modified data moddel, to support non static use of the model

src/music_kraken/database/data_models.py

@@ -1,4 +1,4 @@
-from typing import List, Union, Type
+from typing import List, Union, Type, Optional
 from peewee import (
     SqliteDatabase,
     PostgresqlDatabase,
@@ -11,6 +11,18 @@ from peewee import (
     TextField
 )
 
+"""
+**IMPORTANT**:
+
+never delete, modify the datatype or add constrains to ANY existing collumns,
+between the versions, that gets pushed out to the users.
+Else my function can't update legacy databases, to new databases, 
+while keeping the data of the old ones.
+
+EVEN if that means to for example keep decimal values stored in strings.
+(not in my codebase though.)
+"""
+
 
 class BaseModel(Model):
     class Meta:
@@ -26,7 +38,6 @@ class BaseModel(Model):
         return self
 
 
-
 class Album(BaseModel):
     """A class representing an album in the music database."""
 
@@ -120,8 +131,19 @@ class AlbumArtist(BaseModel):
     artist: ForeignKeyField = ForeignKeyField(Artist, backref='album_artists')
 
 
+ALL_MODELS = [
+    Song, 
+    Album, 
+    Artist,
+    Source,
+    Lyrics,
+    AlbumArtist,
+    Target,
+    SongArtist
+]
 
 
+if __name__ == "__main__":
     database_1 = SqliteDatabase(":memory:")
     database_1.create_tables([Song.Use(database_1)])
     database_2 = SqliteDatabase(":memory:")
@@ -141,4 +163,3 @@ for song in Song.Use(database_1).select():
     print("database 2")
     for song in Song.Use(database_1).select():
         print(song.name)
-

src/music_kraken/database/database.py

@@ -75,5 +75,22 @@ class Database:
         create tables if they don't exist.
         """
         self.database = self.create_database()
-
         self.database.connect()
+
+        self.database.create_tables(data_models.ALL_MODELS, safe=True)
+
+        """
+        upgrade old databases. 
+        If a collumn has been added in a new version this adds it to old Tables, 
+        without deleting the data in legacy databases
+        """
+        for model in data_models.ALL_MODELS:
+            for field_name, field_obj in model._meta.fields.items():
+                # check if the field exists in the database
+                if not self.database.table_column_exists(model._meta.db_table, field_name):
+                    # add the missing column to the table
+                    self.database.add_column(model._meta.db_table, field_name, field_obj)
+
+
+    def __del__(self):
+        self.database.close()