Fixes for sqlalchemy version 2.x (reported upstream)
--- a/cli/dbtools.py
+++ b/cli/dbtools.py
@@ -10,6 +10,7 @@
 import string
 from datetime import datetime
 from getpass import getpass
+from sqlalchemy import text
 
 passwordChars = string.ascii_letters+string.digits+'!"#$%&()*+-/;<=>?[]_{|}~'
 defaultPassLength = 16
@@ -87,7 +88,7 @@
         user = Users.query.filter(Users.ID == 0).first()
         if user is None:
             cli.print("System admin user not found, creating...")
-            DB.session.execute("SET sql_mode='NO_AUTO_VALUE_ON_ZERO';")
+            DB.session.execute(text("SET sql_mode='NO_AUTO_VALUE_ON_ZERO';"))
             user, _ = createAdmin()
             DB.session.add(user)
     cli.print("Setting password for user '{}'".format(user.username))
--- a/orm/__init__.py
+++ b/orm/__init__.py
@@ -4,10 +4,10 @@
 
 __all__ = ["domains", "misc", "users", "ext"]
 
+import sqlalchemy
 from sqlalchemy import create_engine, event, select, text
 from sqlalchemy.exc import OperationalError
-from sqlalchemy.ext.declarative import declarative_base
-from sqlalchemy.orm import scoped_session, sessionmaker, class_mapper, Query, column_property
+from sqlalchemy.orm import declarative_base, scoped_session, sessionmaker, class_mapper, Query, column_property
 
 from tools.config import Config
 
@@ -44,7 +44,7 @@
 
     def testConnection(self, verbose=False):
         try:
-            self.session.execute("SELECT 1 FROM DUAL")
+            self.session.execute(text("SELECT 1 FROM DUAL"))
         except OperationalError as err:
             self.session.remove()
             return "Database connection failed with error {}: {}".format(err.orig.args[0], err.orig.args[1])
@@ -64,7 +64,7 @@
             Version number or None on failure
         """
         try:
-            version = int(self.session.execute("SELECT `value` FROM `options` WHERE `key` = 'schemaversion'").fetchone()[0])
+            version = int(self.session.execute(text("SELECT `value` FROM `options` WHERE `key` = 'schemaversion'")).fetchone()[0])
             if verbose:
                 logger.info("Detected database schema version n"+str(version))
             return version
@@ -216,7 +216,10 @@
     column : Any
         Column definition to return if version check passes
     """
-    return column if DB.minVersion(version) else column_property(select([text(default)]).as_scalar())
+    if sqlalchemy.__version__.split(".") >= ["1", "4"]:
+        return column if DB.minVersion(version) else column_property(select(text(default)).scalar_subquery())
+    else:
+        return column if DB.minVersion(version) else column_property(select([text(default)]).as_scalar())
 
 
 class NotifyTable:
--- a/orm/domains.py
+++ b/orm/domains.py
@@ -418,18 +418,18 @@
 
 if sqlalchemy.__version__.split(".") >= ["1", "4"]:
     inspect(Domains).add_property("activeUsers",
-                                  column_property(select([func.count(Users.ID)])
+                                  column_property(select(func.count(Users.ID))
                                                   .where(Users.domainID == Domains.ID, Users.addressStatus == Users.NORMAL,
                                                          Users.maildir != "")
                                                   .scalar_subquery()))
     inspect(Domains).add_property("inactiveUsers",
-                                  column_property(select([func.count(Users.ID)])
+                                  column_property(select(func.count(Users.ID))
                                                   .where(Users.domainID == Domains.ID,
                                                          Users.addressStatus.not_in((Users.NORMAL, Users.SHARED)),
                                                          Users.maildir != "")
                                                   .scalar_subquery()))
     inspect(Domains).add_property("virtualUsers",
-                                  column_property(select([func.count(Users.ID)])
+                                  column_property(select(func.count(Users.ID))
                                                   .where(Users.domainID == Domains.ID, (Users.addressStatus == Users.SHARED) |
                                                          (Users.maildir == ""))
                                                   .scalar_subquery()))
--- a/orm/misc.py
+++ b/orm/misc.py
@@ -164,7 +164,10 @@
     @users.expression
     def users(cls):
         from .users import Users
-        return select([func.count(Users.ID)]).where(Users.homeserverID == cls.ID).as_scalar()
+        if sqlalchemy.__version__.split(".") >= ["1", "4"]:
+            return select(func.count(Users.ID)).where(Users.homeserverID == cls.ID).scalar_subquery()
+        else:
+            return select([func.count(Users.ID)]).where(Users.homeserverID == cls.ID).as_scalar()
 
     @hybrid_property
     def domains(self):
@@ -174,7 +177,10 @@
     @domains.expression
     def domains(cls):
         from .domains import Domains
-        return select([func.count(Domains.ID)]).where(Domains.homeserverID == cls.ID).as_scalar()
+        if sqlalchemy.__version__.split(".") >= ["1", "4"]:
+            return select(func.count(Domains.ID)).where(Domains.homeserverID == cls.ID).scalar_subquery()
+        else:
+            return select([func.count(Domains.ID)]).where(Domains.homeserverID == cls.ID).as_scalar()
 
     @staticmethod
     def _getServer(objID, serverID=None, domain=False):