tmp

README.md

@@ -37,7 +37,8 @@ That's all. Now, you can access either http://localhost:3000 or http://host-ip:3
 > [!IMPORTANT] 
 > If you upgrade to major version, you need to read the upgrade guide carefully before upgrade. Because there are some breaking changes in major version.
 > 
-> - See [v3 Upgrade]() for upgrade from v2 release.
+> - See [V3 Upgrade]() for upgrade from V2 release.
+> - See [Edge Upgrade]() for upgrade from edge release to latest stable release.
 
 Upgrade Black Candy is just pull new image from remote. then remove old container and create a new one.
 

docs/v3_upgrade.md

@@ -0,0 +1,17 @@
+# Upgrade from Black Candy v2 to v3
+
+There are a lot of breaking infrastructure changes in Black Candy v3, including using SQLite as the default database, remove the dependency on Redis and Sidekiq. Also remove the dependencies of Nginx and Docker Compose to running Black Candy server.
+
+Because Black Candy v3 support both SQLite and PostgreSQL as database, and Blakc Candy v2 only support PostgreSQL. So depending on whether you want to migrate to SQLite as database in v3, you can choose different upgrade methods. 
+
+## Keep using PostgreSQL as database
+
+> [!WARNING]
+> Because Black Candy v3 need to support both SQLite and PostgreSQL, and some data in v2 is not compatible with SQLite, if you keep using PostgreSQL as database, there are still some small data you are going to lose after upgrade. Including: all settings.
+
+1. Pull the v3 image from remote:
+
+```shell
+docker pull ghcr.io/blackcandy-org/blackcandy:3.0.0
+```
+