Lots of changes to the cmap stuff

private/migrations.rkt

@@ -20,7 +20,7 @@
 ;; Supporting functions
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
-(define current-schema-version 11)
+(define current-schema-version 12)
 
 (define schema-1-statements
   (list
@@ -384,6 +384,43 @@ SQL
               )
   (record-schema-version! db 11))
 
+(define (migrate-11->12! db)
+  ;; Older clients stored both automatic and explicit saves as `edit`. Preserve
+  ;; the explicit saves, discard redundant autosave copies, and enforce the new
+  ;; five-item manual history limit per CMap.
+  (query-exec db
+              #<<SQL
+UPDATE concept_map_versions
+SET action = 'manual'
+WHERE action = 'edit'
+  AND summary IN ('Manual save', 'Handmatig opgeslagen')
+SQL
+              )
+  (query-exec db
+              #<<SQL
+DELETE FROM concept_map_versions
+WHERE action = 'edit'
+  AND summary IN ('Automatic save', 'Automatisch opgeslagen')
+SQL
+              )
+  (query-exec db
+              #<<SQL
+WITH ranked AS (
+  SELECT id,
+         row_number() OVER (
+           PARTITION BY concept_map_id
+           ORDER BY version DESC
+         ) AS position
+  FROM concept_map_versions
+  WHERE action = 'manual'
+)
+DELETE FROM concept_map_versions cmv
+USING ranked
+WHERE cmv.id = ranked.id AND ranked.position > 5
+SQL
+              )
+  (record-schema-version! db 12))
+
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ; goal   : Bring a racket-wiki PostgreSQL database to the current schema.
 ; pre    : db is a writable PostgreSQL connection and config identifies the
@@ -428,6 +465,9 @@ SQL
      (define after-user-profiles (database-schema-version db))
      (when (= after-user-profiles 10)
        (migrate-10->11! db))
+     (define after-concept-map-history (database-schema-version db))
+     (when (= after-concept-map-history 11)
+       (migrate-11->12! db))
      (define resulting-version (database-schema-version db))
      (when (> resulting-version current-schema-version)
        (error 'migrate-database!