DB schema: Cleaner upgrades, fix column order

src/gpodder/schema.py

@@ -65,6 +65,25 @@
 
 CURRENT_VERSION = 3
 
+
+# SQL commands to upgrade old database versions to new ones
+# Each item is a tuple (old_version, new_version, sql_commands) that should be
+# applied to the database to migrate from old_version to new_version.
+UPGRADE_SQL = [
+        # Version 2: Section labels for the podcast list
+        (1, 2, """
+        ALTER TABLE podcast ADD COLUMN section TEXT NOT NULL DEFAULT ''
+        """),
+
+        # Version 3: Flattr integration (+ invalidate http_* fields to force
+        # a feed update, so that payment URLs are parsed during the next check)
+        (2, 3, """
+        ALTER TABLE podcast ADD COLUMN payment_url TEXT NULL DEFAULT NULL
+        ALTER TABLE episode ADD COLUMN payment_url TEXT NULL DEFAULT NULL
+        UPDATE podcast SET http_last_modified=NULL, http_etag=NULL
+        """),
+]
+
 def initialize_database(db):
     # Create table for podcasts
     db.execute("""
@@ -75,15 +94,15 @@ def initialize_database(db):
         link TEXT NOT NULL DEFAULT '',
         description TEXT NOT NULL DEFAULT '',
         cover_url TEXT NULL DEFAULT NULL,
-        payment_url TEXT NULL DEFAULT NULL,
         auth_username TEXT NULL DEFAULT NULL,
         auth_password TEXT NULL DEFAULT NULL,
         http_last_modified TEXT NULL DEFAULT NULL,
         http_etag TEXT NULL DEFAULT NULL,
         auto_archive_episodes INTEGER NOT NULL DEFAULT 0,
         download_folder TEXT NOT NULL DEFAULT '',
         pause_subscription INTEGER NOT NULL DEFAULT 0,
-        section TEXT NOT NULL DEFAULT ''
+        section TEXT NOT NULL DEFAULT '',
+        payment_url TEXT NULL DEFAULT NULL
     )
     """)
 
@@ -103,7 +122,6 @@ def initialize_database(db):
         title TEXT NOT NULL DEFAULT '',
         description TEXT NOT NULL DEFAULT '',
         url TEXT NOT NULL,
-        payment_url TEXT NULL DEFAULT NULL,
         published INTEGER NOT NULL DEFAULT 0,
         guid TEXT NOT NULL,
         link TEXT NOT NULL DEFAULT '',
@@ -116,7 +134,8 @@ def initialize_database(db):
         total_time INTEGER NOT NULL DEFAULT 0,
         current_position INTEGER NOT NULL DEFAULT 0,
         current_position_updated INTEGER NOT NULL DEFAULT 0,
-        last_playback INTEGER NOT NULL DEFAULT 0
+        last_playback INTEGER NOT NULL DEFAULT 0,
+        payment_url TEXT NULL DEFAULT NULL
     )
     """)
 
@@ -157,27 +176,13 @@ def upgrade(db, filename):
 
     db.execute("DELETE FROM version")
 
-    if version == 1:
-        UPGRADE_V1_TO_V2 = """
-        ALTER TABLE podcast ADD COLUMN section TEXT NOT NULL DEFAULT ''
-        """
-
-        for sql in UPGRADE_V1_TO_V2.strip().split('\n'):
-            db.execute(sql)
-
-        version = 2
-
-    if version == 2:
-        UPGRADE_V2_TO_V3 = """
-        ALTER TABLE podcast ADD COLUMN payment_url TEXT NULL DEFAULT NULL;
-        ALTER TABLE episode ADD COLUMN payment_url TEXT NULL DEFAULT NULL;
-        UPDATE podcast SET http_last_modified=NULL, http_etag=NULL;
-        """
-
-        for sql in UPGRADE_V2_TO_V3.strip().split('\n'):
-            db.execute(sql)
+    for old_version, new_version, upgrade in UPGRADE_SQL:
+        if version == old_version:
+            for sql in upgrade.strip().split('\n'):
+                db.execute(sql)
+            version = new_version
 
-        version = 3
+    assert version == CURRENT_VERSION
 
     db.execute("INSERT INTO version (version) VALUES (%d)" % version)
     db.commit()
@@ -218,6 +223,7 @@ def convert_gpodder2_db(old_db, new_db):
                 row['foldername'],
                 not row['feed_update_enabled'],
                 '',
+                None,
         )
         new_db.execute("""
         INSERT INTO podcast VALUES (%s)
@@ -248,6 +254,7 @@ def convert_gpodder2_db(old_db, new_db):
                 row['current_position'],
                 row['current_position_updated'],
                 0,
+                None,
         )
         new_db.execute("""
         INSERT INTO episode VALUES (%s)