From 5d197daaf59362a138b132a619849cdac109dc99 Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Wed, 27 Mar 2024 15:09:10 -0300
Subject: [PATCH 01/34] add psycopg2 dependency

---
 pyproject.toml       | 15 +++++++--------
 requirements/dev.txt |  1 +
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/pyproject.toml b/pyproject.toml
index 1d3e2326..b14321d4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -2,9 +2,11 @@
 name = "Flask-Session"
 description = "Server-side session support for Flask"
 readme = "README.md"
-license = {text = "BSD-3-Clause"}
-maintainers = [{name = "Pallets Community Ecosystem", email = "contact@palletsprojects.com"}]
-authors = [{name = "Shipeng Feng", email = "fsp261@gmail.com"}]
+license = { text = "BSD-3-Clause" }
+maintainers = [
+    { name = "Pallets Community Ecosystem", email = "contact@palletsprojects.com" },
+]
+authors = [{ name = "Shipeng Feng", email = "fsp261@gmail.com" }]
 classifiers = [
     "Development Status :: 4 - Beta",
     "Environment :: Web Environment",
@@ -19,11 +21,7 @@ classifiers = [
     "Topic :: Software Development :: Libraries :: Application Frameworks",
 ]
 requires-python = ">=3.8"
-dependencies = [
-    "flask>=2.2",
-    "msgspec>=0.18.6",
-    "cachelib",
-]
+dependencies = ["flask>=2.2", "msgspec>=0.18.6", "cachelib"]
 dynamic = ["version"]
 
 [project.urls]
@@ -88,4 +86,5 @@ dev-dependencies = [
     "boto3>=1.34.68",
     "mypy_boto3_dynamodb>=1.34.67",
     "pymemcache>=4.0.0",
+    "psycopg2-binary>=2",
 ]
diff --git a/requirements/dev.txt b/requirements/dev.txt
index 14205475..868d1b06 100644
--- a/requirements/dev.txt
+++ b/requirements/dev.txt
@@ -17,4 +17,5 @@ Flask-SQLAlchemy
 pymongo
 boto3
 mypy_boto3_dynamodb
+psycopg2-binary
 

From a56e68cc1d187f0e45a10d9bcadcdb1c323336f1 Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Wed, 27 Mar 2024 15:25:03 -0300
Subject: [PATCH 02/34] setup basic structure

---
 src/flask_session/postgres/__init__.py |  0
 src/flask_session/postgres/postgres.py | 87 ++++++++++++++++++++++++++
 2 files changed, 87 insertions(+)
 create mode 100644 src/flask_session/postgres/__init__.py
 create mode 100644 src/flask_session/postgres/postgres.py

diff --git a/src/flask_session/postgres/__init__.py b/src/flask_session/postgres/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/src/flask_session/postgres/postgres.py b/src/flask_session/postgres/postgres.py
new file mode 100644
index 00000000..c2c38d85
--- /dev/null
+++ b/src/flask_session/postgres/postgres.py
@@ -0,0 +1,87 @@
+from __future__ import annotations
+
+from typing import Optional
+
+from flask import Flask
+from psycopg2.pool import ThreadedConnectionPool
+from datetime import timedelta as TimeDelta
+
+from ..base import ServerSideSession, ServerSideSessionInterface
+from ..defaults import Defaults
+
+DEFAULT_TABLE_NAME = "flask_sessions"
+DEFAULT_SCHEMA_NAME = "public"
+DEFAULT_PG_MAX_DB_CONN = 10
+
+class PostgreSqlSession(ServerSideSession):
+    pass
+
+
+class PostgreSqlSessionInterface(ServerSideSessionInterface):
+    pass
+
+    session_class = PostgreSqlSession
+    ttl = True
+
+
+    def __init__(
+        self,
+        uri: str,
+        *,
+        app: Flask,
+        key_prefix: str = Defaults.SESSION_KEY_PREFIX,
+        use_signer: bool = Defaults.SESSION_USE_SIGNER,
+        permanent: bool = Defaults.SESSION_PERMANENT,
+        sid_length: int = Defaults.SESSION_ID_LENGTH,
+        serialization_format: str = Defaults.SESSION_SERIALIZATION_FORMAT,
+        cleanup_n_requests: Optional[int] = Defaults.SESSION_CLEANUP_N_REQUESTS,
+        table_name: str = DEFAULT_TABLE_NAME,
+        schema_name: str = DEFAULT_SCHEMA_NAME,
+        max_db_conn: int = DEFAULT_PG_MAX_DB_CONN,
+    ) -> None:
+        """Initialize a new Flask-PgSession instance.
+
+        Args:
+            uri (str): The database URI to connect to.
+            table_name (str, optional): The name of the table to store sessions in.
+                Defaults to "flask_sessions".
+            schema_name (str, optional): The name of the schema to store sessions in.
+                Defaults to "public".
+            key_prefix (str, optional): The prefix to prepend to the session ID when
+                storing it in the database. Defaults to "".
+            use_signer (bool, optional): Whether to use a signer to sign the session.
+                Defaults to False.
+            permanent (bool, optional): Whether the session should be permanent.
+                Defaults to True.
+            autodelete_expired_sessions (bool, optional): Whether to automatically
+                delete expired sessions. Defaults to True.
+            max_db_conn (int, optional): The maximum number of database connections to
+                keep open. Defaults to 10.
+        """
+        self.pool = ThreadedConnectionPool(1, max_db_conn, uri)
+
+        self._table = table_name
+        self._schema = schema_name
+
+        super().__init__(
+            app,
+            key_prefix,
+            use_signer,
+            permanent,
+            sid_length,
+            serialization_format,
+            cleanup_n_requests,
+        )
+
+        def _delete_expired_sessions(self) -> None:
+            raise NotImplementedError
+
+        def _delete_session(self, store_id:str) -> None:
+            raise NotImplementedError
+
+        def _upsert_session(self, session_lifetime:TimeDelta, session: ServerSideSession, store_id: str) -> None:
+            raise NotImplementedError
+
+        def _retrieve_session_data(self, store_id: str)-> Optional[dict]:
+            raise NotImplementedError
+

From 6cdc30f6491761487680f2dca392153db9bfa20d Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Wed, 27 Mar 2024 15:26:05 -0300
Subject: [PATCH 03/34] copy queries from flask-pg-sessions repo

---
 src/flask_session/postgres/_queries.py | 78 ++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 src/flask_session/postgres/_queries.py

diff --git a/src/flask_session/postgres/_queries.py b/src/flask_session/postgres/_queries.py
new file mode 100644
index 00000000..ae47aa93
--- /dev/null
+++ b/src/flask_session/postgres/_queries.py
@@ -0,0 +1,78 @@
+from psycopg2 import sql
+
+
+class Queries:
+    def __init__(self, schema: str, table: str) -> None:
+        """Class to hold all the queries used by the session interface.
+
+        Args:
+            schema (str): The name of the schema to use for the session data.
+            table (str): The name of the table to use for the session data.
+        """
+        self.schema = schema
+        self.table = table
+
+    @property
+    def create_schema(self) -> str:
+        return sql.SQL("CREATE SCHEMA IF NOT EXISTS {schema};").format(
+            schema=sql.Identifier(self.schema)
+        )
+
+    @property
+    def create_table(self) -> str:
+        uq_idx = sql.Identifier(f"uq_{self.table}_session_id")
+        expiry_idx = sql.Identifier(f"{self.table}_expiry_idx")
+        return sql.SQL(
+            """CREATE TABLE IF NOT EXISTS {schema}.{table} (
+            session_id VARCHAR(255) NOT NULL PRIMARY KEY,
+            created TIMESTAMP WITHOUT TIME ZONE DEFAULT (NOW() AT TIME ZONE 'utc'),
+            data BYTEA,
+            expiry TIMESTAMP WITHOUT TIME ZONE
+        );
+
+        --- Unique session_id
+        CREATE UNIQUE INDEX IF NOT EXISTS
+            {uq_idx} ON {schema}.{table} (session_id);
+
+        --- Index for expiry timestamp
+        CREATE INDEX IF NOT EXISTS
+            {expiry_idx} ON {schema}.{table} (expiry);"""
+        ).format(
+            schema=sql.Identifier(self.schema),
+            table=sql.Identifier(self.table),
+            uq_idx=uq_idx,
+            expiry_idx=expiry_idx,
+        )
+
+    @property
+    def retrieve_session_data(self) -> str:
+        return sql.SQL(
+            """--- If the current sessions is expired, delete it
+            DELETE FROM {schema}.{table}
+            WHERE session_id = %(session_id)s AND expiry < NOW();
+            --- Else retrieve it
+            SELECT data FROM {schema}.{table} WHERE session_id = %(session_id)s;
+        """
+        ).format(schema=sql.Identifier(self.schema), table=sql.Identifier(self.table))
+
+    @property
+    def upsert_session(self) -> str:
+        return sql.SQL(
+            """INSERT INTO {schema}.{table} (session_id, data, expiry)
+            VALUES (%(session_id)s, %(data)s, %(expiry)s)
+            ON CONFLICT (session_id)
+            DO UPDATE SET data = %(data)s, expiry = %(expiry)s;
+        """
+        ).format(schema=sql.Identifier(self.schema), table=sql.Identifier(self.table))
+
+    @property
+    def delete_expired_sessions(self) -> str:
+        return sql.SQL("DELETE FROM {schema}.{table} WHERE expiry < NOW();").format(
+            schema=sql.Identifier(self.schema), table=sql.Identifier(self.table)
+        )
+
+    @property
+    def delete_session(self) -> str:
+        return sql.SQL(
+            "DELETE FROM {schema}.{table} WHERE session_id = %(session_id)s;"
+        ).format(schema=sql.Identifier(self.schema), table=sql.Identifier(self.table))

From 77046f7217b1c73685c1fbbd8b779c4f3bf81ddb Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Thu, 28 Mar 2024 09:30:36 -0300
Subject: [PATCH 04/34] implement abc methods

---
 src/flask_session/postgres/postgres.py | 93 ++++++++++++++++++++++----
 1 file changed, 81 insertions(+), 12 deletions(-)

diff --git a/src/flask_session/postgres/postgres.py b/src/flask_session/postgres/postgres.py
index c2c38d85..7860bdf8 100644
--- a/src/flask_session/postgres/postgres.py
+++ b/src/flask_session/postgres/postgres.py
@@ -1,18 +1,28 @@
 from __future__ import annotations
 
 from typing import Optional
+from contextlib import contextmanager
 
 from flask import Flask
 from psycopg2.pool import ThreadedConnectionPool
+from psycopg2.extensions import connection as PsycoPg2Connection
+from psycopg2.extensions import cursor as PsycoPg2Cursor
 from datetime import timedelta as TimeDelta
+from datetime import datetime
+from typing import Any, Generator, Optional
+from itsdangerous import want_bytes
 
 from ..base import ServerSideSession, ServerSideSessionInterface
 from ..defaults import Defaults
 
+from ._queries import Queries
+from .._utils import retry_query
+
 DEFAULT_TABLE_NAME = "flask_sessions"
 DEFAULT_SCHEMA_NAME = "public"
 DEFAULT_PG_MAX_DB_CONN = 10
 
+
 class PostgreSqlSession(ServerSideSession):
     pass
 
@@ -23,7 +33,6 @@ class PostgreSqlSessionInterface(ServerSideSessionInterface):
     session_class = PostgreSqlSession
     ttl = True
 
-
     def __init__(
         self,
         uri: str,
@@ -63,6 +72,8 @@ def __init__(
         self._table = table_name
         self._schema = schema_name
 
+        self._queries = Queries(schema=schema_name, table=table_name)
+
         super().__init__(
             app,
             key_prefix,
@@ -73,15 +84,73 @@ def __init__(
             cleanup_n_requests,
         )
 
-        def _delete_expired_sessions(self) -> None:
-            raise NotImplementedError
-
-        def _delete_session(self, store_id:str) -> None:
-            raise NotImplementedError
-
-        def _upsert_session(self, session_lifetime:TimeDelta, session: ServerSideSession, store_id: str) -> None:
-            raise NotImplementedError
-
-        def _retrieve_session_data(self, store_id: str)-> Optional[dict]:
-            raise NotImplementedError
+        # QUERY HELPERS
+
+        @contextmanager
+        def _get_cursor(
+            self, conn: Optional[PsycoPg2Connection] = None
+        ) -> Generator[PsycoPg2Cursor, None, None]:
+            _conn: PsycoPg2Connection = conn or self.pool.getconn()
+
+            assert isinstance(_conn, PsycoPg2Connection)
+            try:
+                with _conn:
+                    with _conn.cursor() as cur:
+                        yield cur
+            except Exception:
+                raise
+            finally:
+                self.pool.putconn(_conn)
+
+        @retry_query(max_attempts=3)
+        def _create_schema_and_table(self) -> None:
+            with self._get_cursor() as cur:
+                cur.execute(self._queries.create_schema)
+                cur.execute(self._queries.create_table)
 
+        def _delete_expired_sessions(self) -> None:
+            """Delete all expired sessions from the database."""
+            with self._get_cursor() as cur:
+                cur.execute(self._queries.delete_expired_sessions)
+
+        @retry_query(max_attempts=3)
+        def _delete_session(self, store_id: str) -> None:
+            with self._get_cursor() as cur:
+                cur.execute(
+                    self._queries.delete_session,
+                    dict(session_id=self._get_store_id(store_id)),
+                )
+
+        @retry_query(max_attempts=3)
+        def _retrieve_session_data(self, store_id: str) -> bytes | None:
+            with self._get_cursor() as cur:
+                cur.execute(
+                    self._queries.retrieve_session_data,
+                    dict(session_id=self._get_store_id(store_id)),
+                )
+                session_data = cur.fetchone()
+
+            if session_data is not None:
+                serialized_session_data = want_bytes(session_data)
+                return self.serializer.decode(serialized_session_data)
+            return None
+
+        @retry_query(max_attempts=3)
+        def _upsert_session(
+            self, session_lifetime: TimeDelta, session: ServerSideSession, store_id: str
+        ) -> None:
+
+            serialized_session_data = self.serializer.encode(session)
+
+            # TODO: use database's NOW() rather than datetime.utcnow()
+            expiry = datetime.utcnow() + session_lifetime
+
+            with self._get_cursor() as cur:
+                cur.execute(
+                    self._queries.upsert_session,
+                    dict(
+                        session_id=session.sid,
+                        data=serialized_session_data,
+                        expiry=expiry,
+                    ),
+                )

From 161b2c954d06c3a27042563e7c013691f6dd6486 Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Thu, 28 Mar 2024 09:32:03 -0300
Subject: [PATCH 05/34] add imports in __init__.py

---
 src/flask_session/postgres/__init__.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/flask_session/postgres/__init__.py b/src/flask_session/postgres/__init__.py
index e69de29b..f78d9a79 100644
--- a/src/flask_session/postgres/__init__.py
+++ b/src/flask_session/postgres/__init__.py
@@ -0,0 +1 @@
+from .postgres import PostgreSqlSession, PostgreSqlSessionInterface  # noqa: F401

From eef255d20c064170085f7b971515fface20af3f5 Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Thu, 28 Mar 2024 09:35:32 -0300
Subject: [PATCH 06/34] pass ttl to upsert query and compute expiry time based
 on database time

---
 src/flask_session/postgres/_queries.py | 6 +++---
 src/flask_session/postgres/postgres.py | 6 +-----
 2 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/src/flask_session/postgres/_queries.py b/src/flask_session/postgres/_queries.py
index ae47aa93..af38a2df 100644
--- a/src/flask_session/postgres/_queries.py
+++ b/src/flask_session/postgres/_queries.py
@@ -58,10 +58,10 @@ def retrieve_session_data(self) -> str:
     @property
     def upsert_session(self) -> str:
         return sql.SQL(
-            """INSERT INTO {schema}.{table} (session_id, data, expiry)
-            VALUES (%(session_id)s, %(data)s, %(expiry)s)
+            """INSERT INTO {schema}.{table} (session_id, data, ttl)
+            VALUES (%(session_id)s, %(data)s, NOW() + %(ttl)s)
             ON CONFLICT (session_id)
-            DO UPDATE SET data = %(data)s, expiry = %(expiry)s;
+            DO UPDATE SET data = %(data)s, expiry = NOW() + %(ttl)s;
         """
         ).format(schema=sql.Identifier(self.schema), table=sql.Identifier(self.table))
 
diff --git a/src/flask_session/postgres/postgres.py b/src/flask_session/postgres/postgres.py
index 7860bdf8..1ae49f33 100644
--- a/src/flask_session/postgres/postgres.py
+++ b/src/flask_session/postgres/postgres.py
@@ -8,7 +8,6 @@
 from psycopg2.extensions import connection as PsycoPg2Connection
 from psycopg2.extensions import cursor as PsycoPg2Cursor
 from datetime import timedelta as TimeDelta
-from datetime import datetime
 from typing import Any, Generator, Optional
 from itsdangerous import want_bytes
 
@@ -142,15 +141,12 @@ def _upsert_session(
 
             serialized_session_data = self.serializer.encode(session)
 
-            # TODO: use database's NOW() rather than datetime.utcnow()
-            expiry = datetime.utcnow() + session_lifetime
-
             with self._get_cursor() as cur:
                 cur.execute(
                     self._queries.upsert_session,
                     dict(
                         session_id=session.sid,
                         data=serialized_session_data,
-                        expiry=expiry,
+                        ttl=session_lifetime,
                     ),
                 )

From 4441ca6e8c45622be8b362892e9d0d8d3ef4d347 Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Thu, 28 Mar 2024 09:35:49 -0300
Subject: [PATCH 07/34] sort imports

---
 src/flask_session/postgres/postgres.py | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/src/flask_session/postgres/postgres.py b/src/flask_session/postgres/postgres.py
index 1ae49f33..f65af349 100644
--- a/src/flask_session/postgres/postgres.py
+++ b/src/flask_session/postgres/postgres.py
@@ -1,21 +1,19 @@
 from __future__ import annotations
 
-from typing import Optional
 from contextlib import contextmanager
+from datetime import timedelta as TimeDelta
+from typing import Any, Generator, Optional
 
 from flask import Flask
-from psycopg2.pool import ThreadedConnectionPool
+from itsdangerous import want_bytes
 from psycopg2.extensions import connection as PsycoPg2Connection
 from psycopg2.extensions import cursor as PsycoPg2Cursor
-from datetime import timedelta as TimeDelta
-from typing import Any, Generator, Optional
-from itsdangerous import want_bytes
+from psycopg2.pool import ThreadedConnectionPool
 
+from .._utils import retry_query
 from ..base import ServerSideSession, ServerSideSessionInterface
 from ..defaults import Defaults
-
 from ._queries import Queries
-from .._utils import retry_query
 
 DEFAULT_TABLE_NAME = "flask_sessions"
 DEFAULT_SCHEMA_NAME = "public"

From a3a4e7b53ca08740bfd4403c4811e53c2db39d92 Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Thu, 28 Mar 2024 09:38:55 -0300
Subject: [PATCH 08/34] linting fixes

---
 src/flask_session/postgres/postgres.py | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/src/flask_session/postgres/postgres.py b/src/flask_session/postgres/postgres.py
index f65af349..630579cc 100644
--- a/src/flask_session/postgres/postgres.py
+++ b/src/flask_session/postgres/postgres.py
@@ -2,7 +2,7 @@
 
 from contextlib import contextmanager
 from datetime import timedelta as TimeDelta
-from typing import Any, Generator, Optional
+from typing import Generator
 
 from flask import Flask
 from itsdangerous import want_bytes
@@ -40,7 +40,7 @@ def __init__(
         permanent: bool = Defaults.SESSION_PERMANENT,
         sid_length: int = Defaults.SESSION_ID_LENGTH,
         serialization_format: str = Defaults.SESSION_SERIALIZATION_FORMAT,
-        cleanup_n_requests: Optional[int] = Defaults.SESSION_CLEANUP_N_REQUESTS,
+        cleanup_n_requests: int | None = Defaults.SESSION_CLEANUP_N_REQUESTS,
         table_name: str = DEFAULT_TABLE_NAME,
         schema_name: str = DEFAULT_SCHEMA_NAME,
         max_db_conn: int = DEFAULT_PG_MAX_DB_CONN,
@@ -85,15 +85,14 @@ def __init__(
 
         @contextmanager
         def _get_cursor(
-            self, conn: Optional[PsycoPg2Connection] = None
+            self, conn: PsycoPg2Connection | None = None
         ) -> Generator[PsycoPg2Cursor, None, None]:
             _conn: PsycoPg2Connection = conn or self.pool.getconn()
 
             assert isinstance(_conn, PsycoPg2Connection)
             try:
-                with _conn:
-                    with _conn.cursor() as cur:
-                        yield cur
+                with _conn, _conn.cursor() as cur:
+                    yield cur
             except Exception:
                 raise
             finally:
@@ -119,7 +118,7 @@ def _delete_session(self, store_id: str) -> None:
                 )
 
         @retry_query(max_attempts=3)
-        def _retrieve_session_data(self, store_id: str) -> bytes | None:
+        def _retrieve_session_data(self, store_id: str) -> dict | None:
             with self._get_cursor() as cur:
                 cur.execute(
                     self._queries.retrieve_session_data,

From 58b445adab348269ffa361c7c2dd37f178131672 Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Thu, 28 Mar 2024 09:41:51 -0300
Subject: [PATCH 09/34] move defaults to dedicated module

---
 src/flask_session/defaults.py          |  5 +++++
 src/flask_session/postgres/postgres.py | 10 +++-------
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/src/flask_session/defaults.py b/src/flask_session/defaults.py
index 7f890d6e..4a341eb0 100644
--- a/src/flask_session/defaults.py
+++ b/src/flask_session/defaults.py
@@ -43,3 +43,8 @@ class Defaults:
     # DynamoDB settings
     SESSION_DYNAMODB = None
     SESSION_DYNAMODB_TABLE = "Sessions"
+
+    # PostgreSQL settings
+    SESSION_POSTGRESQL_TABLE = "flask_sessions"
+    SESSION_POSTGRESQL_SCHEMA = "public"
+    SESSION_POSTGRESQL_MAX_DB_CONN = 10
diff --git a/src/flask_session/postgres/postgres.py b/src/flask_session/postgres/postgres.py
index 630579cc..a46670c7 100644
--- a/src/flask_session/postgres/postgres.py
+++ b/src/flask_session/postgres/postgres.py
@@ -15,10 +15,6 @@
 from ..defaults import Defaults
 from ._queries import Queries
 
-DEFAULT_TABLE_NAME = "flask_sessions"
-DEFAULT_SCHEMA_NAME = "public"
-DEFAULT_PG_MAX_DB_CONN = 10
-
 
 class PostgreSqlSession(ServerSideSession):
     pass
@@ -41,9 +37,9 @@ def __init__(
         sid_length: int = Defaults.SESSION_ID_LENGTH,
         serialization_format: str = Defaults.SESSION_SERIALIZATION_FORMAT,
         cleanup_n_requests: int | None = Defaults.SESSION_CLEANUP_N_REQUESTS,
-        table_name: str = DEFAULT_TABLE_NAME,
-        schema_name: str = DEFAULT_SCHEMA_NAME,
-        max_db_conn: int = DEFAULT_PG_MAX_DB_CONN,
+        table_name: str = Defaults.SESSION_POSTGRESQL_TABLE,
+        schema_name: str = Defaults.SESSION_POSTGRESQL_SCHEMA,
+        max_db_conn: int = Defaults.SESSION_POSTGRESQL_MAX_DB_CONN,
     ) -> None:
         """Initialize a new Flask-PgSession instance.
 

From a9e65e37dbfce3f938b7a246183f9debbaff8f64 Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Thu, 28 Mar 2024 09:42:29 -0300
Subject: [PATCH 10/34] tidy up

---
 src/flask_session/postgres/postgres.py | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/src/flask_session/postgres/postgres.py b/src/flask_session/postgres/postgres.py
index a46670c7..d9ad9c81 100644
--- a/src/flask_session/postgres/postgres.py
+++ b/src/flask_session/postgres/postgres.py
@@ -37,8 +37,8 @@ def __init__(
         sid_length: int = Defaults.SESSION_ID_LENGTH,
         serialization_format: str = Defaults.SESSION_SERIALIZATION_FORMAT,
         cleanup_n_requests: int | None = Defaults.SESSION_CLEANUP_N_REQUESTS,
-        table_name: str = Defaults.SESSION_POSTGRESQL_TABLE,
-        schema_name: str = Defaults.SESSION_POSTGRESQL_SCHEMA,
+        table: str = Defaults.SESSION_POSTGRESQL_TABLE,
+        schema: str = Defaults.SESSION_POSTGRESQL_SCHEMA,
         max_db_conn: int = Defaults.SESSION_POSTGRESQL_MAX_DB_CONN,
     ) -> None:
         """Initialize a new Flask-PgSession instance.
@@ -62,10 +62,10 @@ def __init__(
         """
         self.pool = ThreadedConnectionPool(1, max_db_conn, uri)
 
-        self._table = table_name
-        self._schema = schema_name
+        self._table = table
+        self._schema = schema
 
-        self._queries = Queries(schema=schema_name, table=table_name)
+        self._queries = Queries(schema=self._schema, table=self._table)
 
         super().__init__(
             app,
@@ -77,8 +77,6 @@ def __init__(
             cleanup_n_requests,
         )
 
-        # QUERY HELPERS
-
         @contextmanager
         def _get_cursor(
             self, conn: PsycoPg2Connection | None = None

From 3c3dbff6c9bca3765b023aa71040b42e2f101c38 Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Thu, 28 Mar 2024 09:44:34 -0300
Subject: [PATCH 11/34] fix indentation

---
 src/flask_session/postgres/postgres.py | 128 ++++++++++++-------------
 1 file changed, 64 insertions(+), 64 deletions(-)

diff --git a/src/flask_session/postgres/postgres.py b/src/flask_session/postgres/postgres.py
index d9ad9c81..e5817a74 100644
--- a/src/flask_session/postgres/postgres.py
+++ b/src/flask_session/postgres/postgres.py
@@ -77,67 +77,67 @@ def __init__(
             cleanup_n_requests,
         )
 
-        @contextmanager
-        def _get_cursor(
-            self, conn: PsycoPg2Connection | None = None
-        ) -> Generator[PsycoPg2Cursor, None, None]:
-            _conn: PsycoPg2Connection = conn or self.pool.getconn()
-
-            assert isinstance(_conn, PsycoPg2Connection)
-            try:
-                with _conn, _conn.cursor() as cur:
-                    yield cur
-            except Exception:
-                raise
-            finally:
-                self.pool.putconn(_conn)
-
-        @retry_query(max_attempts=3)
-        def _create_schema_and_table(self) -> None:
-            with self._get_cursor() as cur:
-                cur.execute(self._queries.create_schema)
-                cur.execute(self._queries.create_table)
-
-        def _delete_expired_sessions(self) -> None:
-            """Delete all expired sessions from the database."""
-            with self._get_cursor() as cur:
-                cur.execute(self._queries.delete_expired_sessions)
-
-        @retry_query(max_attempts=3)
-        def _delete_session(self, store_id: str) -> None:
-            with self._get_cursor() as cur:
-                cur.execute(
-                    self._queries.delete_session,
-                    dict(session_id=self._get_store_id(store_id)),
-                )
-
-        @retry_query(max_attempts=3)
-        def _retrieve_session_data(self, store_id: str) -> dict | None:
-            with self._get_cursor() as cur:
-                cur.execute(
-                    self._queries.retrieve_session_data,
-                    dict(session_id=self._get_store_id(store_id)),
-                )
-                session_data = cur.fetchone()
-
-            if session_data is not None:
-                serialized_session_data = want_bytes(session_data)
-                return self.serializer.decode(serialized_session_data)
-            return None
-
-        @retry_query(max_attempts=3)
-        def _upsert_session(
-            self, session_lifetime: TimeDelta, session: ServerSideSession, store_id: str
-        ) -> None:
-
-            serialized_session_data = self.serializer.encode(session)
-
-            with self._get_cursor() as cur:
-                cur.execute(
-                    self._queries.upsert_session,
-                    dict(
-                        session_id=session.sid,
-                        data=serialized_session_data,
-                        ttl=session_lifetime,
-                    ),
-                )
+    @contextmanager
+    def _get_cursor(
+        self, conn: PsycoPg2Connection | None = None
+    ) -> Generator[PsycoPg2Cursor, None, None]:
+        _conn: PsycoPg2Connection = conn or self.pool.getconn()
+
+        assert isinstance(_conn, PsycoPg2Connection)
+        try:
+            with _conn, _conn.cursor() as cur:
+                yield cur
+        except Exception:
+            raise
+        finally:
+            self.pool.putconn(_conn)
+
+    @retry_query(max_attempts=3)
+    def _create_schema_and_table(self) -> None:
+        with self._get_cursor() as cur:
+            cur.execute(self._queries.create_schema)
+            cur.execute(self._queries.create_table)
+
+    def _delete_expired_sessions(self) -> None:
+        """Delete all expired sessions from the database."""
+        with self._get_cursor() as cur:
+            cur.execute(self._queries.delete_expired_sessions)
+
+    @retry_query(max_attempts=3)
+    def _delete_session(self, store_id: str) -> None:
+        with self._get_cursor() as cur:
+            cur.execute(
+                self._queries.delete_session,
+                dict(session_id=self._get_store_id(store_id)),
+            )
+
+    @retry_query(max_attempts=3)
+    def _retrieve_session_data(self, store_id: str) -> dict | None:
+        with self._get_cursor() as cur:
+            cur.execute(
+                self._queries.retrieve_session_data,
+                dict(session_id=self._get_store_id(store_id)),
+            )
+            session_data = cur.fetchone()
+
+        if session_data is not None:
+            serialized_session_data = want_bytes(session_data)
+            return self.serializer.decode(serialized_session_data)
+        return None
+
+    @retry_query(max_attempts=3)
+    def _upsert_session(
+        self, session_lifetime: TimeDelta, session: ServerSideSession, store_id: str
+    ) -> None:
+
+        serialized_session_data = self.serializer.encode(session)
+
+        with self._get_cursor() as cur:
+            cur.execute(
+                self._queries.upsert_session,
+                dict(
+                    session_id=session.sid,
+                    data=serialized_session_data,
+                    ttl=session_lifetime,
+                ),
+            )

From e79befe213948a97cf9ec99da5bc6b1d86a04232 Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Thu, 28 Mar 2024 09:45:10 -0300
Subject: [PATCH 12/34] create schema and table if they don't exist

---
 src/flask_session/postgres/postgres.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/flask_session/postgres/postgres.py b/src/flask_session/postgres/postgres.py
index e5817a74..1748fe1a 100644
--- a/src/flask_session/postgres/postgres.py
+++ b/src/flask_session/postgres/postgres.py
@@ -67,6 +67,8 @@ def __init__(
 
         self._queries = Queries(schema=self._schema, table=self._table)
 
+        self._create_schema_and_table()
+
         super().__init__(
             app,
             key_prefix,

From 6d0ece68a473f5f56be23f178cc5d6b9ba633551 Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Thu, 28 Mar 2024 09:47:05 -0300
Subject: [PATCH 13/34] use store_id arg in upsert_session

---
 src/flask_session/postgres/postgres.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/flask_session/postgres/postgres.py b/src/flask_session/postgres/postgres.py
index 1748fe1a..06b6bddc 100644
--- a/src/flask_session/postgres/postgres.py
+++ b/src/flask_session/postgres/postgres.py
@@ -134,11 +134,14 @@ def _upsert_session(
 
         serialized_session_data = self.serializer.encode(session)
 
+        if session.sid is not None:
+            assert session.sid == store_id
+
         with self._get_cursor() as cur:
             cur.execute(
                 self._queries.upsert_session,
                 dict(
-                    session_id=session.sid,
+                    session_id=store_id,
                     data=serialized_session_data,
                     ttl=session_lifetime,
                 ),

From ae93eaf5221a458d25febfe971003128fd8e0fb4 Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Thu, 28 Mar 2024 12:20:51 -0300
Subject: [PATCH 14/34] fix: misunderstood ttl flag

---
 src/flask_session/postgres/postgres.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/flask_session/postgres/postgres.py b/src/flask_session/postgres/postgres.py
index 06b6bddc..02d3a891 100644
--- a/src/flask_session/postgres/postgres.py
+++ b/src/flask_session/postgres/postgres.py
@@ -24,7 +24,7 @@ class PostgreSqlSessionInterface(ServerSideSessionInterface):
     pass
 
     session_class = PostgreSqlSession
-    ttl = True
+    ttl = False
 
     def __init__(
         self,

From 24d3732254043991c3f94f23d4dd07fe25e1e0ee Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Wed, 3 Apr 2024 09:36:53 -0300
Subject: [PATCH 15/34] pass threadedconnectionpool to constructor rather than
 connection parameters

---
 src/flask_session/defaults.py          | 1 -
 src/flask_session/postgres/postgres.py | 9 +++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/flask_session/defaults.py b/src/flask_session/defaults.py
index 4a341eb0..eab71c70 100644
--- a/src/flask_session/defaults.py
+++ b/src/flask_session/defaults.py
@@ -47,4 +47,3 @@ class Defaults:
     # PostgreSQL settings
     SESSION_POSTGRESQL_TABLE = "flask_sessions"
     SESSION_POSTGRESQL_SCHEMA = "public"
-    SESSION_POSTGRESQL_MAX_DB_CONN = 10
diff --git a/src/flask_session/postgres/postgres.py b/src/flask_session/postgres/postgres.py
index 02d3a891..137482b2 100644
--- a/src/flask_session/postgres/postgres.py
+++ b/src/flask_session/postgres/postgres.py
@@ -28,9 +28,8 @@ class PostgreSqlSessionInterface(ServerSideSessionInterface):
 
     def __init__(
         self,
-        uri: str,
-        *,
         app: Flask,
+        pool: ThreadedConnectionPool,
         key_prefix: str = Defaults.SESSION_KEY_PREFIX,
         use_signer: bool = Defaults.SESSION_USE_SIGNER,
         permanent: bool = Defaults.SESSION_PERMANENT,
@@ -39,7 +38,6 @@ def __init__(
         cleanup_n_requests: int | None = Defaults.SESSION_CLEANUP_N_REQUESTS,
         table: str = Defaults.SESSION_POSTGRESQL_TABLE,
         schema: str = Defaults.SESSION_POSTGRESQL_SCHEMA,
-        max_db_conn: int = Defaults.SESSION_POSTGRESQL_MAX_DB_CONN,
     ) -> None:
         """Initialize a new Flask-PgSession instance.
 
@@ -60,7 +58,10 @@ def __init__(
             max_db_conn (int, optional): The maximum number of database connections to
                 keep open. Defaults to 10.
         """
-        self.pool = ThreadedConnectionPool(1, max_db_conn, uri)
+        if not isinstance(pool, ThreadedConnectionPool):
+            raise TypeError("No valid ThreadedConnectionPool instance provided.")
+
+        self.pool = pool
 
         self._table = table
         self._schema = schema

From bc3ee172caf13a1f1e25b5370c708f4f6863e479 Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Wed, 3 Apr 2024 09:37:27 -0300
Subject: [PATCH 16/34] Remove leftover 'pass'

---
 src/flask_session/postgres/postgres.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/flask_session/postgres/postgres.py b/src/flask_session/postgres/postgres.py
index 137482b2..6391d871 100644
--- a/src/flask_session/postgres/postgres.py
+++ b/src/flask_session/postgres/postgres.py
@@ -21,7 +21,6 @@ class PostgreSqlSession(ServerSideSession):
 
 
 class PostgreSqlSessionInterface(ServerSideSessionInterface):
-    pass
 
     session_class = PostgreSqlSession
     ttl = False

From 1ede44801e2762d5b72dd555223eca32367f68e7 Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Wed, 3 Apr 2024 09:41:46 -0300
Subject: [PATCH 17/34] docstring

---
 src/flask_session/postgres/postgres.py | 33 ++++++++++----------------
 1 file changed, 13 insertions(+), 20 deletions(-)

diff --git a/src/flask_session/postgres/postgres.py b/src/flask_session/postgres/postgres.py
index 6391d871..30133f20 100644
--- a/src/flask_session/postgres/postgres.py
+++ b/src/flask_session/postgres/postgres.py
@@ -21,6 +21,18 @@ class PostgreSqlSession(ServerSideSession):
 
 
 class PostgreSqlSessionInterface(ServerSideSessionInterface):
+    """A Session interface that uses PostgreSQL as a session storage. (`psycopg2` required)
+
+    :param pool: A ``psycopg2.pool.ThreadedConnectionPool`` instance.
+    :param key_prefix: A prefix that is added to all storage keys.
+    :param use_signer: Whether to sign the session id cookie or not.
+    :param permanent: Whether to use permanent session or not.
+    :param sid_length: The length of the generated session id in bytes.
+    :param serialization_format: The serialization format to use for the session data.
+    :param table: The table name you want to use.
+    :param schema: The db schema to use.
+    :param cleanup_n_requests: Delete expired sessions on average every N requests.
+    """
 
     session_class = PostgreSqlSession
     ttl = False
@@ -34,29 +46,10 @@ def __init__(
         permanent: bool = Defaults.SESSION_PERMANENT,
         sid_length: int = Defaults.SESSION_ID_LENGTH,
         serialization_format: str = Defaults.SESSION_SERIALIZATION_FORMAT,
-        cleanup_n_requests: int | None = Defaults.SESSION_CLEANUP_N_REQUESTS,
         table: str = Defaults.SESSION_POSTGRESQL_TABLE,
         schema: str = Defaults.SESSION_POSTGRESQL_SCHEMA,
+        cleanup_n_requests: int | None = Defaults.SESSION_CLEANUP_N_REQUESTS,
     ) -> None:
-        """Initialize a new Flask-PgSession instance.
-
-        Args:
-            uri (str): The database URI to connect to.
-            table_name (str, optional): The name of the table to store sessions in.
-                Defaults to "flask_sessions".
-            schema_name (str, optional): The name of the schema to store sessions in.
-                Defaults to "public".
-            key_prefix (str, optional): The prefix to prepend to the session ID when
-                storing it in the database. Defaults to "".
-            use_signer (bool, optional): Whether to use a signer to sign the session.
-                Defaults to False.
-            permanent (bool, optional): Whether the session should be permanent.
-                Defaults to True.
-            autodelete_expired_sessions (bool, optional): Whether to automatically
-                delete expired sessions. Defaults to True.
-            max_db_conn (int, optional): The maximum number of database connections to
-                keep open. Defaults to 10.
-        """
         if not isinstance(pool, ThreadedConnectionPool):
             raise TypeError("No valid ThreadedConnectionPool instance provided.")
 

From b21760e3b27f1cdc36783918c96eda0601a8537f Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Wed, 3 Apr 2024 09:43:16 -0300
Subject: [PATCH 18/34] add postgres session to api docs

---
 docs/api.rst | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/docs/api.rst b/docs/api.rst
index b31eceb5..31e1e2b1 100644
--- a/docs/api.rst
+++ b/docs/api.rst
@@ -20,4 +20,5 @@ Anything documented here is part of the public API that Flask-Session provides,
 .. autoclass:: flask_session.cachelib.CacheLibSessionInterface
 .. autoclass:: flask_session.mongodb.MongoDBSessionInterface
 .. autoclass:: flask_session.sqlalchemy.SqlAlchemySessionInterface
-.. autoclass:: flask_session.dynamodb.DynamoDBSessionInterface
\ No newline at end of file
+.. autoclass:: flask_session.dynamodb.DynamoDBSessionInterface
+.. autoclass:: flask_session.postgres.PostgreSqlSessionInterface
\ No newline at end of file

From b8ece7faf03d412a72e044ecfc9fdea79780382e Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Wed, 3 Apr 2024 10:08:25 -0300
Subject: [PATCH 19/34] initialisation of postrges session from flask config

---
 src/flask_session/__init__.py          | 30 +++++++++++++++++++++++---
 src/flask_session/defaults.py          |  1 +
 src/flask_session/postgres/postgres.py |  2 +-
 3 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/src/flask_session/__init__.py b/src/flask_session/__init__.py
index b95a0b05..25dff6ba 100644
--- a/src/flask_session/__init__.py
+++ b/src/flask_session/__init__.py
@@ -100,9 +100,6 @@ def _get_interface(self, app):
         SESSION_SQLALCHEMY_BIND_KEY = config.get(
             "SESSION_SQLALCHEMY_BIND_KEY", Defaults.SESSION_SQLALCHEMY_BIND_KEY
         )
-        SESSION_CLEANUP_N_REQUESTS = config.get(
-            "SESSION_CLEANUP_N_REQUESTS", Defaults.SESSION_CLEANUP_N_REQUESTS
-        )
 
         # DynamoDB settings
         SESSION_DYNAMODB = config.get("SESSION_DYNAMODB", Defaults.SESSION_DYNAMODB)
@@ -110,6 +107,22 @@ def _get_interface(self, app):
             "SESSION_DYNAMODB_TABLE", Defaults.SESSION_DYNAMODB_TABLE
         )
 
+        # PostgreSQL settings
+        SESSION_POSTGRESQL = config.get(
+            "SESSION_POSTGRESQL", Defaults.SESSION_POSTGRESQL
+        )
+        SESSION_POSTGRESQL_TABLE = config.get(
+            "SESSION_POSTGRESQL_TABLE", Defaults.SESSION_POSTGRESQL_TABLE
+        )
+        SESSION_POSTGRESQL_SCHEMA = config.get(
+            "SESSION_POSTGRESQL_SCHEMA", Defaults.SESSION_POSTGRESQL_SCHEMA
+        )
+
+        # Shared settings
+        SESSION_CLEANUP_N_REQUESTS = config.get(
+            "SESSION_CLEANUP_N_REQUESTS", Defaults.SESSION_CLEANUP_N_REQUESTS
+        )
+
         common_params = {
             "app": app,
             "key_prefix": SESSION_KEY_PREFIX,
@@ -180,6 +193,17 @@ def _get_interface(self, app):
                 table_name=SESSION_DYNAMODB_TABLE,
             )
 
+        elif SESSION_TYPE == "postgresql":
+            from .postgres import PostgreSqlSessionInterface
+
+            session_interface = PostgreSqlSessionInterface(
+                **common_params,
+                pool=SESSION_POSTGRESQL,
+                table=SESSION_POSTGRESQL_TABLE,
+                schema=SESSION_POSTGRESQL_SCHEMA,
+                cleanup_n_requests=SESSION_CLEANUP_N_REQUESTS,
+            )
+
         else:
             raise ValueError(f"Unrecognized value for SESSION_TYPE: {SESSION_TYPE}")
 
diff --git a/src/flask_session/defaults.py b/src/flask_session/defaults.py
index eab71c70..0467db46 100644
--- a/src/flask_session/defaults.py
+++ b/src/flask_session/defaults.py
@@ -45,5 +45,6 @@ class Defaults:
     SESSION_DYNAMODB_TABLE = "Sessions"
 
     # PostgreSQL settings
+    SESSION_POSTGRESQL = None
     SESSION_POSTGRESQL_TABLE = "flask_sessions"
     SESSION_POSTGRESQL_SCHEMA = "public"
diff --git a/src/flask_session/postgres/postgres.py b/src/flask_session/postgres/postgres.py
index 30133f20..3ebbbbcb 100644
--- a/src/flask_session/postgres/postgres.py
+++ b/src/flask_session/postgres/postgres.py
@@ -40,7 +40,7 @@ class PostgreSqlSessionInterface(ServerSideSessionInterface):
     def __init__(
         self,
         app: Flask,
-        pool: ThreadedConnectionPool,
+        pool: ThreadedConnectionPool | None = Defaults.SESSION_POSTGRESQL,
         key_prefix: str = Defaults.SESSION_KEY_PREFIX,
         use_signer: bool = Defaults.SESSION_USE_SIGNER,
         permanent: bool = Defaults.SESSION_PERMANENT,

From 4b19f7fd0f568f13c5b6eb70c772ebc128bd81b6 Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Wed, 3 Apr 2024 10:15:33 -0300
Subject: [PATCH 20/34] update docs requirements

---
 requirements/docs.in  | 3 ++-
 requirements/docs.txt | 6 ++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/requirements/docs.in b/requirements/docs.in
index 211cd708..b8088dd3 100644
--- a/requirements/docs.in
+++ b/requirements/docs.in
@@ -9,4 +9,5 @@ pymongo
 flask_sqlalchemy
 pymemcache
 boto3
-mypy_boto3_dynamodb
\ No newline at end of file
+mypy_boto3_dynamodb
+psycopg2-binary
\ No newline at end of file
diff --git a/requirements/docs.txt b/requirements/docs.txt
index 81adad9c..0d61012b 100644
--- a/requirements/docs.txt
+++ b/requirements/docs.txt
@@ -6,6 +6,8 @@
 #
 alabaster==0.7.13
     # via sphinx
+async-timeout==4.0.3
+    # via redis
 babel==2.12.1
     # via sphinx
 beautifulsoup4==4.12.3
@@ -36,6 +38,8 @@ flask-sqlalchemy==3.1.1
     # via -r requirements/docs.in
 furo==2024.1.29
     # via -r requirements/docs.in
+greenlet==3.0.3
+    # via sqlalchemy
 idna==3.4
     # via requests
 imagesize==1.4.1
@@ -58,6 +62,8 @@ mypy-boto3-dynamodb==1.34.67
     # via -r requirements/docs.in
 packaging==23.1
     # via sphinx
+psycopg2-binary==2.9.9
+    # via -r requirements/docs.in
 pygments==2.15.1
     # via
     #   furo

From d8ec548083fe5392ebfb11b488e391d9602e5551 Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Wed, 3 Apr 2024 10:49:37 -0300
Subject: [PATCH 21/34] query for dropping sessions table - useful for tests

---
 src/flask_session/postgres/_queries.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/flask_session/postgres/_queries.py b/src/flask_session/postgres/_queries.py
index af38a2df..26745764 100644
--- a/src/flask_session/postgres/_queries.py
+++ b/src/flask_session/postgres/_queries.py
@@ -76,3 +76,9 @@ def delete_session(self) -> str:
         return sql.SQL(
             "DELETE FROM {schema}.{table} WHERE session_id = %(session_id)s;"
         ).format(schema=sql.Identifier(self.schema), table=sql.Identifier(self.table))
+
+    @property
+    def drop_sessions_table(self) -> None:
+        sql.SQL("DROP TABLE IF EXISTS {schema}.{table};").format(
+            schema=sql.Identifier(self.schema), table=sql.Identifier(self.table)
+        )

From 86b5b9c015ecaf9f5ff69fa2607847e13d20976f Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Wed, 3 Apr 2024 12:12:40 -0300
Subject: [PATCH 22/34] add postgres to docker compose

---
 docker-compose.yml | 71 ++++++++++++++++++++++++++--------------------
 1 file changed, 41 insertions(+), 30 deletions(-)

diff --git a/docker-compose.yml b/docker-compose.yml
index 7864e9d7..543ec039 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -1,37 +1,48 @@
-version: '3.8'
+version: "3.8"
 
 services:
-  dynamodb-local:
-    image: "amazon/dynamodb-local:latest"
-    container_name: dynamodb-local
-    ports:
-      - "8000:8000"
-    environment:
-      - AWS_ACCESS_KEY_ID=dummy
-      - AWS_SECRET_ACCESS_KEY=dummy
-      - AWS_DEFAULT_REGION=us-west-2
+    dynamodb-local:
+        image: "amazon/dynamodb-local:latest"
+        container_name: dynamodb-local
+        ports:
+            - "8000:8000"
+        environment:
+            - AWS_ACCESS_KEY_ID=dummy
+            - AWS_SECRET_ACCESS_KEY=dummy
+            - AWS_DEFAULT_REGION=us-west-2
 
-  mongo:
-    image: mongo:latest
-    ports:
-      - "27017:27017"
-    volumes:
-      - mongo_data:/data/db
+    mongo:
+        image: mongo:latest
+        ports:
+            - "27017:27017"
+        volumes:
+            - mongo_data:/data/db
 
-  redis:
-    image: redis:latest
-    ports:
-      - "6379:6379"
-    volumes:
-      - redis_data:/data
+    redis:
+        image: redis:latest
+        ports:
+            - "6379:6379"
+        volumes:
+            - redis_data:/data
 
-  memcached:
-    image: memcached:latest
-    ports:
-      - "11211:11211"
+    memcached:
+        image: memcached:latest
+        ports:
+            - "11211:11211"
+
+    postgres:
+        image: postgres:latest
+        environment:
+            - POSTGRES_USER=root
+            - POSTGRES_PASSWORD=pwd
+            - POSTGRES_DB=dummy
+        ports:
+            - "5433:5432"
+        volumes:
+            - postgres_data:/var/lib/postgresql/data
 
 volumes:
-  postgres_data:
-  mongo_data:
-  redis_data:
-  dynamodb_data:
\ No newline at end of file
+    postgres_data:
+    mongo_data:
+    redis_data:
+    dynamodb_data:

From 7cbfd26affb618312e40dfdb93ac3629f71a6e87 Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Wed, 3 Apr 2024 12:12:52 -0300
Subject: [PATCH 23/34] basic tests for postgres sessions

---
 tests/test_postgresql.py | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 tests/test_postgresql.py

diff --git a/tests/test_postgresql.py b/tests/test_postgresql.py
new file mode 100644
index 00000000..bc6cebf3
--- /dev/null
+++ b/tests/test_postgresql.py
@@ -0,0 +1,30 @@
+import json
+from contextlib import contextmanager
+
+import flask
+import pytest
+from psycopg2.pool import ThreadedConnectionPool
+from sqlalchemy import text
+
+from flask_session.postgres import PostgreSqlSession
+
+TEST_DB = "postgresql://root:pwd@localhost:5433/dummy"
+
+
+class TestPostgreSql:
+    """This requires package: sqlalchemy"""
+
+    @contextmanager
+    def setup_postgresql(self, app_utils):
+        self.pool = ThreadedConnectionPool(1, 5, TEST_DB)
+        self.app = app_utils.create_app(
+            {"SESSION_TYPE": "postgresql", "SESSION_POSTGRESQL": self.pool}
+        )
+
+        yield
+        self.app.session_interface._drop_table()
+
+    def test_postgres(self, app_utils):
+        with self.setup_postgresql(app_utils), self.app.test_request_context():
+            assert isinstance(flask.session, PostgreSqlSession)
+            app_utils.test_session(self.app)

From 7d68f456c83345ccfffee3b1f852ccd28b127458 Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Wed, 3 Apr 2024 12:13:02 -0300
Subject: [PATCH 24/34] bug fixes

---
 src/flask_session/postgres/_queries.py |  6 +++---
 src/flask_session/postgres/postgres.py | 13 +++++++++----
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/src/flask_session/postgres/_queries.py b/src/flask_session/postgres/_queries.py
index 26745764..23fb0101 100644
--- a/src/flask_session/postgres/_queries.py
+++ b/src/flask_session/postgres/_queries.py
@@ -58,7 +58,7 @@ def retrieve_session_data(self) -> str:
     @property
     def upsert_session(self) -> str:
         return sql.SQL(
-            """INSERT INTO {schema}.{table} (session_id, data, ttl)
+            """INSERT INTO {schema}.{table} (session_id, data, expiry)
             VALUES (%(session_id)s, %(data)s, NOW() + %(ttl)s)
             ON CONFLICT (session_id)
             DO UPDATE SET data = %(data)s, expiry = NOW() + %(ttl)s;
@@ -78,7 +78,7 @@ def delete_session(self) -> str:
         ).format(schema=sql.Identifier(self.schema), table=sql.Identifier(self.table))
 
     @property
-    def drop_sessions_table(self) -> None:
-        sql.SQL("DROP TABLE IF EXISTS {schema}.{table};").format(
+    def drop_sessions_table(self) -> str:
+        return sql.SQL("DROP TABLE IF EXISTS {schema}.{table};").format(
             schema=sql.Identifier(self.schema), table=sql.Identifier(self.table)
         )
diff --git a/src/flask_session/postgres/postgres.py b/src/flask_session/postgres/postgres.py
index 3ebbbbcb..48ed3340 100644
--- a/src/flask_session/postgres/postgres.py
+++ b/src/flask_session/postgres/postgres.py
@@ -103,7 +103,7 @@ def _delete_session(self, store_id: str) -> None:
         with self._get_cursor() as cur:
             cur.execute(
                 self._queries.delete_session,
-                dict(session_id=self._get_store_id(store_id)),
+                dict(session_id=store_id),
             )
 
     @retry_query(max_attempts=3)
@@ -111,12 +111,12 @@ def _retrieve_session_data(self, store_id: str) -> dict | None:
         with self._get_cursor() as cur:
             cur.execute(
                 self._queries.retrieve_session_data,
-                dict(session_id=self._get_store_id(store_id)),
+                dict(session_id=store_id),
             )
             session_data = cur.fetchone()
 
         if session_data is not None:
-            serialized_session_data = want_bytes(session_data)
+            serialized_session_data = want_bytes(session_data[0])
             return self.serializer.decode(serialized_session_data)
         return None
 
@@ -128,7 +128,7 @@ def _upsert_session(
         serialized_session_data = self.serializer.encode(session)
 
         if session.sid is not None:
-            assert session.sid == store_id
+            assert session.sid == store_id.removeprefix(self.key_prefix)
 
         with self._get_cursor() as cur:
             cur.execute(
@@ -139,3 +139,8 @@ def _upsert_session(
                     ttl=session_lifetime,
                 ),
             )
+
+    def _drop_table(self):
+        with self._get_cursor() as cur:
+            print(self._queries.drop_sessions_table)
+            cur.execute(self._queries.drop_sessions_table)

From 297eaa175b527e4b7dd6829d328feebe95ec287b Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Wed, 3 Apr 2024 12:25:01 -0300
Subject: [PATCH 25/34] add cookie test

---
 tests/test_postgresql.py | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/tests/test_postgresql.py b/tests/test_postgresql.py
index bc6cebf3..0d52e84a 100644
--- a/tests/test_postgresql.py
+++ b/tests/test_postgresql.py
@@ -2,9 +2,8 @@
 from contextlib import contextmanager
 
 import flask
-import pytest
+from itsdangerous import want_bytes
 from psycopg2.pool import ThreadedConnectionPool
-from sqlalchemy import text
 
 from flask_session.postgres import PostgreSqlSession
 
@@ -24,7 +23,28 @@ def setup_postgresql(self, app_utils):
         yield
         self.app.session_interface._drop_table()
 
+    def retrieve_stored_session(self, key):
+        with self.app.session_interface._get_cursor() as cur:
+            cur.execute(
+                self.app.session_interface._queries.retrieve_session_data,
+                dict(session_id=key),
+            )
+
+            session_data = cur.fetchone()
+        if session_data is not None:
+            return want_bytes(session_data[0].tobytes())
+        return None
+
     def test_postgres(self, app_utils):
         with self.setup_postgresql(app_utils), self.app.test_request_context():
             assert isinstance(flask.session, PostgreSqlSession)
             app_utils.test_session(self.app)
+
+            # Check if the session is stored in MongoDB
+            cookie = app_utils.test_session_with_cookie(self.app)
+            session_id = cookie.split(";")[0].split("=")[1]
+            byte_string = self.retrieve_stored_session(f"session:{session_id}")
+            stored_session = (
+                json.loads(byte_string.decode("utf-8")) if byte_string else {}
+            )
+            assert stored_session.get("value") == "44"

From b4f488d9ef217ff4456b5dea8f1d9907f3a7018c Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Wed, 3 Apr 2024 15:40:18 -0300
Subject: [PATCH 26/34] add postgres service to test gh actions

---
 .github/workflows/test.yaml | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index 3b57e6e9..2351b7d4 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -15,6 +15,21 @@ jobs:
                 image: amazon/dynamodb-local
                 ports:
                     - 8000:8000
+
+            postgresql:
+                image: postgres:latest
+                ports:
+                    - 5433:5432
+                env:
+                    POSTGRES_PASSWORD: pwd
+                    POSTGRES_USER: root
+                    POSTGRES_DB: dummy
+                # Set health checks to wait until postgres has started
+                options: >-
+                    --health-cmd pg_isready
+                    --health-interval 10s
+                    --health-timeout 5s
+                    --health-retries 5
         steps:
             - uses: actions/checkout@v4
             - uses: supercharge/redis-github-action@1.5.0

From 616edd06d2e9f9f84e591bad2603170e12a5eeef Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Wed, 3 Apr 2024 16:33:21 -0300
Subject: [PATCH 27/34] undo formatting changes

---
 docker-compose.yml | 80 +++++++++++++++++++++++-----------------------
 pyproject.toml     | 10 +++---
 2 files changed, 46 insertions(+), 44 deletions(-)

diff --git a/docker-compose.yml b/docker-compose.yml
index 543ec039..3463412d 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -1,48 +1,48 @@
-version: "3.8"
+version: '3.8'
 
 services:
-    dynamodb-local:
-        image: "amazon/dynamodb-local:latest"
-        container_name: dynamodb-local
-        ports:
-            - "8000:8000"
-        environment:
-            - AWS_ACCESS_KEY_ID=dummy
-            - AWS_SECRET_ACCESS_KEY=dummy
-            - AWS_DEFAULT_REGION=us-west-2
+  dynamodb-local:
+    image: "amazon/dynamodb-local:latest"
+    container_name: dynamodb-local
+    ports:
+      - "8000:8000"
+    environment:
+      - AWS_ACCESS_KEY_ID=dummy
+      - AWS_SECRET_ACCESS_KEY=dummy
+      - AWS_DEFAULT_REGION=us-west-2
 
-    mongo:
-        image: mongo:latest
-        ports:
-            - "27017:27017"
-        volumes:
-            - mongo_data:/data/db
+  mongo:
+    image: mongo:latest
+    ports:
+      - "27017:27017"
+    volumes:
+      - mongo_data:/data/db
 
-    redis:
-        image: redis:latest
-        ports:
-            - "6379:6379"
-        volumes:
-            - redis_data:/data
+  redis:
+    image: redis:latest
+    ports:
+      - "6379:6379"
+    volumes:
+      - redis_data:/data
 
-    memcached:
-        image: memcached:latest
-        ports:
-            - "11211:11211"
+  memcached:
+    image: memcached:latest
+    ports:
+      - "11211:11211"
 
-    postgres:
-        image: postgres:latest
-        environment:
-            - POSTGRES_USER=root
-            - POSTGRES_PASSWORD=pwd
-            - POSTGRES_DB=dummy
-        ports:
-            - "5433:5432"
-        volumes:
-            - postgres_data:/var/lib/postgresql/data
+  postgres:
+    image: postgres:latest
+    environment:
+      - POSTGRES_USER=root
+      - POSTGRES_PASSWORD=pwd
+      - POSTGRES_DB=dummy
+    ports:
+      - "5433:5432"
+    volumes:
+      - postgres_data:/var/lib/postgresql/data
 
 volumes:
-    postgres_data:
-    mongo_data:
-    redis_data:
-    dynamodb_data:
+  postgres_data:
+  mongo_data:
+  redis_data:
+  dynamodb_data:
\ No newline at end of file
diff --git a/pyproject.toml b/pyproject.toml
index b14321d4..b66f1cc3 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -3,9 +3,7 @@ name = "Flask-Session"
 description = "Server-side session support for Flask"
 readme = "README.md"
 license = { text = "BSD-3-Clause" }
-maintainers = [
-    { name = "Pallets Community Ecosystem", email = "contact@palletsprojects.com" },
-]
+maintainers = [{ name = "Pallets Community Ecosystem", email = "contact@palletsprojects.com" }]
 authors = [{ name = "Shipeng Feng", email = "fsp261@gmail.com" }]
 classifiers = [
     "Development Status :: 4 - Beta",
@@ -21,7 +19,11 @@ classifiers = [
     "Topic :: Software Development :: Libraries :: Application Frameworks",
 ]
 requires-python = ">=3.8"
-dependencies = ["flask>=2.2", "msgspec>=0.18.6", "cachelib"]
+dependencies = [
+    "flask>=2.2", 
+    "msgspec>=0.18.6", 
+    "cachelib"
+]
 dynamic = ["version"]
 
 [project.urls]

From 563d5a4f566874225820250e881fb9a38a497201 Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Wed, 3 Apr 2024 16:34:55 -0300
Subject: [PATCH 28/34] rename postgres -> postgresql

---
 docs/api.rst                                                  | 2 +-
 src/flask_session/{postgres => postgresql}/__init__.py        | 0
 src/flask_session/{postgres => postgresql}/_queries.py        | 0
 .../{postgres/postgres.py => postgresql/postgresql.py}        | 0
 tests/test_postgresql.py                                      | 4 ++--
 5 files changed, 3 insertions(+), 3 deletions(-)
 rename src/flask_session/{postgres => postgresql}/__init__.py (100%)
 rename src/flask_session/{postgres => postgresql}/_queries.py (100%)
 rename src/flask_session/{postgres/postgres.py => postgresql/postgresql.py} (100%)

diff --git a/docs/api.rst b/docs/api.rst
index 31e1e2b1..faae610d 100644
--- a/docs/api.rst
+++ b/docs/api.rst
@@ -21,4 +21,4 @@ Anything documented here is part of the public API that Flask-Session provides,
 .. autoclass:: flask_session.mongodb.MongoDBSessionInterface
 .. autoclass:: flask_session.sqlalchemy.SqlAlchemySessionInterface
 .. autoclass:: flask_session.dynamodb.DynamoDBSessionInterface
-.. autoclass:: flask_session.postgres.PostgreSqlSessionInterface
\ No newline at end of file
+.. autoclass:: flask_session.postgresql.PostgreSqlSessionInterface
\ No newline at end of file
diff --git a/src/flask_session/postgres/__init__.py b/src/flask_session/postgresql/__init__.py
similarity index 100%
rename from src/flask_session/postgres/__init__.py
rename to src/flask_session/postgresql/__init__.py
diff --git a/src/flask_session/postgres/_queries.py b/src/flask_session/postgresql/_queries.py
similarity index 100%
rename from src/flask_session/postgres/_queries.py
rename to src/flask_session/postgresql/_queries.py
diff --git a/src/flask_session/postgres/postgres.py b/src/flask_session/postgresql/postgresql.py
similarity index 100%
rename from src/flask_session/postgres/postgres.py
rename to src/flask_session/postgresql/postgresql.py
diff --git a/tests/test_postgresql.py b/tests/test_postgresql.py
index 0d52e84a..05a9e555 100644
--- a/tests/test_postgresql.py
+++ b/tests/test_postgresql.py
@@ -5,7 +5,7 @@
 from itsdangerous import want_bytes
 from psycopg2.pool import ThreadedConnectionPool
 
-from flask_session.postgres import PostgreSqlSession
+from flask_session.postgresql import PostgreSqlSession
 
 TEST_DB = "postgresql://root:pwd@localhost:5433/dummy"
 
@@ -35,7 +35,7 @@ def retrieve_stored_session(self, key):
             return want_bytes(session_data[0].tobytes())
         return None
 
-    def test_postgres(self, app_utils):
+    def test_postgresql(self, app_utils):
         with self.setup_postgresql(app_utils), self.app.test_request_context():
             assert isinstance(flask.session, PostgreSqlSession)
             app_utils.test_session(self.app)

From db586abcc84a3a1e63c10abf62163b713e68f61a Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Wed, 3 Apr 2024 16:36:25 -0300
Subject: [PATCH 29/34] undo formatting changes

---
 pyproject.toml                           | 6 +++---
 src/flask_session/__init__.py            | 2 +-
 src/flask_session/postgresql/__init__.py | 2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/pyproject.toml b/pyproject.toml
index b66f1cc3..5db4a0e5 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -2,9 +2,9 @@
 name = "Flask-Session"
 description = "Server-side session support for Flask"
 readme = "README.md"
-license = { text = "BSD-3-Clause" }
-maintainers = [{ name = "Pallets Community Ecosystem", email = "contact@palletsprojects.com" }]
-authors = [{ name = "Shipeng Feng", email = "fsp261@gmail.com" }]
+license = {text = "BSD-3-Clause"}
+maintainers = [{name = "Pallets Community Ecosystem", email = "contact@palletsprojects.com"}]
+authors = [{name = "Shipeng Feng", email = "fsp261@gmail.com"}]
 classifiers = [
     "Development Status :: 4 - Beta",
     "Environment :: Web Environment",
diff --git a/src/flask_session/__init__.py b/src/flask_session/__init__.py
index 25dff6ba..f527beb5 100644
--- a/src/flask_session/__init__.py
+++ b/src/flask_session/__init__.py
@@ -194,7 +194,7 @@ def _get_interface(self, app):
             )
 
         elif SESSION_TYPE == "postgresql":
-            from .postgres import PostgreSqlSessionInterface
+            from .postgresql import PostgreSqlSessionInterface
 
             session_interface = PostgreSqlSessionInterface(
                 **common_params,
diff --git a/src/flask_session/postgresql/__init__.py b/src/flask_session/postgresql/__init__.py
index f78d9a79..0d51b3a8 100644
--- a/src/flask_session/postgresql/__init__.py
+++ b/src/flask_session/postgresql/__init__.py
@@ -1 +1 @@
-from .postgres import PostgreSqlSession, PostgreSqlSessionInterface  # noqa: F401
+from .postgresql import PostgreSqlSession, PostgreSqlSessionInterface  # noqa: F401

From 38c1d8165eb8739f19e2566a11448719f3dcb4ba Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Wed, 3 Apr 2024 16:36:56 -0300
Subject: [PATCH 30/34] undo formatting changes

---
 pyproject.toml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pyproject.toml b/pyproject.toml
index 5db4a0e5..f4aaed36 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -20,8 +20,8 @@ classifiers = [
 ]
 requires-python = ">=3.8"
 dependencies = [
-    "flask>=2.2", 
-    "msgspec>=0.18.6", 
+    "flask>=2.2",
+    "msgspec>=0.18.6",
     "cachelib"
 ]
 dynamic = ["version"]

From ab21ea1a620c54671c0c7b96b5a80e4508ddc155 Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Wed, 3 Apr 2024 16:39:37 -0300
Subject: [PATCH 31/34] undo formatting changes

---
 pyproject.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pyproject.toml b/pyproject.toml
index f4aaed36..da444405 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -22,7 +22,7 @@ requires-python = ">=3.8"
 dependencies = [
     "flask>=2.2",
     "msgspec>=0.18.6",
-    "cachelib"
+    "cachelib",
 ]
 dynamic = ["version"]
 

From bd4623c2eb9df9ffd9a6812f09926a97cdef3615 Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Wed, 3 Apr 2024 16:40:00 -0300
Subject: [PATCH 32/34] remove debug print statement

---
 src/flask_session/postgresql/postgresql.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/flask_session/postgresql/postgresql.py b/src/flask_session/postgresql/postgresql.py
index 48ed3340..e85bd537 100644
--- a/src/flask_session/postgresql/postgresql.py
+++ b/src/flask_session/postgresql/postgresql.py
@@ -142,5 +142,4 @@ def _upsert_session(
 
     def _drop_table(self):
         with self._get_cursor() as cur:
-            print(self._queries.drop_sessions_table)
             cur.execute(self._queries.drop_sessions_table)

From bb4259bf24cd020ff3d247d105c2115375af5234 Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Tue, 16 Apr 2024 08:34:24 -0300
Subject: [PATCH 33/34] replace pipes in type annotations with Optional

---
 src/flask_session/postgresql/postgresql.py | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/flask_session/postgresql/postgresql.py b/src/flask_session/postgresql/postgresql.py
index e85bd537..b5f1e8d6 100644
--- a/src/flask_session/postgresql/postgresql.py
+++ b/src/flask_session/postgresql/postgresql.py
@@ -2,7 +2,7 @@
 
 from contextlib import contextmanager
 from datetime import timedelta as TimeDelta
-from typing import Generator
+from typing import Generator, Optional
 
 from flask import Flask
 from itsdangerous import want_bytes
@@ -40,7 +40,7 @@ class PostgreSqlSessionInterface(ServerSideSessionInterface):
     def __init__(
         self,
         app: Flask,
-        pool: ThreadedConnectionPool | None = Defaults.SESSION_POSTGRESQL,
+        pool: Optional[ThreadedConnectionPool] = Defaults.SESSION_POSTGRESQL,
         key_prefix: str = Defaults.SESSION_KEY_PREFIX,
         use_signer: bool = Defaults.SESSION_USE_SIGNER,
         permanent: bool = Defaults.SESSION_PERMANENT,
@@ -48,7 +48,7 @@ def __init__(
         serialization_format: str = Defaults.SESSION_SERIALIZATION_FORMAT,
         table: str = Defaults.SESSION_POSTGRESQL_TABLE,
         schema: str = Defaults.SESSION_POSTGRESQL_SCHEMA,
-        cleanup_n_requests: int | None = Defaults.SESSION_CLEANUP_N_REQUESTS,
+        cleanup_n_requests: Optional[int] = Defaults.SESSION_CLEANUP_N_REQUESTS,
     ) -> None:
         if not isinstance(pool, ThreadedConnectionPool):
             raise TypeError("No valid ThreadedConnectionPool instance provided.")
@@ -74,7 +74,7 @@ def __init__(
 
     @contextmanager
     def _get_cursor(
-        self, conn: PsycoPg2Connection | None = None
+        self, conn: Optional[PsycoPg2Connection] = None
     ) -> Generator[PsycoPg2Cursor, None, None]:
         _conn: PsycoPg2Connection = conn or self.pool.getconn()
 
@@ -107,7 +107,7 @@ def _delete_session(self, store_id: str) -> None:
             )
 
     @retry_query(max_attempts=3)
-    def _retrieve_session_data(self, store_id: str) -> dict | None:
+    def _retrieve_session_data(self, store_id: str) -> Optional[dict]:
         with self._get_cursor() as cur:
             cur.execute(
                 self._queries.retrieve_session_data,

From 1108c74c5103438d1ed8c9edacd23ea15408139d Mon Sep 17 00:00:00 2001
From: Giuseppe Papallo <giuseppe@papallo.it>
Date: Tue, 16 Apr 2024 08:35:02 -0300
Subject: [PATCH 34/34] fix missing return type

---
 src/flask_session/postgresql/postgresql.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/flask_session/postgresql/postgresql.py b/src/flask_session/postgresql/postgresql.py
index b5f1e8d6..9ad198bb 100644
--- a/src/flask_session/postgresql/postgresql.py
+++ b/src/flask_session/postgresql/postgresql.py
@@ -140,6 +140,6 @@ def _upsert_session(
                 ),
             )
 
-    def _drop_table(self):
+    def _drop_table(self) -> None:
         with self._get_cursor() as cur:
             cur.execute(self._queries.drop_sessions_table)