feat: Implement model.objects.get_or_create()

docs/tutorial/models.md

@@ -204,6 +204,21 @@ user = UserModel.objects.create(username="hakancelik")
 It is the same as save, but it returns the user.
 
 
+### Get or Create
+
+Get or create method tries to get an existing record from the database.
+If the record does not exist, it creates a new one.
+It returns a tuple of `(instance, created)` where `created` is a boolean indicating whether the record was created.
+
+```python
+user, created = UserModel.objects.get_or_create(username="hakancelik")
+
+if created:
+    print("New user created")
+else:
+    print("Existing user found")
+```
+
 ### All
 
 All method is used to get all data from the database and iterate model instances.

src/pydbm/database/manager.py

@@ -171,6 +171,12 @@ def create(self, **kwargs) -> DbmModel:
 
         return model
 
+    def get_or_create(self, **kwargs) -> tuple[DbmModel, bool]:
+        try:
+            return self.get(**kwargs), False
+        except self.model.DoesNotExists:
+            return self.create(**kwargs), True
+
     def get(self, *, id: str | None = None, **unique_together) -> DbmModel:
         if id is None:
             if self.model._config.unique_together != tuple(unique_together.keys()):

tests/models/test_base.py

@@ -404,3 +404,47 @@ class Model(DbmModel):
     last = Model.objects.last()
     assert last is not None
     assert last.username in ("hakan", "celik")
+
+
+def test_base_get_or_create_creates(teardown_db):
+    class Model(DbmModel):
+        username: str
+
+        class Config:
+            unique_together = ("username",)
+
+    instance, created = Model.objects.get_or_create(username="hakan")
+    assert created is True
+    assert instance.username == "hakan"
+    assert Model.objects.count() == 1
+
+
+def test_base_get_or_create_gets(teardown_db):
+    class Model(DbmModel):
+        username: str
+
+        class Config:
+            unique_together = ("username",)
+
+    Model.objects.create(username="hakan")
+    instance, created = Model.objects.get_or_create(username="hakan")
+    assert created is False
+    assert instance.username == "hakan"
+    assert Model.objects.count() == 1
+
+
+def test_base_get_or_create_multiple_fields(teardown_db):
+    class Model(DbmModel):
+        name: str
+        surname: str
+
+        class Config:
+            unique_together = ("name", "surname")
+
+    instance, created = Model.objects.get_or_create(name="hakan", surname="celik")
+    assert created is True
+
+    instance2, created2 = Model.objects.get_or_create(name="hakan", surname="celik")
+    assert created2 is False
+    assert instance.id == instance2.id
+    assert Model.objects.count() == 1