add _columns to Model.update()

tests/test_model_methods/test_update.py

@@ -0,0 +1,111 @@
+from typing import Optional
+
+import databases
+import pytest
+import sqlalchemy
+
+import ormar
+from tests.settings import DATABASE_URL
+
+database = databases.Database(DATABASE_URL, force_rollback=True)
+metadata = sqlalchemy.MetaData()
+
+
+class Director(ormar.Model):
+    class Meta:
+        tablename = "directors"
+        metadata = metadata
+        database = database
+
+    id: int = ormar.Integer(primary_key=True)
+    name: str = ormar.String(max_length=100, nullable=False, name="first_name")
+    last_name: str = ormar.String(max_length=100, nullable=False, name="last_name")
+
+
+class Movie(ormar.Model):
+    class Meta:
+        tablename = "movies"
+        metadata = metadata
+        database = database
+
+    id: int = ormar.Integer(primary_key=True)
+    name: str = ormar.String(max_length=100, nullable=False, name="title")
+    year: int = ormar.Integer()
+    profit: float = ormar.Float()
+    director: Optional[Director] = ormar.ForeignKey(Director)
+
+
+@pytest.fixture(autouse=True, scope="module")
+def create_test_database():
+    engine = sqlalchemy.create_engine(DATABASE_URL)
+    metadata.drop_all(engine)
+    metadata.create_all(engine)
+    yield
+    metadata.drop_all(engine)
+
+
+@pytest.mark.asyncio
+async def test_updating_selected_columns():
+    async with database:
+        director1 = await Director(name="Peter", last_name="Jackson").save()
+        director2 = await Director(name="James", last_name="Cameron").save()
+
+        lotr = await Movie(
+            name="LOTR", year=2001, director=director1, profit=1.140
+        ).save()
+
+        lotr.name = "Lord of The Rings"
+        lotr.year = 2003
+        lotr.profit = 1.212
+
+        await lotr.update(_columns=["name"])
+
+        # before reload the field has current value even if not saved
+        assert lotr.year == 2003
+
+        lotr = await Movie.objects.get()
+        assert lotr.name == "Lord of The Rings"
+        assert lotr.year == 2001
+        assert round(lotr.profit, 3) == 1.140
+        assert lotr.director.pk == director1.pk
+
+        lotr.year = 2003
+        lotr.profit = 1.212
+        lotr.director = director2
+
+        await lotr.update(_columns=["year", "profit"])
+        lotr = await Movie.objects.get()
+        assert lotr.year == 2003
+        assert round(lotr.profit, 3) == 1.212
+        assert lotr.director.pk == director1.pk
+
+
+@pytest.mark.asyncio
+async def test_not_passing_columns_or_empty_list_saves_all():
+    async with database:
+        director = await Director(name="James", last_name="Cameron").save()
+        terminator = await Movie(
+            name="Terminator", year=1984, director=director, profit=0.078
+        ).save()
+
+        terminator.name = "Terminator 2"
+        terminator.year = 1991
+        terminator.profit = 0.520
+
+        await terminator.update(_columns=[])
+
+        terminator = await Movie.objects.get()
+        assert terminator.name == "Terminator 2"
+        assert terminator.year == 1991
+        assert round(terminator.profit, 3) == 0.520
+
+        terminator.name = "Terminator 3"
+        terminator.year = 2003
+        terminator.profit = 0.433
+
+        await terminator.update()
+
+        terminator = await terminator.load()
+        assert terminator.name == "Terminator 3"
+        assert terminator.year == 2003
+        assert round(terminator.profit, 3) == 0.433