From 126feccc1ca3fc14b8a59505f05a646c3e88a77f Mon Sep 17 00:00:00 2001
From: Tony Wang <wwwjfy@gmail.com>
Date: Sun, 21 Oct 2018 23:29:23 +0800
Subject: [PATCH 1/3] add tests to demonstrate queries using alias

- multiple models are in one subquery
- aggregation functions are used in queries
---
 gino/loader.py       |  3 +++
 tests/test_loader.py | 50 ++++++++++++++++++++++++++++++++++++++++----
 2 files changed, 49 insertions(+), 4 deletions(-)

diff --git a/gino/loader.py b/gino/loader.py
index 9cec1114..b565c700 100644
--- a/gino/loader.py
+++ b/gino/loader.py
@@ -2,6 +2,7 @@
 
 from sqlalchemy import select
 from sqlalchemy.schema import Column
+from sqlalchemy.sql.elements import Label
 
 from .declarative import Model
 
@@ -19,6 +20,8 @@ def get(cls, value):
             rv = AliasLoader(value)
         elif isinstance(value, Column):
             rv = ColumnLoader(value)
+        elif isinstance(value, Label):
+            rv = ColumnLoader(value.name)
         elif isinstance(value, tuple):
             rv = TupleLoader(value)
         elif callable(value):
diff --git a/tests/test_loader.py b/tests/test_loader.py
index 3d001ce1..0d17d510 100644
--- a/tests/test_loader.py
+++ b/tests/test_loader.py
@@ -1,10 +1,12 @@
 import random
 from datetime import datetime
 
-import pytest
 from async_generator import yield_, async_generator
+import pytest
+from sqlalchemy import select
+from sqlalchemy.sql.functions import count
 
-from gino.loader import AliasLoader
+from gino.loader import AliasLoader, ColumnLoader
 from .models import db, User, Team, Company
 
 pytestmark = pytest.mark.asyncio
@@ -12,11 +14,11 @@
 
 @pytest.fixture
 @async_generator
-async def user(bind, random_name):
+async def user(bind):
     c = await Company.create()
     t1 = await Team.create(company_id=c.id)
     t2 = await Team.create(company_id=c.id, parent_id=t1.id)
-    u = await User.create(nickname=random_name, team_id=t2.id)
+    u = await User.create(team_id=t2.id)
     u.team = t2
     t2.parent = t1
     t2.company = c
@@ -161,6 +163,46 @@ async def test_alias_loader_columns(user):
     assert u.id is not None
 
 
+async def test_multiple_models_in_one_query(bind):
+    for _ in range(3):
+        await User.create()
+
+    ua1 = User.alias()
+    ua2 = User.alias()
+    join_query = select([ua1, ua2]).where(ua1.id < ua2.id)
+    result = await join_query.gino.load((ua1.load('id'), ua2.load('id'))).all()
+    assert len(result) == 3
+    for u1, u2 in result:
+        assert u1.id is not None
+        assert u2.id is not None
+        assert u1.id < u2.id
+
+
+async def test_loader_with_aggregation(user):
+    user_count = select(
+        [User.team_id, count().label('count')]
+    ).group_by(
+        User.team_id
+    ).alias()
+    query = Team.outerjoin(user_count).select()
+    result = await query.gino.load(
+        (Team.id, Team.name, user_count.columns.team_id, ColumnLoader('count'))
+    ).all()
+    assert len(result) == 2
+    # team 1 doesn't have users, team 2 has 1 user
+    # third and forth columns are None for team 1
+    for team_id, team_name, user_team_id, user_count in result:
+        if team_id == user.team_id:
+            assert team_name == user.team.name
+            assert user_team_id == user.team_id
+            assert user_count == 1
+        else:
+            assert team_id is not None
+            assert team_name is not None
+            assert user_team_id is None
+            assert user_count is None
+
+
 async def test_adjacency_list_query_builder(user):
     group = Team.alias()
     u = await User.load(team=Team.load(parent=group.on(

From a282cd2d1f41e292470fb6e096835a160997ef97 Mon Sep 17 00:00:00 2001
From: Tony Wang <wwwjfy@gmail.com>
Date: Tue, 23 Oct 2018 00:13:38 +0800
Subject: [PATCH 2/3] update to use Label to cover changed code in test

---
 tests/test_loader.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tests/test_loader.py b/tests/test_loader.py
index 0d17d510..b6a492bc 100644
--- a/tests/test_loader.py
+++ b/tests/test_loader.py
@@ -179,14 +179,15 @@ async def test_multiple_models_in_one_query(bind):
 
 
 async def test_loader_with_aggregation(user):
+    count_col = count().label('count')
     user_count = select(
-        [User.team_id, count().label('count')]
+        [User.team_id, count_col]
     ).group_by(
         User.team_id
     ).alias()
     query = Team.outerjoin(user_count).select()
     result = await query.gino.load(
-        (Team.id, Team.name, user_count.columns.team_id, ColumnLoader('count'))
+        (Team.id, Team.name, user_count.columns.team_id, count_col)
     ).all()
     assert len(result) == 2
     # team 1 doesn't have users, team 2 has 1 user

From be1f37c8c6471791d7e7b13ba81f096df015c023 Mon Sep 17 00:00:00 2001
From: Tony Wang <wwwjfy@gmail.com>
Date: Tue, 23 Oct 2018 11:30:26 +0800
Subject: [PATCH 3/3] remove unused import

---
 tests/test_loader.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/test_loader.py b/tests/test_loader.py
index b6a492bc..30b6b2ae 100644
--- a/tests/test_loader.py
+++ b/tests/test_loader.py
@@ -6,7 +6,7 @@
 from sqlalchemy import select
 from sqlalchemy.sql.functions import count
 
-from gino.loader import AliasLoader, ColumnLoader
+from gino.loader import AliasLoader
 from .models import db, User, Team, Company
 
 pytestmark = pytest.mark.asyncio