sql tuning and migrations

src/SqlUpdate/2017-16-03_01_CipherMigration.sql

@@ -1,3 +1,5 @@
+-- Step 1, Run each statement individually
+
 insert into folder
 select Id, UserId, JSON_VALUE(Data,'$.Name') AS [Name], CreationDate, RevisionDate
 from cipher
@@ -12,3 +14,20 @@ insert into favorite
 select UserId, [Id]
 from cipher
 where Favorite = 1
+
+
+-- Step 2, drop each column
+
+alter table cipher drop constraint [FK_Cipher_Folder]
+go
+
+alter table cipher drop column FolderId
+go
+
+alter table cipher drop column Favorite
+go
+
+-- Step 3, delete old folder ciphers
+
+delete from cipher where [type] = 0
+