trigger(
+                name="update_update",
+                sql=pgtrigger.compiler.UpsertTriggerSql(
+                    condition='WHEN (OLD."my_char_field" IS DISTINCT FROM (NEW."my_char_field") OR OLD."my_int_field" IS DISTINCT FROM (NEW."my_int_field"))',  # noqa: E501
+                    func='INSERT INTO "tests_ignoreautofieldssnapshotmodelcreatedatupdatedatmychardc6b" ("created_at", "my_char_field", "my_int_field", "pgh_context_id", "pgh_created_at", "pgh_label", "pgh_obj_id", "updated_at") VALUES (OLD."created_at", OLD."my_char_field", OLD."my_int_field", _pgh_attach_context(), NOW(), \'update\', OLD."id", OLD."updated_at"); RETURN NULL;',  # noqa: E501
+                    hash="e817c95f191e0d10b3e86643e2d8a050a864d45a",
+                    operation="UPDATE",
+                    pgid="pgtrigger_update_update_9dd1b",
+                    table="tests_ignoreautofieldssnapshotmodel",
+                    when="AFTER",
+                ),
+            ),
+        ),
+        pgtrigger.migrations.AddTrigger(
+            model_name="ignoreautofieldssnapshotmodel",
+            trigger=pgtrigger.compiler.Trigger(
+                name="delete_delete",
+                sql=pgtrigger.compiler.UpsertTriggerSql(
+                    func='INSERT INTO "tests_ignoreautofieldssnapshotmodelcreatedatupdatedatmychardc6b" ("created_at", "my_char_field", "my_int_field", "pgh_context_id", "pgh_created_at", "pgh_label", "pgh_obj_id", "updated_at") VALUES (OLD."created_at", OLD."my_char_field", OLD."my_int_field", _pgh_attach_context(), NOW(), \'delete\', OLD."id", OLD."updated_at"); RETURN NULL;',  # noqa: E501
+                    hash="c112d8f78e576e8fc9a895c72a92567c20b093a4",
+                    operation="DELETE",
+                    pgid="pgtrigger_delete_delete_42ea6",
+                    table="tests_ignoreautofieldssnapshotmodel",
+                    when="AFTER",
+                ),
+            ),
+        ),
+    ]

pghistory/tests/models.py

@@ -18,6 +18,14 @@ class BigAutoFieldModel(models.Model):
     id = models.BigAutoField(primary_key=True)
 
 
+class CustomAutoFieldModel(models.Model):
+    id = models.AutoField(primary_key=True, db_column="pk_id")
+
+
+class CustomBigAutoFieldModel(models.Model):
+    id = models.BigAutoField(primary_key=True, db_column="pk_id")
+
+
 @pghistory.track(context_field=pghistory.ContextJSONField())
 @pghistory.track(
     pghistory.InsertEvent("snapshot_no_id_insert"),

pghistory/tests/test_core.py

@@ -28,6 +28,12 @@ def test_generate_history_field(settings):
     field = pghistory.core._generate_history_field(test_models.BigAutoFieldModel, "id")
     assert isinstance(field, models.BigIntegerField)
 
+    # AutoField and BigAutoField should take a custom column name from the original
+    field = pghistory.core._generate_history_field(test_models.CustomAutoFieldModel, "id")
+    assert field.db_column == "pk_id"
+    field = pghistory.core._generate_history_field(test_models.CustomBigAutoFieldModel, "id")
+    assert field.db_column == "pk_id"
+
 
 @pytest.mark.django_db
 def test_image_field_snapshot():