diff --git a/supysonic/schema/migration/mysql/20190915.sql b/supysonic/schema/migration/mysql/20190915.sql
index 6b258e4..664fd3d 100644
--- a/supysonic/schema/migration/mysql/20190915.sql
+++ b/supysonic/schema/migration/mysql/20190915.sql
@@ -15,47 +15,46 @@ DROP INDEX index_rating_folder_rated_id_fk ON rating_folder;
 
 
 ALTER TABLE folder
-    ADD int_id INTEGER AFTER id,
+    ADD int_id INTEGER REFERENCES folder AFTER id,
     ADD int_parent_id INTEGER REFERENCES folder AFTER parent_id;
-UPDATE folder SET int_id = (SELECT id FROM folder_id_to_int WHERE uuid == folder.id);
-UPDATE folder SET int_parent_id = (SELECT id FROM folder_id_to_int WHERE uuid == folder.parent_id);
+UPDATE folder SET int_id = (SELECT id FROM folder_id_to_int WHERE uuid = folder.id);
+UPDATE folder SET int_parent_id = (SELECT id FROM folder_id_to_int WHERE uuid = folder.parent_id);
 ALTER TABLE folder
     DROP PRIMARY KEY,
     DROP COLUMN id,
     DROP COLUMN parent_id,
-    RENAME COLUMN int_id TO id,
-    RENAME COLUMN int_parent_id TO parent_id,
-    MODIFY id INTEGER AUTO_INCREMENT,
+    CHANGE COLUMN int_id id INTEGER AUTO_INCREMENT,
+    CHANGE COLUMN int_parent_id parent_id INTEGER,
     ADD PRIMARY KEY (id);
 
 
 ALTER TABLE track
     ADD int_root_folder_id INTEGER NOT NULL REFERENCES folder AFTER root_folder_id,
     ADD int_folder_id INTEGER NOT NULL REFERENCES folder AFTER folder_id;
-UPDATE track SET int_root_folder_id = (SELECT id FROM folder_id_to_int WHERE uuid == track.root_folder_id);
-UPDATE track SET int_folder_id = (SELECT id FROM folder_id_to_int WHERE uuid == track.folder_id);
+UPDATE track SET int_root_folder_id = (SELECT id FROM folder_id_to_int WHERE uuid = track.root_folder_id);
+UPDATE track SET int_folder_id = (SELECT id FROM folder_id_to_int WHERE uuid = track.folder_id);
 ALTER TABLE track
     DROP COLUMN root_folder_id,
     DROP COLUMN folder_id,
-    RENAME COLUMN int_root_folder_id TO root_folder_id,
-    RENAME COLUMN int_folder_id TO folder_id,
+    CHANGE COLUMN int_root_folder_id root_folder_id INTEGER NOT NULL,
+    CHANGE COLUMN int_folder_id folder_id INTEGER NOT NULL;
 
 
 ALTER TABLE starred_folder ADD int_starred_id INTEGER NOT NULL REFERENCES folder AFTER starred_id;
-UPDATE starred_folder SET int_starred_id = (SELECT id FROM folder_id_to_int WHERE uuid == starred_folder.starred_id);
+UPDATE starred_folder SET int_starred_id = (SELECT id FROM folder_id_to_int WHERE uuid = starred_folder.starred_id);
 ALTER TABLE starred_folder
     DROP PRIMARY KEY,
     DROP COLUMN starred_id,
-    RENAME COLUMN int_starred_id TO starred_id,
+    CHANGE COLUMN int_starred_id starred_id INTEGER NOT NULL,
     ADD PRIMARY KEY (user_id, starred_id);
 
 
 ALTER TABLE rating_folder ADD int_rated_id INTEGER NOT NULL REFERENCES folder AFTER rated_id;
-UPDATE rating_folder SET int_rated_id = (SELECT id FROM folder_id_to_int WHERE uuid == rating_folder.rated_id);
+UPDATE rating_folder SET int_rated_id = (SELECT id FROM folder_id_to_int WHERE uuid = rating_folder.rated_id);
 ALTER TABLE rating_folder
     DROP PRIMARY KEY,
     DROP COLUMN rated_id,
-    RENAME COLUMN int_rated_id TO rated_id,
+    CHANGE COLUMN int_rated_id rated_id INTEGER NOT NULL,
     ADD PRIMARY KEY (user_id, rated_id);