From e6cae73e32375da2e8e97a49083ad31471a70603 Mon Sep 17 00:00:00 2001
From: Take Weiland <diesieben07@gmail.com>
Date: Sun, 15 Dec 2024 17:31:58 +0100
Subject: [PATCH 01/12] fix(optimizer): Prevent issuing duplicated queries for
 certain uses of first() and get()

---
 strawberry_django/fields/field.py |  23 +++++
 tests/projects/schema.py          |   2 +
 tests/test_optimizer.py           | 149 +++++++++++++++++++++++++++++-
 3 files changed, 171 insertions(+), 3 deletions(-)

diff --git a/strawberry_django/fields/field.py b/strawberry_django/fields/field.py
index 56b4cd86..ba3c9a87 100644
--- a/strawberry_django/fields/field.py
+++ b/strawberry_django/fields/field.py
@@ -282,12 +282,35 @@ def qs_hook(qs: models.QuerySet):  # type: ignore
 
             def qs_hook(qs: models.QuerySet):  # type: ignore
                 qs = self.get_queryset(qs, info, **kwargs)
+                # Don't use qs.first() if the queryset is optimized by prefetching.
+                # Calling first in that case would disregard the prefetched results, because first implicitly
+                # adds a limit to the query
+                if is_optimized_by_prefetching(qs):
+                    return next(iter(qs), None)
                 return qs.first()
 
         else:
 
             def qs_hook(qs: models.QuerySet):
                 qs = self.get_queryset(qs, info, **kwargs)
+                # See comment above about qs.first(), the same applies for get()
+                if is_optimized_by_prefetching(qs):
+                    # mimic behavior of get()
+                    qs_len = len(qs)  # the queryset is already prefetched, no issue with just using len()
+                    if qs_len == 0:
+                        raise qs.model.DoesNotExist(
+                            "%s matching query does not exist." % qs.model._meta.object_name
+                        )
+                    elif qs_len != 1:
+                        raise qs.model.MultipleObjectsReturned(
+                            "get() returned more than one %s -- it returned %s!"
+                            % (
+                                qs.model._meta.object_name,
+                                qs_len,
+                            )
+                        )
+                    else:
+                        return qs[0]
                 return qs.get()
 
         return qs_hook
diff --git a/tests/projects/schema.py b/tests/projects/schema.py
index 669ab286..b44de907 100644
--- a/tests/projects/schema.py
+++ b/tests/projects/schema.py
@@ -169,6 +169,8 @@ class MilestoneType(relay.Node, Named):
             filters=IssueFilter,
         )
     )
+    first_issue: Optional["IssueType"] = strawberry_django.field(field_name="issues")
+    first_issue_required: "IssueType" = strawberry_django.field(field_name="issues")
 
     @strawberry_django.field(
         prefetch_related=[
diff --git a/tests/test_optimizer.py b/tests/test_optimizer.py
index f4ff56a1..1142030b 100644
--- a/tests/test_optimizer.py
+++ b/tests/test_optimizer.py
@@ -6,12 +6,12 @@
 from django.db.models import Prefetch
 from django.utils import timezone
 from pytest_mock import MockerFixture
-from strawberry.relay import to_base64
-from strawberry.types import ExecutionResult
+from strawberry.relay import to_base64, GlobalID
+from strawberry.types import ExecutionResult, get_object_definition
 
 import strawberry_django
 from strawberry_django.optimizer import DjangoOptimizerExtension
-from tests.projects.schema import StaffType
+from tests.projects.schema import StaffType, MilestoneType, IssueType
 
 from . import utils
 from .projects.faker import (
@@ -1605,3 +1605,146 @@ def test_query_paginated_nested(db, gql_client: GraphQLTestClient):
             },
         ]
     }
+
+
+@pytest.mark.django_db(transaction=True)
+def test_prefetch_multi_field_single_optional(
+        db, gql_client: GraphQLTestClient
+):
+
+    milestone1 = MilestoneFactory.create()
+    milestone2 = MilestoneFactory.create()
+
+    issue = IssueFactory.create(name="Foo", milestone=milestone1)
+    issue_id = str(GlobalID(get_object_definition(IssueType).name, str(issue.id)))
+
+    milestone_id_1 = str(GlobalID(get_object_definition(MilestoneType).name, str(milestone1.id)))
+    milestone_id_2 = str(GlobalID(get_object_definition(MilestoneType).name, str(milestone2.id)))
+
+    query = """\
+      query TestQuery($id1: GlobalID!, $id2: GlobalID!) {
+        a: milestone(id: $id1) {
+          firstIssue {
+            id
+          }
+        }
+        b: milestone(id: $id2) {
+          firstIssue {
+            id
+          }
+        }
+      }
+    """
+
+    with assert_num_queries(4):
+        res = gql_client.query(query, variables={"id1": milestone_id_1, "id2": milestone_id_2})
+
+    assert res.errors is None
+    assert res.data == {
+        "a": {
+            "firstIssue": {
+                "id": issue_id,
+            },
+        },
+        "b": {
+            "firstIssue": None,
+        },
+    }
+
+
+@pytest.mark.django_db(transaction=True)
+def test_prefetch_multi_field_single_required(
+        db, gql_client: GraphQLTestClient
+):
+    milestone = MilestoneFactory.create()
+
+    issue = IssueFactory.create(name="Foo", milestone=milestone)
+    issue_id = str(GlobalID(get_object_definition(IssueType).name, str(issue.id)))
+
+    milestone_id = str(GlobalID(get_object_definition(MilestoneType).name, str(milestone.id)))
+
+    query = """\
+      query TestQuery($id: GlobalID!) {
+        milestone(id: $id) {
+          firstIssueRequired {
+            id
+          }
+        }
+      }
+    """
+
+    with assert_num_queries(2):
+        res = gql_client.query(query, variables={"id": milestone_id})
+
+    assert res.errors is None
+    assert res.data == {
+        "milestone": {
+            "firstIssueRequired": {
+                "id": issue_id,
+            },
+        },
+    }
+
+
+@pytest.mark.django_db(transaction=True)
+def test_prefetch_multi_field_single_required_missing(
+        db, gql_client: GraphQLTestClient
+):
+    milestone1 = MilestoneFactory.create()
+
+    milestone_id = str(GlobalID(get_object_definition(MilestoneType).name, str(milestone1.id)))
+
+    query = """\
+      query TestQuery($id: GlobalID!) {
+        milestone(id: $id) {
+          firstIssueRequired {
+            id
+          }
+        }
+      }
+    """
+
+    with assert_num_queries(2):
+        res = gql_client.query(query, variables={"id": milestone_id}, assert_no_errors=False)
+
+    assert res.errors is not None
+    assert res.errors == [
+        {
+            "locations": [{"column": 11, "line": 3}],
+            "message": "Issue matching query does not exist.",
+            "path": ["milestone", "firstIssueRequired"],
+        }
+    ]
+
+
+@pytest.mark.django_db(transaction=True)
+def test_prefetch_multi_field_single_required_multiple_returned(
+        db, gql_client: GraphQLTestClient
+):
+    milestone = MilestoneFactory.create()
+
+    milestone_id = str(GlobalID(get_object_definition(MilestoneType).name, str(milestone.id)))
+    IssueFactory.create(name="Foo", milestone=milestone)
+    IssueFactory.create(name="Bar", milestone=milestone)
+
+    query = """\
+      query TestQuery($id: GlobalID!) {
+        milestone(id: $id) {
+          firstIssueRequired {
+            id
+          }
+        }
+      }
+    """
+
+    with assert_num_queries(2):
+        res = gql_client.query(query, variables={"id": milestone_id}, assert_no_errors=False)
+
+    assert res.errors is not None
+    assert res.errors == [
+        {
+            "locations": [{"column": 11, "line": 3}],
+            "message": "get() returned more than one Issue -- it returned 2!",
+            "path": ["milestone", "firstIssueRequired"],
+        }
+    ]

From 04b7744a1c68b439642bdda16116942d1df9ace1 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Sun, 15 Dec 2024 16:39:10 +0000
Subject: [PATCH 02/12] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 strawberry_django/fields/field.py | 12 ++++----
 tests/test_optimizer.py           | 49 +++++++++++++++++++------------
 2 files changed, 37 insertions(+), 24 deletions(-)

diff --git a/strawberry_django/fields/field.py b/strawberry_django/fields/field.py
index ba3c9a87..6faebbb7 100644
--- a/strawberry_django/fields/field.py
+++ b/strawberry_django/fields/field.py
@@ -296,12 +296,15 @@ def qs_hook(qs: models.QuerySet):
                 # See comment above about qs.first(), the same applies for get()
                 if is_optimized_by_prefetching(qs):
                     # mimic behavior of get()
-                    qs_len = len(qs)  # the queryset is already prefetched, no issue with just using len()
+                    qs_len = len(
+                        qs
+                    )  # the queryset is already prefetched, no issue with just using len()
                     if qs_len == 0:
                         raise qs.model.DoesNotExist(
-                            "%s matching query does not exist." % qs.model._meta.object_name
+                            "%s matching query does not exist."
+                            % qs.model._meta.object_name
                         )
-                    elif qs_len != 1:
+                    if qs_len != 1:
                         raise qs.model.MultipleObjectsReturned(
                             "get() returned more than one %s -- it returned %s!"
                             % (
@@ -309,8 +312,7 @@ def qs_hook(qs: models.QuerySet):
                                 qs_len,
                             )
                         )
-                    else:
-                        return qs[0]
+                    return qs[0]
                 return qs.get()
 
         return qs_hook
diff --git a/tests/test_optimizer.py b/tests/test_optimizer.py
index 1142030b..1d525952 100644
--- a/tests/test_optimizer.py
+++ b/tests/test_optimizer.py
@@ -6,12 +6,12 @@
 from django.db.models import Prefetch
 from django.utils import timezone
 from pytest_mock import MockerFixture
-from strawberry.relay import to_base64, GlobalID
+from strawberry.relay import GlobalID, to_base64
 from strawberry.types import ExecutionResult, get_object_definition
 
 import strawberry_django
 from strawberry_django.optimizer import DjangoOptimizerExtension
-from tests.projects.schema import StaffType, MilestoneType, IssueType
+from tests.projects.schema import IssueType, MilestoneType, StaffType
 
 from . import utils
 from .projects.faker import (
@@ -1608,18 +1608,19 @@ def test_query_paginated_nested(db, gql_client: GraphQLTestClient):
 
 
 @pytest.mark.django_db(transaction=True)
-def test_prefetch_multi_field_single_optional(
-        db, gql_client: GraphQLTestClient
-):
-
+def test_prefetch_multi_field_single_optional(db, gql_client: GraphQLTestClient):
     milestone1 = MilestoneFactory.create()
     milestone2 = MilestoneFactory.create()
 
     issue = IssueFactory.create(name="Foo", milestone=milestone1)
     issue_id = str(GlobalID(get_object_definition(IssueType).name, str(issue.id)))
 
-    milestone_id_1 = str(GlobalID(get_object_definition(MilestoneType).name, str(milestone1.id)))
-    milestone_id_2 = str(GlobalID(get_object_definition(MilestoneType).name, str(milestone2.id)))
+    milestone_id_1 = str(
+        GlobalID(get_object_definition(MilestoneType).name, str(milestone1.id))
+    )
+    milestone_id_2 = str(
+        GlobalID(get_object_definition(MilestoneType).name, str(milestone2.id))
+    )
 
     query = """\
       query TestQuery($id1: GlobalID!, $id2: GlobalID!) {
@@ -1637,7 +1638,9 @@ def test_prefetch_multi_field_single_optional(
     """
 
     with assert_num_queries(4):
-        res = gql_client.query(query, variables={"id1": milestone_id_1, "id2": milestone_id_2})
+        res = gql_client.query(
+            query, variables={"id1": milestone_id_1, "id2": milestone_id_2}
+        )
 
     assert res.errors is None
     assert res.data == {
@@ -1653,15 +1656,15 @@ def test_prefetch_multi_field_single_optional(
 
 
 @pytest.mark.django_db(transaction=True)
-def test_prefetch_multi_field_single_required(
-        db, gql_client: GraphQLTestClient
-):
+def test_prefetch_multi_field_single_required(db, gql_client: GraphQLTestClient):
     milestone = MilestoneFactory.create()
 
     issue = IssueFactory.create(name="Foo", milestone=milestone)
     issue_id = str(GlobalID(get_object_definition(IssueType).name, str(issue.id)))
 
-    milestone_id = str(GlobalID(get_object_definition(MilestoneType).name, str(milestone.id)))
+    milestone_id = str(
+        GlobalID(get_object_definition(MilestoneType).name, str(milestone.id))
+    )
 
     query = """\
       query TestQuery($id: GlobalID!) {
@@ -1688,11 +1691,13 @@ def test_prefetch_multi_field_single_required(
 
 @pytest.mark.django_db(transaction=True)
 def test_prefetch_multi_field_single_required_missing(
-        db, gql_client: GraphQLTestClient
+    db, gql_client: GraphQLTestClient
 ):
     milestone1 = MilestoneFactory.create()
 
-    milestone_id = str(GlobalID(get_object_definition(MilestoneType).name, str(milestone1.id)))
+    milestone_id = str(
+        GlobalID(get_object_definition(MilestoneType).name, str(milestone1.id))
+    )
 
     query = """\
       query TestQuery($id: GlobalID!) {
@@ -1705,7 +1710,9 @@ def test_prefetch_multi_field_single_required_missing(
     """
 
     with assert_num_queries(2):
-        res = gql_client.query(query, variables={"id": milestone_id}, assert_no_errors=False)
+        res = gql_client.query(
+            query, variables={"id": milestone_id}, assert_no_errors=False
+        )
 
     assert res.errors is not None
     assert res.errors == [
@@ -1719,11 +1726,13 @@ def test_prefetch_multi_field_single_required_missing(
 
 @pytest.mark.django_db(transaction=True)
 def test_prefetch_multi_field_single_required_multiple_returned(
-        db, gql_client: GraphQLTestClient
+    db, gql_client: GraphQLTestClient
 ):
     milestone = MilestoneFactory.create()
 
-    milestone_id = str(GlobalID(get_object_definition(MilestoneType).name, str(milestone.id)))
+    milestone_id = str(
+        GlobalID(get_object_definition(MilestoneType).name, str(milestone.id))
+    )
     IssueFactory.create(name="Foo", milestone=milestone)
     IssueFactory.create(name="Bar", milestone=milestone)
 
@@ -1738,7 +1747,9 @@ def test_prefetch_multi_field_single_required_multiple_returned(
     """
 
     with assert_num_queries(2):
-        res = gql_client.query(query, variables={"id": milestone_id}, assert_no_errors=False)
+        res = gql_client.query(
+            query, variables={"id": milestone_id}, assert_no_errors=False
+        )
 
     assert res.errors is not None
     assert res.errors == [

From 7cc709fb517597177607045282c2d94f16764a7b Mon Sep 17 00:00:00 2001
From: Take Weiland <diesieben07@gmail.com>
Date: Sun, 15 Dec 2024 17:31:58 +0100
Subject: [PATCH 03/12] fix(optimizer): Prevent issuing duplicated queries for
 certain uses of first() and get()

---
 strawberry_django/fields/field.py |  23 +++++
 tests/projects/schema.py          |   2 +
 tests/test_optimizer.py           | 149 +++++++++++++++++++++++++++++-
 3 files changed, 171 insertions(+), 3 deletions(-)

diff --git a/strawberry_django/fields/field.py b/strawberry_django/fields/field.py
index 56b4cd86..ba3c9a87 100644
--- a/strawberry_django/fields/field.py
+++ b/strawberry_django/fields/field.py
@@ -282,12 +282,35 @@ def qs_hook(qs: models.QuerySet):  # type: ignore
 
             def qs_hook(qs: models.QuerySet):  # type: ignore
                 qs = self.get_queryset(qs, info, **kwargs)
+                # Don't use qs.first() if the queryset is optimized by prefetching.
+                # Calling first in that case would disregard the prefetched results, because first implicitly
+                # adds a limit to the query
+                if is_optimized_by_prefetching(qs):
+                    return next(iter(qs), None)
                 return qs.first()
 
         else:
 
             def qs_hook(qs: models.QuerySet):
                 qs = self.get_queryset(qs, info, **kwargs)
+                # See comment above about qs.first(), the same applies for get()
+                if is_optimized_by_prefetching(qs):
+                    # mimic behavior of get()
+                    qs_len = len(qs)  # the queryset is already prefetched, no issue with just using len()
+                    if qs_len == 0:
+                        raise qs.model.DoesNotExist(
+                            "%s matching query does not exist." % qs.model._meta.object_name
+                        )
+                    elif qs_len != 1:
+                        raise qs.model.MultipleObjectsReturned(
+                            "get() returned more than one %s -- it returned %s!"
+                            % (
+                                qs.model._meta.object_name,
+                                qs_len,
+                            )
+                        )
+                    else:
+                        return qs[0]
                 return qs.get()
 
         return qs_hook
diff --git a/tests/projects/schema.py b/tests/projects/schema.py
index 669ab286..b44de907 100644
--- a/tests/projects/schema.py
+++ b/tests/projects/schema.py
@@ -169,6 +169,8 @@ class MilestoneType(relay.Node, Named):
             filters=IssueFilter,
         )
     )
+    first_issue: Optional["IssueType"] = strawberry_django.field(field_name="issues")
+    first_issue_required: "IssueType" = strawberry_django.field(field_name="issues")
 
     @strawberry_django.field(
         prefetch_related=[
diff --git a/tests/test_optimizer.py b/tests/test_optimizer.py
index f4ff56a1..21d6c770 100644
--- a/tests/test_optimizer.py
+++ b/tests/test_optimizer.py
@@ -6,12 +6,12 @@
 from django.db.models import Prefetch
 from django.utils import timezone
 from pytest_mock import MockerFixture
-from strawberry.relay import to_base64
-from strawberry.types import ExecutionResult
+from strawberry.relay import to_base64, GlobalID
+from strawberry.types import ExecutionResult, get_object_definition
 
 import strawberry_django
 from strawberry_django.optimizer import DjangoOptimizerExtension
-from tests.projects.schema import StaffType
+from tests.projects.schema import StaffType, MilestoneType, IssueType
 
 from . import utils
 from .projects.faker import (
@@ -1605,3 +1605,146 @@ def test_query_paginated_nested(db, gql_client: GraphQLTestClient):
             },
         ]
     }
+
+
+@pytest.mark.django_db(transaction=True)
+def test_prefetch_multi_field_single_optional(
+        db, gql_client: GraphQLTestClient
+):
+
+    milestone1 = MilestoneFactory.create()
+    milestone2 = MilestoneFactory.create()
+
+    issue = IssueFactory.create(name="Foo", milestone=milestone1)
+    issue_id = str(GlobalID(get_object_definition(IssueType, strict=True).name, str(issue.id)))
+
+    milestone_id_1 = str(GlobalID(get_object_definition(MilestoneType, strict=True).name, str(milestone1.id)))
+    milestone_id_2 = str(GlobalID(get_object_definition(MilestoneType, strict=True).name, str(milestone2.id)))
+
+    query = """\
+      query TestQuery($id1: GlobalID!, $id2: GlobalID!) {
+        a: milestone(id: $id1) {
+          firstIssue {
+            id
+          }
+        }
+        b: milestone(id: $id2) {
+          firstIssue {
+            id
+          }
+        }
+      }
+    """
+
+    with assert_num_queries(4):
+        res = gql_client.query(query, variables={"id1": milestone_id_1, "id2": milestone_id_2})
+
+    assert res.errors is None
+    assert res.data == {
+        "a": {
+            "firstIssue": {
+                "id": issue_id,
+            },
+        },
+        "b": {
+            "firstIssue": None,
+        },
+    }
+
+
+@pytest.mark.django_db(transaction=True)
+def test_prefetch_multi_field_single_required(
+        db, gql_client: GraphQLTestClient
+):
+    milestone = MilestoneFactory.create()
+
+    issue = IssueFactory.create(name="Foo", milestone=milestone)
+    issue_id = str(GlobalID(get_object_definition(IssueType, strict=True).name, str(issue.id)))
+
+    milestone_id = str(GlobalID(get_object_definition(MilestoneType, strict=True).name, str(milestone.id)))
+
+    query = """\
+      query TestQuery($id: GlobalID!) {
+        milestone(id: $id) {
+          firstIssueRequired {
+            id
+          }
+        }
+      }
+    """
+
+    with assert_num_queries(2):
+        res = gql_client.query(query, variables={"id": milestone_id})
+
+    assert res.errors is None
+    assert res.data == {
+        "milestone": {
+            "firstIssueRequired": {
+                "id": issue_id,
+            },
+        },
+    }
+
+
+@pytest.mark.django_db(transaction=True)
+def test_prefetch_multi_field_single_required_missing(
+        db, gql_client: GraphQLTestClient
+):
+    milestone1 = MilestoneFactory.create()
+
+    milestone_id = str(GlobalID(get_object_definition(MilestoneType, strict=True).name, str(milestone1.id)))
+
+    query = """\
+      query TestQuery($id: GlobalID!) {
+        milestone(id: $id) {
+          firstIssueRequired {
+            id
+          }
+        }
+      }
+    """
+
+    with assert_num_queries(2):
+        res = gql_client.query(query, variables={"id": milestone_id}, assert_no_errors=False)
+
+    assert res.errors is not None
+    assert res.errors == [
+        {
+            "locations": [{"column": 11, "line": 3}],
+            "message": "Issue matching query does not exist.",
+            "path": ["milestone", "firstIssueRequired"],
+        }
+    ]
+
+
+@pytest.mark.django_db(transaction=True)
+def test_prefetch_multi_field_single_required_multiple_returned(
+        db, gql_client: GraphQLTestClient
+):
+    milestone = MilestoneFactory.create()
+
+    milestone_id = str(GlobalID(get_object_definition(MilestoneType, strict=True).name, str(milestone.id)))
+    IssueFactory.create(name="Foo", milestone=milestone)
+    IssueFactory.create(name="Bar", milestone=milestone)
+
+    query = """\
+      query TestQuery($id: GlobalID!) {
+        milestone(id: $id) {
+          firstIssueRequired {
+            id
+          }
+        }
+      }
+    """
+
+    with assert_num_queries(2):
+        res = gql_client.query(query, variables={"id": milestone_id}, assert_no_errors=False)
+
+    assert res.errors is not None
+    assert res.errors == [
+        {
+            "locations": [{"column": 11, "line": 3}],
+            "message": "get() returned more than one Issue -- it returned 2!",
+            "path": ["milestone", "firstIssueRequired"],
+        }
+    ]

From ed74cf57ddc856666ffa79f4181b3431fdf0df86 Mon Sep 17 00:00:00 2001
From: Take Weiland <diesieben07@gmail.com>
Date: Sun, 15 Dec 2024 17:45:04 +0100
Subject: [PATCH 04/12] fix typing issue

---
 tests/test_optimizer.py | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/tests/test_optimizer.py b/tests/test_optimizer.py
index 1d525952..dc90ffab 100644
--- a/tests/test_optimizer.py
+++ b/tests/test_optimizer.py
@@ -1613,13 +1613,13 @@ def test_prefetch_multi_field_single_optional(db, gql_client: GraphQLTestClient)
     milestone2 = MilestoneFactory.create()
 
     issue = IssueFactory.create(name="Foo", milestone=milestone1)
-    issue_id = str(GlobalID(get_object_definition(IssueType).name, str(issue.id)))
+    issue_id = str(GlobalID(get_object_definition(IssueType, strict=True).name, str(issue.id)))
 
     milestone_id_1 = str(
-        GlobalID(get_object_definition(MilestoneType).name, str(milestone1.id))
+        GlobalID(get_object_definition(MilestoneType, strict=True).name, str(milestone1.id))
     )
     milestone_id_2 = str(
-        GlobalID(get_object_definition(MilestoneType).name, str(milestone2.id))
+        GlobalID(get_object_definition(MilestoneType, strict=True).name, str(milestone2.id))
     )
 
     query = """\
@@ -1660,10 +1660,10 @@ def test_prefetch_multi_field_single_required(db, gql_client: GraphQLTestClient)
     milestone = MilestoneFactory.create()
 
     issue = IssueFactory.create(name="Foo", milestone=milestone)
-    issue_id = str(GlobalID(get_object_definition(IssueType).name, str(issue.id)))
+    issue_id = str(GlobalID(get_object_definition(IssueType, strict=True).name, str(issue.id)))
 
     milestone_id = str(
-        GlobalID(get_object_definition(MilestoneType).name, str(milestone.id))
+        GlobalID(get_object_definition(MilestoneType, strict=True).name, str(milestone.id))
     )
 
     query = """\
@@ -1696,7 +1696,7 @@ def test_prefetch_multi_field_single_required_missing(
     milestone1 = MilestoneFactory.create()
 
     milestone_id = str(
-        GlobalID(get_object_definition(MilestoneType).name, str(milestone1.id))
+        GlobalID(get_object_definition(MilestoneType, strict=True).name, str(milestone1.id))
     )
 
     query = """\
@@ -1731,7 +1731,7 @@ def test_prefetch_multi_field_single_required_multiple_returned(
     milestone = MilestoneFactory.create()
 
     milestone_id = str(
-        GlobalID(get_object_definition(MilestoneType).name, str(milestone.id))
+        GlobalID(get_object_definition(MilestoneType, strict=True).name, str(milestone.id))
     )
     IssueFactory.create(name="Foo", milestone=milestone)
     IssueFactory.create(name="Bar", milestone=milestone)

From 27c92b88ff537ac5a4f3e17177413d3c8bc41314 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Sun, 15 Dec 2024 16:45:15 +0000
Subject: [PATCH 05/12] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 tests/test_optimizer.py | 28 +++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/tests/test_optimizer.py b/tests/test_optimizer.py
index dc90ffab..c2274250 100644
--- a/tests/test_optimizer.py
+++ b/tests/test_optimizer.py
@@ -1613,13 +1613,19 @@ def test_prefetch_multi_field_single_optional(db, gql_client: GraphQLTestClient)
     milestone2 = MilestoneFactory.create()
 
     issue = IssueFactory.create(name="Foo", milestone=milestone1)
-    issue_id = str(GlobalID(get_object_definition(IssueType, strict=True).name, str(issue.id)))
+    issue_id = str(
+        GlobalID(get_object_definition(IssueType, strict=True).name, str(issue.id))
+    )
 
     milestone_id_1 = str(
-        GlobalID(get_object_definition(MilestoneType, strict=True).name, str(milestone1.id))
+        GlobalID(
+            get_object_definition(MilestoneType, strict=True).name, str(milestone1.id)
+        )
     )
     milestone_id_2 = str(
-        GlobalID(get_object_definition(MilestoneType, strict=True).name, str(milestone2.id))
+        GlobalID(
+            get_object_definition(MilestoneType, strict=True).name, str(milestone2.id)
+        )
     )
 
     query = """\
@@ -1660,10 +1666,14 @@ def test_prefetch_multi_field_single_required(db, gql_client: GraphQLTestClient)
     milestone = MilestoneFactory.create()
 
     issue = IssueFactory.create(name="Foo", milestone=milestone)
-    issue_id = str(GlobalID(get_object_definition(IssueType, strict=True).name, str(issue.id)))
+    issue_id = str(
+        GlobalID(get_object_definition(IssueType, strict=True).name, str(issue.id))
+    )
 
     milestone_id = str(
-        GlobalID(get_object_definition(MilestoneType, strict=True).name, str(milestone.id))
+        GlobalID(
+            get_object_definition(MilestoneType, strict=True).name, str(milestone.id)
+        )
     )
 
     query = """\
@@ -1696,7 +1706,9 @@ def test_prefetch_multi_field_single_required_missing(
     milestone1 = MilestoneFactory.create()
 
     milestone_id = str(
-        GlobalID(get_object_definition(MilestoneType, strict=True).name, str(milestone1.id))
+        GlobalID(
+            get_object_definition(MilestoneType, strict=True).name, str(milestone1.id)
+        )
     )
 
     query = """\
@@ -1731,7 +1743,9 @@ def test_prefetch_multi_field_single_required_multiple_returned(
     milestone = MilestoneFactory.create()
 
     milestone_id = str(
-        GlobalID(get_object_definition(MilestoneType, strict=True).name, str(milestone.id))
+        GlobalID(
+            get_object_definition(MilestoneType, strict=True).name, str(milestone.id)
+        )
     )
     IssueFactory.create(name="Foo", milestone=milestone)
     IssueFactory.create(name="Bar", milestone=milestone)

From d158018cd20b7733b0e9a2a4d518ddd1753eeaf0 Mon Sep 17 00:00:00 2001
From: Take Weiland <diesieben07@gmail.com>
Date: Sun, 15 Dec 2024 17:53:31 +0100
Subject: [PATCH 06/12] fix schema test

---
 tests/projects/snapshots/schema.gql                  | 4 +++-
 tests/projects/snapshots/schema_with_inheritance.gql | 4 +++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/tests/projects/snapshots/schema.gql b/tests/projects/snapshots/schema.gql
index 26039d01..fe965768 100644
--- a/tests/projects/snapshots/schema.gql
+++ b/tests/projects/snapshots/schema.gql
@@ -399,6 +399,8 @@ type MilestoneType implements Node & Named {
     """Returns the items in the list that come after the specified cursor."""
     last: Int = null
   ): IssueTypeConnection!
+  firstIssue: IssueType
+  firstIssueRequired: IssueType!
   myIssues: [IssueType!]!
   myBugsCount: Int!
   asyncField(value: String!): String!
@@ -969,4 +971,4 @@ input PermDefinition {
   The permission itself. If this is empty that means that we are checking for any permission for the given app.
   """
   permission: String
-}
\ No newline at end of file
+}
diff --git a/tests/projects/snapshots/schema_with_inheritance.gql b/tests/projects/snapshots/schema_with_inheritance.gql
index 2b11dd7d..407c1371 100644
--- a/tests/projects/snapshots/schema_with_inheritance.gql
+++ b/tests/projects/snapshots/schema_with_inheritance.gql
@@ -189,6 +189,8 @@ type MilestoneType implements Node & Named {
     """Returns the items in the list that come after the specified cursor."""
     last: Int = null
   ): IssueTypeConnection!
+  firstIssue: IssueType
+  firstIssueRequired: IssueType!
   myIssues: [IssueType!]!
   myBugsCount: Int!
   asyncField(value: String!): String!
@@ -429,4 +431,4 @@ type UserType implements Node {
   isSuperuser: Boolean!
   isStaff: Boolean!
   fullName: String!
-}
\ No newline at end of file
+}

From 8e69f752bd4961e26bb9111011ba6e262e2f3987 Mon Sep 17 00:00:00 2001
From: Take Weiland <diesieben07@gmail.com>
Date: Sun, 15 Dec 2024 18:05:43 +0100
Subject: [PATCH 07/12] fix schema test

---
 tests/projects/snapshots/schema.gql                  | 2 +-
 tests/projects/snapshots/schema_with_inheritance.gql | 4 +++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/tests/projects/snapshots/schema.gql b/tests/projects/snapshots/schema.gql
index fe965768..61da21ca 100644
--- a/tests/projects/snapshots/schema.gql
+++ b/tests/projects/snapshots/schema.gql
@@ -971,4 +971,4 @@ input PermDefinition {
   The permission itself. If this is empty that means that we are checking for any permission for the given app.
   """
   permission: String
-}
+}
\ No newline at end of file
diff --git a/tests/projects/snapshots/schema_with_inheritance.gql b/tests/projects/snapshots/schema_with_inheritance.gql
index 407c1371..748c1ffd 100644
--- a/tests/projects/snapshots/schema_with_inheritance.gql
+++ b/tests/projects/snapshots/schema_with_inheritance.gql
@@ -219,6 +219,8 @@ type MilestoneTypeSubclass implements Node & Named {
     """Returns the items in the list that come after the specified cursor."""
     last: Int = null
   ): IssueTypeConnection!
+  firstIssue: IssueType
+  firstIssueRequired: IssueType!
   myIssues: [IssueType!]!
   myBugsCount: Int!
   asyncField(value: String!): String!
@@ -431,4 +433,4 @@ type UserType implements Node {
   isSuperuser: Boolean!
   isStaff: Boolean!
   fullName: String!
-}
+}
\ No newline at end of file

From d0ce6b6b4ca34aaefcd212b7c8752621965a052b Mon Sep 17 00:00:00 2001
From: Take Weiland <diesieben07@gmail.com>
Date: Sun, 15 Dec 2024 18:23:56 +0100
Subject: [PATCH 08/12] fix error message formatting

---
 strawberry_django/fields/field.py | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/strawberry_django/fields/field.py b/strawberry_django/fields/field.py
index 6faebbb7..847b1611 100644
--- a/strawberry_django/fields/field.py
+++ b/strawberry_django/fields/field.py
@@ -301,16 +301,11 @@ def qs_hook(qs: models.QuerySet):
                     )  # the queryset is already prefetched, no issue with just using len()
                     if qs_len == 0:
                         raise qs.model.DoesNotExist(
-                            "%s matching query does not exist."
-                            % qs.model._meta.object_name
+                            f"{qs.model._meta.object_name} matching query does not exist."
                         )
                     if qs_len != 1:
                         raise qs.model.MultipleObjectsReturned(
-                            "get() returned more than one %s -- it returned %s!"
-                            % (
-                                qs.model._meta.object_name,
-                                qs_len,
-                            )
+                            f"get() returned more than one {qs.model._meta.object_name} -- it returned {qs_len}!"
                         )
                     return qs[0]
                 return qs.get()

From 3f81116f56f622535cd79a58df108196f5661757 Mon Sep 17 00:00:00 2001
From: Take Weiland <diesieben07@gmail.com>
Date: Tue, 17 Dec 2024 16:30:50 +0100
Subject: [PATCH 09/12] Improve prefetching for single/optional fields by not
 prefetching the whole table

---
 strawberry_django/fields/field.py | 18 ++++++++----------
 strawberry_django/pagination.py   | 14 ++++++++++++++
 2 files changed, 22 insertions(+), 10 deletions(-)

diff --git a/strawberry_django/fields/field.py b/strawberry_django/fields/field.py
index 847b1611..bd70120e 100644
--- a/strawberry_django/fields/field.py
+++ b/strawberry_django/fields/field.py
@@ -31,6 +31,7 @@
     ReverseOneToOneDescriptor,
 )
 from django.db.models.manager import BaseManager
+from django.db.models.query import MAX_GET_RESULTS
 from django.db.models.query_utils import DeferredAttribute
 from strawberry import UNSET, relay
 from strawberry.annotation import StrawberryAnnotation
@@ -282,30 +283,27 @@ def qs_hook(qs: models.QuerySet):  # type: ignore
 
             def qs_hook(qs: models.QuerySet):  # type: ignore
                 qs = self.get_queryset(qs, info, **kwargs)
-                # Don't use qs.first() if the queryset is optimized by prefetching.
-                # Calling first in that case would disregard the prefetched results, because first implicitly
-                # adds a limit to the query
-                if is_optimized_by_prefetching(qs):
-                    return next(iter(qs), None)
                 return qs.first()
 
         else:
 
             def qs_hook(qs: models.QuerySet):
                 qs = self.get_queryset(qs, info, **kwargs)
-                # See comment above about qs.first(), the same applies for get()
+                # Don't use qs.get() if the queryset is optimized by prefetching.
+                # Calling first in that case would disregard the prefetched results, because first implicitly
+                # adds a limit to the query
                 if is_optimized_by_prefetching(qs):
                     # mimic behavior of get()
-                    qs_len = len(
-                        qs
-                    )  # the queryset is already prefetched, no issue with just using len()
+                    # the queryset is already prefetched, no issue with just using len()
+                    qs_len = len(qs)
                     if qs_len == 0:
                         raise qs.model.DoesNotExist(
                             f"{qs.model._meta.object_name} matching query does not exist."
                         )
                     if qs_len != 1:
                         raise qs.model.MultipleObjectsReturned(
-                            f"get() returned more than one {qs.model._meta.object_name} -- it returned {qs_len}!"
+                            f"get() returned more than one {qs.model._meta.object_name} -- it returned "
+                            f"{qs_len if qs_len < MAX_GET_RESULTS else f'more than {qs_len - 1}'}!"
                         )
                     return qs[0]
                 return qs.get()
diff --git a/strawberry_django/pagination.py b/strawberry_django/pagination.py
index 6d4f7a56..31be9dd2 100644
--- a/strawberry_django/pagination.py
+++ b/strawberry_django/pagination.py
@@ -6,6 +6,7 @@
 from django.db import DEFAULT_DB_ALIAS
 from django.db.models import Count, QuerySet, Window
 from django.db.models.functions import RowNumber
+from django.db.models.query import MAX_GET_RESULTS
 from strawberry.types import Info
 from strawberry.types.arguments import StrawberryArgument
 from strawberry.types.unset import UNSET, UnsetType
@@ -343,6 +344,19 @@ def get_queryset(
         if self.is_paginated:
             return queryset
 
+        # Add implicit pagination if this field is not a list
+        # that way when first() / get() is called on the QuerySet it does not cause extra queries
+        if not pagination and not (
+            self.is_list or self.is_paginated or self.is_connection
+        ):
+            if self.is_optional:
+                # first() applies order by pk if not ordered
+                if not queryset.ordered:
+                    queryset = queryset.order_by("pk")
+                pagination = OffsetPaginationInput(offset=0, limit=1)
+            else:
+                pagination = OffsetPaginationInput(offset=0, limit=MAX_GET_RESULTS)
+
         return self.apply_pagination(
             queryset,
             pagination,

From 8783f5b45ce2e8784f64a1b223b71dfc2f387b96 Mon Sep 17 00:00:00 2001
From: Take Weiland <diesieben07@gmail.com>
Date: Tue, 17 Dec 2024 16:32:44 +0100
Subject: [PATCH 10/12] Fix typos in comment

---
 strawberry_django/fields/field.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/strawberry_django/fields/field.py b/strawberry_django/fields/field.py
index bd70120e..fc5715f7 100644
--- a/strawberry_django/fields/field.py
+++ b/strawberry_django/fields/field.py
@@ -290,7 +290,7 @@ def qs_hook(qs: models.QuerySet):  # type: ignore
             def qs_hook(qs: models.QuerySet):
                 qs = self.get_queryset(qs, info, **kwargs)
                 # Don't use qs.get() if the queryset is optimized by prefetching.
-                # Calling first in that case would disregard the prefetched results, because first implicitly
+                # Calling get in that case would disregard the prefetched results, because get implicitly
                 # adds a limit to the query
                 if is_optimized_by_prefetching(qs):
                     # mimic behavior of get()

From 51a629122977abd0a06c393c68a6b4bbbff86bb0 Mon Sep 17 00:00:00 2001
From: Take Weiland <diesieben07@gmail.com>
Date: Tue, 17 Dec 2024 16:34:37 +0100
Subject: [PATCH 11/12] Add comment about why we add implicit pagination

---
 strawberry_django/pagination.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/strawberry_django/pagination.py b/strawberry_django/pagination.py
index 31be9dd2..631034a2 100644
--- a/strawberry_django/pagination.py
+++ b/strawberry_django/pagination.py
@@ -346,6 +346,7 @@ def get_queryset(
 
         # Add implicit pagination if this field is not a list
         # that way when first() / get() is called on the QuerySet it does not cause extra queries
+        # and we don't prefetch more than necessary
         if not pagination and not (
             self.is_list or self.is_paginated or self.is_connection
         ):

From 913c5f6e32b689476512516d5e0bd88f97e58f5c Mon Sep 17 00:00:00 2001
From: Thiago Bellini Ribeiro <thiago@bellini.dev>
Date: Wed, 18 Dec 2024 19:04:02 +0100
Subject: [PATCH 12/12] refactor: Use qs._result_cache instead of `len()` for
 safety reasons

---
 strawberry_django/fields/field.py                    | 9 +++++----
 strawberry_django/pagination.py                      | 2 +-
 tests/projects/schema.py                             | 4 ++--
 tests/projects/snapshots/schema.gql                  | 4 ++--
 tests/projects/snapshots/schema_with_inheritance.gql | 8 ++++----
 5 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/strawberry_django/fields/field.py b/strawberry_django/fields/field.py
index fc5715f7..f86c35c5 100644
--- a/strawberry_django/fields/field.py
+++ b/strawberry_django/fields/field.py
@@ -31,7 +31,7 @@
     ReverseOneToOneDescriptor,
 )
 from django.db.models.manager import BaseManager
-from django.db.models.query import MAX_GET_RESULTS
+from django.db.models.query import MAX_GET_RESULTS  # type: ignore
 from django.db.models.query_utils import DeferredAttribute
 from strawberry import UNSET, relay
 from strawberry.annotation import StrawberryAnnotation
@@ -292,10 +292,10 @@ def qs_hook(qs: models.QuerySet):
                 # Don't use qs.get() if the queryset is optimized by prefetching.
                 # Calling get in that case would disregard the prefetched results, because get implicitly
                 # adds a limit to the query
-                if is_optimized_by_prefetching(qs):
+                if (result_cache := qs._result_cache) is not None:  # type: ignore
                     # mimic behavior of get()
                     # the queryset is already prefetched, no issue with just using len()
-                    qs_len = len(qs)
+                    qs_len = len(result_cache)
                     if qs_len == 0:
                         raise qs.model.DoesNotExist(
                             f"{qs.model._meta.object_name} matching query does not exist."
@@ -305,7 +305,8 @@ def qs_hook(qs: models.QuerySet):
                             f"get() returned more than one {qs.model._meta.object_name} -- it returned "
                             f"{qs_len if qs_len < MAX_GET_RESULTS else f'more than {qs_len - 1}'}!"
                         )
-                    return qs[0]
+                    return result_cache[0]
+
                 return qs.get()
 
         return qs_hook
diff --git a/strawberry_django/pagination.py b/strawberry_django/pagination.py
index 631034a2..ae62d644 100644
--- a/strawberry_django/pagination.py
+++ b/strawberry_django/pagination.py
@@ -6,7 +6,7 @@
 from django.db import DEFAULT_DB_ALIAS
 from django.db.models import Count, QuerySet, Window
 from django.db.models.functions import RowNumber
-from django.db.models.query import MAX_GET_RESULTS
+from django.db.models.query import MAX_GET_RESULTS  # type: ignore
 from strawberry.types import Info
 from strawberry.types.arguments import StrawberryArgument
 from strawberry.types.unset import UNSET, UnsetType
diff --git a/tests/projects/schema.py b/tests/projects/schema.py
index b44de907..3bc46673 100644
--- a/tests/projects/schema.py
+++ b/tests/projects/schema.py
@@ -159,6 +159,8 @@ class MilestoneType(relay.Node, Named):
         order=IssueOrder,
         pagination=True,
     )
+    first_issue: Optional["IssueType"] = strawberry_django.field(field_name="issues")
+    first_issue_required: "IssueType" = strawberry_django.field(field_name="issues")
     issues_paginated: OffsetPaginated["IssueType"] = strawberry_django.offset_paginated(
         field_name="issues",
         order=IssueOrder,
@@ -169,8 +171,6 @@ class MilestoneType(relay.Node, Named):
             filters=IssueFilter,
         )
     )
-    first_issue: Optional["IssueType"] = strawberry_django.field(field_name="issues")
-    first_issue_required: "IssueType" = strawberry_django.field(field_name="issues")
 
     @strawberry_django.field(
         prefetch_related=[
diff --git a/tests/projects/snapshots/schema.gql b/tests/projects/snapshots/schema.gql
index 61da21ca..eb6f1ad0 100644
--- a/tests/projects/snapshots/schema.gql
+++ b/tests/projects/snapshots/schema.gql
@@ -383,6 +383,8 @@ type MilestoneType implements Node & Named {
   dueDate: Date
   project: ProjectType!
   issues(filters: IssueFilter, order: IssueOrder, pagination: OffsetPaginationInput): [IssueType!]!
+  firstIssue: IssueType
+  firstIssueRequired: IssueType!
   issuesPaginated(pagination: OffsetPaginationInput, order: IssueOrder): IssueTypeOffsetPaginated!
   issuesWithFilters(
     filters: IssueFilter
@@ -399,8 +401,6 @@ type MilestoneType implements Node & Named {
     """Returns the items in the list that come after the specified cursor."""
     last: Int = null
   ): IssueTypeConnection!
-  firstIssue: IssueType
-  firstIssueRequired: IssueType!
   myIssues: [IssueType!]!
   myBugsCount: Int!
   asyncField(value: String!): String!
diff --git a/tests/projects/snapshots/schema_with_inheritance.gql b/tests/projects/snapshots/schema_with_inheritance.gql
index 748c1ffd..b98209fb 100644
--- a/tests/projects/snapshots/schema_with_inheritance.gql
+++ b/tests/projects/snapshots/schema_with_inheritance.gql
@@ -173,6 +173,8 @@ type MilestoneType implements Node & Named {
   dueDate: Date
   project: ProjectType!
   issues(filters: IssueFilter, order: IssueOrder, pagination: OffsetPaginationInput): [IssueType!]!
+  firstIssue: IssueType
+  firstIssueRequired: IssueType!
   issuesPaginated(pagination: OffsetPaginationInput, order: IssueOrder): IssueTypeOffsetPaginated!
   issuesWithFilters(
     filters: IssueFilter
@@ -189,8 +191,6 @@ type MilestoneType implements Node & Named {
     """Returns the items in the list that come after the specified cursor."""
     last: Int = null
   ): IssueTypeConnection!
-  firstIssue: IssueType
-  firstIssueRequired: IssueType!
   myIssues: [IssueType!]!
   myBugsCount: Int!
   asyncField(value: String!): String!
@@ -203,6 +203,8 @@ type MilestoneTypeSubclass implements Node & Named {
   dueDate: Date
   project: ProjectType!
   issues(filters: IssueFilter, order: IssueOrder, pagination: OffsetPaginationInput): [IssueType!]!
+  firstIssue: IssueType
+  firstIssueRequired: IssueType!
   issuesPaginated(pagination: OffsetPaginationInput, order: IssueOrder): IssueTypeOffsetPaginated!
   issuesWithFilters(
     filters: IssueFilter
@@ -219,8 +221,6 @@ type MilestoneTypeSubclass implements Node & Named {
     """Returns the items in the list that come after the specified cursor."""
     last: Int = null
   ): IssueTypeConnection!
-  firstIssue: IssueType
-  firstIssueRequired: IssueType!
   myIssues: [IssueType!]!
   myBugsCount: Int!
   asyncField(value: String!): String!