added migrations

backend/database/Migrations.py

@@ -0,0 +1,31 @@
+from flask_sqlalchemy import SQLAlchemy
+from database.Models import *
+from sqlalchemy.orm import session
+from sqlalchemy import text
+import util
+
+
+def migrate(db: session):
+    current_db_version: KeyValue = db.query(KeyValue).filter_by(
+        key="version").first()
+    print("Current database version:", current_db_version.value)
+
+    migrations = [
+        # Add lists for migrations
+        # E.g ALTER TABLE drink ADD column price6 float DEFAULT 50
+        #["ALTER TABLE drink ADD column price6 float DEFAULT 50"]
+    ]
+
+    if util.CURRENT_VERSION != len(migrations):
+        print("Error: No migration available")
+        exit()
+
+    for migration in migrations[int(current_db_version.value):]:
+        print("Migrating from", current_db_version.value,
+              "to", int(current_db_version.value)+1)
+        for statement in migration:
+            db.execute(text(statement))
+        current_db_version.value = int(current_db_version.value)+1
+        db.commit()
+
+    print("Migrations complete")

backend/database/Queries.py

@@ -16,7 +16,7 @@
 import os
 from sqlalchemy import extract
 from difflib import SequenceMatcher
-from sqlalchemy import inspect, text
+import database.Migrations
 
 
 class Queries:
@@ -27,6 +27,7 @@ def __init__(self, db):
         self.db.create_all()
         if self.session.query(Member).first() is None:
             self.create_dummy_data()
+        database.Migrations.migrate(self.session)
 
     def get_users(self):
         members = self.session.query(Member).all()
@@ -587,12 +588,10 @@ def remove_message(self, message_id):
         reminder: Reminder = self.session.query(
             Reminder).filter_by(id=message_id).first()
 
-
         self.session.delete(reminder)
 
         self.session.commit()
 
-
     def get_username_alias(self, member_id):
         member: Member = self.session.query(
             Member).filter_by(id=member_id).first()
@@ -829,7 +828,8 @@ def create_dummy_data(self) -> None:
             util.moderator_password)
         self.session.add(
             Member(name=util.moderator_username, password=hashedPassword, salt=salt))
-
+        self.session.add(
+            KeyValue(key="version", value=util.CURRENT_VERSION))
         self.session.commit()
 
         if util.token is not None and util.old_domain is not None:

backend/util.py

@@ -70,6 +70,8 @@
 OIDC_USER_NEEDS_VERIFICATION = os.environ.get(
     "OIDC_USER_NEEDS_VERIFICATION") == "true" if os.environ.get("OIDC_USER_NEEDS_VERIFICATION") else True
 
+CURRENT_VERSION = 0
+
 tempfile_path = "tempfiles"
 backup_file_name = "backup.json"