example/api/src/main.py

@@ -14,6 +14,8 @@ from cpl.core.utils.cache import Cache
 from cpl.database.mysql.mysql_module import MySQLModule
 from cpl.graphql.application.graphql_app import GraphQLApp
 from cpl.graphql.graphql_module import GraphQLModule
+from model.author_dao import AuthorDao
+from model.author_query import AuthorGraphType, AuthorFilter, AuthorSort
 from model.post_dao import PostDao
 from model.post_query import PostFilter, PostSort, PostGraphType
 from queries.hello import HelloQuery
@@ -49,14 +51,18 @@ def main():
         .add_transient(AuthUserFilter)
         .add_transient(AuthUserSort)
         .add_transient(HelloQuery)
+        # test data
+        .add_singleton(TestDataSeeder)
+        # authors
+        .add_transient(AuthorDao)
+        .add_transient(AuthorGraphType)
+        .add_transient(AuthorFilter)
+        .add_transient(AuthorSort)
         # posts
         .add_transient(PostDao)
         .add_transient(PostGraphType)
         .add_transient(PostFilter)
         .add_transient(PostSort)
-
-        # test data
-        .add_singleton(TestDataSeeder)
     )
 
     app = builder.build()
@@ -78,6 +84,7 @@ def main():
     schema = app.with_graphql()
     schema.query.string_field("ping", resolver=lambda: "pong")
     schema.query.with_query("hello", HelloQuery)
+    schema.query.dao_collection_field(AuthorGraphType, AuthorDao, "authors", AuthorFilter, AuthorSort)
     schema.query.dao_collection_field(PostGraphType, PostDao, "posts", PostFilter, PostSort)
 
     app.with_playground()

example/api/src/model/author.py

@@ -0,0 +1,30 @@
+from datetime import datetime
+from typing import Self
+
+from cpl.core.typing import SerialId
+from cpl.database.abc import DbModelABC
+
+
+class Author(DbModelABC[Self]):
+
+    def __init__(
+        self,
+        id: int,
+        first_name: str,
+        last_name: str,
+        deleted: bool = False,
+        editor_id: SerialId | None = None,
+        created: datetime | None = None,
+        updated: datetime | None = None,
+    ):
+        DbModelABC.__init__(self, id, deleted, editor_id, created, updated)
+        self._first_name = first_name
+        self._last_name = last_name
+
+    @property
+    def first_name(self) -> str:
+        return self._first_name
+
+    @property
+    def last_name(self) -> str:
+        return self._last_name

example/api/src/model/author_dao.py

@@ -0,0 +1,11 @@
+from cpl.database.abc import DbModelDaoABC
+from model.author import Author
+
+
+class AuthorDao(DbModelDaoABC):
+
+    def __init__(self):
+        DbModelDaoABC.__init__(self, Author, "authors")
+
+        self.attribute(Author.first_name, str)
+        self.attribute(Author.last_name, str)

example/api/src/model/author_query.py

@@ -0,0 +1,37 @@
+from cpl.graphql.schema.filter.filter import Filter
+from cpl.graphql.schema.graph_type import GraphType
+from cpl.graphql.schema.sort.sort import Sort
+from cpl.graphql.schema.sort.sort_order import SortOrder
+from model.author import Author
+
+class AuthorFilter(Filter[Author]):
+    def __init__(self):
+        Filter.__init__(self)
+        self.int_field("id")
+        self.string_field("firstName")
+        self.string_field("lastName")
+
+class AuthorSort(Sort[Author]):
+    def __init__(self):
+        Sort.__init__(self)
+        self.field("id", SortOrder)
+        self.field("firstName", SortOrder)
+        self.field("lastName", SortOrder)
+
+class AuthorGraphType(GraphType[Author]):
+
+    def __init__(self):
+        GraphType.__init__(self)
+
+        self.int_field(
+            "id",
+            resolver=lambda root: root.id,
+        )
+        self.string_field(
+            "firstName",
+            resolver=lambda root: root.first_name,
+        )
+        self.string_field(
+            "lastName",
+            resolver=lambda root: root.last_name,
+        )

example/api/src/model/post.py

@@ -10,6 +10,7 @@ class Post(DbModelABC[Self]):
     def __init__(
         self,
         id: int,
+        author_id: SerialId,
         title: str,
         content: str,
         deleted: bool = False,
@@ -18,9 +19,14 @@ class Post(DbModelABC[Self]):
         updated: datetime | None = None,
     ):
         DbModelABC.__init__(self, id, deleted, editor_id, created, updated)
+        self._author_id = author_id
         self._title = title
         self._content = content
 
+    @property
+    def author_id(self) -> SerialId:
+        return self._author_id
+
     @property
     def title(self) -> str:
         return self._title

example/api/src/model/post_dao.py

@@ -1,11 +1,15 @@
 from cpl.database.abc import DbModelDaoABC
+from model.author_dao import AuthorDao
 from model.post import Post
 
 
 class PostDao(DbModelDaoABC):
 
-    def __init__(self):
+    def __init__(self, authors: AuthorDao):
         DbModelDaoABC.__init__(self, Post, "posts")
 
+        self.attribute(Post.author_id, int, db_name="authorId")
+        self.reference("author", "id", Post.author_id, "authors", authors)
+
         self.attribute(Post.title, str)
         self.attribute(Post.content, str)

example/api/src/model/post_query.py

@@ -2,12 +2,15 @@ from cpl.graphql.schema.filter.filter import Filter
 from cpl.graphql.schema.graph_type import GraphType
 from cpl.graphql.schema.sort.sort import Sort
 from cpl.graphql.schema.sort.sort_order import SortOrder
+from model.author_dao import AuthorDao
+from model.author_query import AuthorGraphType, AuthorFilter
 from model.post import Post
 
 class PostFilter(Filter[Post]):
     def __init__(self):
         Filter.__init__(self)
         self.int_field("id")
+        self.filter_field("author", AuthorFilter)
         self.string_field("title")
         self.string_field("content")
 
@@ -20,13 +23,22 @@ class PostSort(Sort[Post]):
 
 class PostGraphType(GraphType[Post]):
 
-    def __init__(self):
+    def __init__(self, authors: AuthorDao):
         GraphType.__init__(self)
 
         self.int_field(
             "id",
             resolver=lambda root: root.id,
         )
+
+        async def _a(root: Post):
+            return await authors.get_by_id(root.author_id)
+
+        self.object_field(
+            "author",
+            AuthorGraphType,
+            resolver=_a#lambda root: root.author_id,
+        )
         self.string_field(
             "title",
             resolver=lambda root: root.title,

example/api/src/scripts/0-posts.sql

@@ -1,7 +1,19 @@
-CREATE TABLE IF NOT EXISTS `posts` (
+CREATE TABLE IF NOT EXISTS `authors` (
     `id` INT(30) NOT NULL AUTO_INCREMENT,
-    `title` VARCHAR(64) NOT NULL,
-    `content` VARCHAR(512) NOT NULL,
+    `firstname` VARCHAR(64) NOT NULL,
+    `lastname` VARCHAR(64) NOT NULL,
+    deleted BOOLEAN NOT NULL DEFAULT FALSE,
+    editorId INT NULL,
+    created TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
+    PRIMARY KEY(`id`)
+    );
+
+CREATE TABLE IF NOT EXISTS `posts` (
+    `id` INT(30) NOT NULL AUTO_INCREMENT,
+    `authorId` INT(30) NOT NULL REFERENCES `authors`(`id`) ON DELETE CASCADE,
+    `title` TEXT NOT NULL,
+    `content` TEXT NOT NULL,
     deleted BOOLEAN NOT NULL DEFAULT FALSE,
     editorId INT NULL,
     created TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,

example/api/src/test_data_seeder.py

@@ -2,6 +2,8 @@ from faker import Faker
 
 from cpl.database.abc import DataSeederABC
 from cpl.query import Enumerable
+from model.author import Author
+from model.author_dao import AuthorDao
 from model.post import Post
 from model.post_dao import PostDao
 
@@ -11,19 +13,34 @@ fake = Faker()
 
 class TestDataSeeder(DataSeederABC):
 
-    def __init__(self, posts: PostDao):
+    def __init__(self, authors: AuthorDao, posts: PostDao):
         DataSeederABC.__init__(self)
 
+        self._authors = authors
         self._posts = posts
 
     async def seed(self):
+        if await self._authors.count() == 0:
+            await self._seed_authors()
+
         if await self._posts.count() == 0:
             await self._seed_posts()
 
+    async def _seed_authors(self):
+        authors = Enumerable.range(0, 35).select(
+            lambda x: Author(
+                0,
+                fake.first_name(),
+                fake.last_name(),
+        )
+        ).to_list()
+        await self._authors.create_many(authors, skip_editor=True)
+
     async def _seed_posts(self):
         posts = Enumerable.range(0, 100).select(
             lambda x: Post(
                 id=0,
+                author_id=fake.random_int(min=1, max=35),
                 title=fake.sentence(nb_words=6),
                 content=fake.paragraph(nb_sentences=6),
             )

src/cpl-database/cpl/database/mysql/mysql_pool.py

@@ -1,6 +1,8 @@
 from typing import Optional, Any
-
 import sqlparse
+import asyncio
+
+from mysql.connector import errors, PoolError
 from mysql.connector.aio import MySQLConnectionPool
 
 from cpl.core.environment import Environment
@@ -10,7 +12,6 @@ from cpl.dependency.context import get_provider
 
 
 class MySQLPool:
-
     def __init__(self, database_settings: DatabaseSettings):
         self._dbconfig = {
             "host": database_settings.host,
@@ -25,35 +26,66 @@ class MySQLPool:
             "ssl_disabled": database_settings.ssl_disabled,
         }
         self._pool: Optional[MySQLConnectionPool] = None
+        self._pool_lock = asyncio.Lock()
 
-    async def _get_pool(self):
+    async def _get_pool(self) -> MySQLConnectionPool:
+        if self._pool is None:
+            async with self._pool_lock:
                 if self._pool is None:
                     try:
                         self._pool = MySQLConnectionPool(
-                    pool_name="mypool", pool_size=Environment.get("DB_POOL_SIZE", int, 1), **self._dbconfig
+                            pool_name="cplpool",
+                            pool_size=Environment.get("DB_POOL_SIZE", int, 20),
+                            **self._dbconfig,
                         )
                         await self._pool.initialize_pool()
 
+                        # Testverbindung (Ping)
                         con = await self._pool.get_connection()
+                        try:
                             async with await con.cursor() as cursor:
                                 await cursor.execute("SELECT 1")
                                 await cursor.fetchall()
-
+                        finally:
                             await con.close()
+
                     except Exception as e:
                         logger = get_provider().get_service(DBLogger)
-                logger.fatal(f"Error connecting to the database", e)
-
+                        logger.fatal("Error connecting to the database", e)
+                        raise
         return self._pool
 
+    async def _get_connection(self, retries: int = 3, delay: float = 0.5):
+        """Stabiler Connection-Getter mit Retry und Ping"""
+        pool = await self._get_pool()
+
+        for attempt in range(retries):
+            try:
+                con = await pool.get_connection()
+
+                # Verbindungs-Check (Ping)
+                try:
+                    async with await con.cursor() as cursor:
+                        await cursor.execute("SELECT 1")
+                        await cursor.fetchall()
+                except errors.OperationalError:
+                    await con.close()
+                    raise
+
+                return con
+
+            except PoolError:
+                if attempt == retries - 1:
+                    raise
+                await asyncio.sleep(delay)
+
     @staticmethod
     async def _exec_sql(cursor: Any, query: str, args=None, multi=True):
         result = []
         if multi:
             queries = [str(stmt).strip() for stmt in sqlparse.parse(query) if str(stmt).strip()]
             for q in queries:
-                if q.strip() == "":
-                    continue
+                if q:
                     await cursor.execute(q, args)
                     if cursor.description is not None:
                         result = await cursor.fetchall()
@@ -61,23 +93,20 @@ class MySQLPool:
             await cursor.execute(query, args)
             if cursor.description is not None:
                 result = await cursor.fetchall()
-
         return result
 
-    async def execute(self, query: str, args=None, multi=True) -> list[list]:
-        pool = await self._get_pool()
-        con = await pool.get_connection()
+    async def execute(self, query: str, args=None, multi=True) -> list[str]:
+        con = await self._get_connection()
         try:
             async with await con.cursor() as cursor:
-                result = await self._exec_sql(cursor, query, args, multi)
+                res = await self._exec_sql(cursor, query, args, multi)
                 await con.commit()
-                return result
+                return list(res)
         finally:
             await con.close()
 
     async def select(self, query: str, args=None, multi=True) -> list[str]:
-        pool = await self._get_pool()
-        con = await pool.get_connection()
+        con = await self._get_connection()
         try:
             async with await con.cursor() as cursor:
                 res = await self._exec_sql(cursor, query, args, multi)
@@ -86,8 +115,7 @@ class MySQLPool:
             await con.close()
 
     async def select_map(self, query: str, args=None, multi=True) -> list[dict]:
-        pool = await self._get_pool()
-        con = await pool.get_connection()
+        con = await self._get_connection()
         try:
             async with await con.cursor(dictionary=True) as cursor:
                 res = await self._exec_sql(cursor, query, args, multi)

src/cpl-database/cpl/database/postgres/postgres_pool.py

@@ -27,7 +27,7 @@ class PostgresPool:
         self._pool: Optional[AsyncConnectionPool] = None
 
     async def _get_pool(self):
-        if self._pool is None:
+        if self._pool is None or self._pool.closed:
             pool = AsyncConnectionPool(
                 conninfo=self._conninfo, open=False, min_size=1, max_size=Environment.get("DB_POOL_SIZE", int, 1)
             )

src/cpl-graphql/cpl/graphql/schema/collection.py

@@ -3,6 +3,7 @@ from typing import Type, Dict, List
 import strawberry
 
 from cpl.core.typing import T
+from cpl.dependency import get_provider
 from cpl.graphql.abc.strawberry_protocol import StrawberryProtocol
 
 
@@ -14,7 +15,12 @@ class CollectionGraphTypeFactory:
         if node_type in cls._cache:
             return cls._cache[node_type]
 
-        gql_node = node_type().to_strawberry() if hasattr(node_type, "to_strawberry") else node_type
+        node_t = get_provider().get_service(node_type)
+        if not node_t:
+            raise ValueError(f"Node type '{node_type.__name__}' not registered in service provider")
+
+
+        gql_node = node_t.to_strawberry() if hasattr(node_type, "to_strawberry") else node_type
 
         gql_type = strawberry.type(
             type(

src/cpl-graphql/cpl/graphql/schema/filter/filter.py

@@ -1,3 +1,5 @@
+from typing import Type
+
 from cpl.core.typing import T
 from cpl.graphql.schema.filter.bool_filter import BoolFilter
 from cpl.graphql.schema.filter.date_filter import DateFilter
@@ -10,6 +12,9 @@ class Filter(Input[T]):
     def __init__(self):
         Input.__init__(self)
 
+    def filter_field(self, name: str, filter_type: Type["Filter"]):
+        self.field(name, filter_type())
+
     def string_field(self, name: str):
         self.field(name, StringFilter())
 

src/cpl-graphql/cpl/graphql/schema/input.py

@@ -5,6 +5,7 @@ import strawberry
 from cpl.core.typing import T
 from cpl.graphql.abc.strawberry_protocol import StrawberryProtocol
 from cpl.graphql.schema.field import Field
+from cpl.graphql.utils.type_collector import TypeCollector
 
 _PYTHON_KEYWORDS = {"in", "not", "is", "and", "or"}
 
@@ -18,12 +19,10 @@ class Input(StrawberryProtocol, Generic[T]):
     def field(self, name: str, typ: Union[type, "Input"], optional: bool = True):
         self._fields[name] = Field(name, typ, optional=optional)
 
-    _registry: dict[type, Type] = {}
-
     def to_strawberry(self) -> Type:
         cls = self.__class__
-        if cls in self._registry:
-            return self._registry[cls]
+        if TypeCollector.has(cls):
+            return TypeCollector.get(cls)
 
         annotations = {}
         namespace = {}
@@ -50,5 +49,5 @@ class Input(StrawberryProtocol, Generic[T]):
         namespace["__annotations__"] = annotations
 
         gql_type = strawberry.input(type(f"{cls.__name__}", (), namespace))
-        Input._registry[cls] = gql_type
+        TypeCollector.set(cls, gql_type)
         return gql_type

src/cpl-graphql/cpl/graphql/schema/query.py

@@ -12,6 +12,7 @@ from cpl.graphql.schema.collection import Collection, CollectionGraphTypeFactory
 from cpl.graphql.schema.field import Field
 from cpl.graphql.schema.sort.sort_order import SortOrder
 from cpl.graphql.typing import Resolver
+from cpl.graphql.utils.type_collector import TypeCollector
 
 
 class Query(StrawberryProtocol):
@@ -54,6 +55,9 @@ class Query(StrawberryProtocol):
     def list_field(self, name: str, t: type, resolver: Resolver = None) -> Field:
         return self.field(name, list[t], resolver)
 
+    def object_field(self, name: str, t: Type[StrawberryProtocol], resolver: Resolver = None) -> Field:
+        return self.field(name, t().to_strawberry(), resolver)
+
     def with_query(self, name: str, subquery_cls: Type["Query"]):
         sub = self._provider.get_service(subquery_cls)
         if not sub:
@@ -221,6 +225,10 @@ class Query(StrawberryProtocol):
             ) from e
 
     def to_strawberry(self) -> Type:
+        cls = self.__class__
+        if TypeCollector.has(cls):
+            return TypeCollector.get(cls)
+
         annotations: dict[str, Any] = {}
         namespace: dict[str, Any] = {}
 
@@ -229,4 +237,6 @@ class Query(StrawberryProtocol):
             namespace[name] = self._field_to_strawberry(f)
 
         namespace["__annotations__"] = annotations
-        return strawberry.type(type(f"{self.__class__.__name__.replace("GraphType", "")}", (), namespace))
+        gql_type = strawberry.type(type(f"{self.__class__.__name__.replace("GraphType", "")}", (), namespace))
+        TypeCollector.set(cls, gql_type)
+        return gql_type

src/cpl-graphql/cpl/graphql/utils/type_collector.py

@@ -0,0 +1,17 @@
+from typing import Type
+
+
+class TypeCollector:
+    _registry: dict[type, Type] = {}
+
+    @classmethod
+    def has(cls, base: type) -> bool:
+        return base in cls._registry
+
+    @classmethod
+    def get(cls, base: type) -> Type:
+        return cls._registry[base]
+
+    @classmethod
+    def set(cls, base: type, gql_type: Type):
+        cls._registry[base] = gql_type