From 2df178f4e1a7d8e0c3a92533aa7a10bb51f677ab Mon Sep 17 00:00:00 2001
From: mpeltriaux <Michel_Peltriaux@web.de>
Date: Sun, 10 May 2026 09:21:36 +0200
Subject: [PATCH] # API model extension

* adds model ExternalIdentifier to support linking between external ids and internal ids
---
 api/migrations/0004_externalidentifier.py | 23 ++++++++++++++++
 api/models/__init__.py                    |  3 ++-
 api/models/external_identifier.py         | 33 +++++++++++++++++++++++
 3 files changed, 58 insertions(+), 1 deletion(-)
 create mode 100644 api/migrations/0004_externalidentifier.py
 create mode 100644 api/models/external_identifier.py

diff --git a/api/migrations/0004_externalidentifier.py b/api/migrations/0004_externalidentifier.py
new file mode 100644
index 00000000..9de36dde
--- /dev/null
+++ b/api/migrations/0004_externalidentifier.py
@@ -0,0 +1,23 @@
+# Generated by Django 6.0.5 on 2026-05-10 07:18
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('api', '0003_oauthtoken'),
+        ('user', '0010_user_sso_identifier'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='ExternalIdentifier',
+            fields=[
+                ('external_id', models.CharField(db_comment='Identifier from a source system', max_length=255, primary_key=True, serialize=False)),
+                ('internal_id', models.UUIDField(db_comment='Identifier in konova')),
+                ('created', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='+', to='user.useractionlogentry')),
+            ],
+        ),
+    ]
diff --git a/api/models/__init__.py b/api/models/__init__.py
index d43f0c4e..ca25c99c 100644
--- a/api/models/__init__.py
+++ b/api/models/__init__.py
@@ -5,4 +5,5 @@ Contact: michel.peltriaux@sgdnord.rlp.de
 Created on: 21.01.22
 
 """
-from .token import *
\ No newline at end of file
+from .token import *
+from .external_identifier import *
\ No newline at end of file
diff --git a/api/models/external_identifier.py b/api/models/external_identifier.py
new file mode 100644
index 00000000..597197f7
--- /dev/null
+++ b/api/models/external_identifier.py
@@ -0,0 +1,33 @@
+"""
+Author: Michel Peltriaux
+Created on: 10.05.26
+
+"""
+from django.db import models
+
+
+class ExternalIdentifier(models.Model):
+    """ Holds a lookup to match a given external identifier against the internal identifier in konova.
+
+    Relevant in cases of API transmitted entries, which are updates using external identifiers instead of
+    the internal ones directly.
+
+    """
+    external_id = models.CharField(
+        max_length=255,
+        primary_key=True,
+        db_comment="Identifier from a source system"
+    )
+    internal_id = models.UUIDField(
+        db_comment="Identifier in konova"
+    )
+    created = models.ForeignKey(
+        "user.UserActionLogEntry",
+        on_delete=models.SET_NULL,
+        null=True,
+        blank=True,
+        related_name='+'
+    )
+
+    def __str__(self):
+        return f"{self.external_id} -> {self.internal_id}"
\ No newline at end of file