From d323657047afa58a7cec83e79445c6d949dbc3eb Mon Sep 17 00:00:00 2001
From: Jonas L <jooola@users.noreply.github.com>
Date: Thu, 7 Jul 2022 23:35:27 +0200
Subject: [PATCH] fix: prevent data loose on track_types_id migration (#1949)

---
 .../migrations/0035_3_0_0_alpha_13_9.py       | 27 ++++++++++++-------
 docs/releases/unreleased.md                   |  6 +++--
 2 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/api/libretime_api/legacy/migrations/0035_3_0_0_alpha_13_9.py b/api/libretime_api/legacy/migrations/0035_3_0_0_alpha_13_9.py
index 3d6c2bbad..5a5178294 100644
--- a/api/libretime_api/legacy/migrations/0035_3_0_0_alpha_13_9.py
+++ b/api/libretime_api/legacy/migrations/0035_3_0_0_alpha_13_9.py
@@ -10,15 +10,18 @@ ALTER TABLE "cc_files" ADD CONSTRAINT "cc_files_track_type_fkey"
     FOREIGN KEY ("track_type_id")
     REFERENCES "cc_track_types" ("id");
 
-UPDATE "cc_files" previous SET "track_type_id" = (
+UPDATE "cc_files" SET "track_type" = NULL
+WHERE "track_type" = '';
+
+UPDATE "cc_files" file SET "track_type_id" = (
     SELECT "id" FROM "cc_track_types"
-    WHERE "code" = previous."track_type"
+    WHERE "code" = file."track_type"
 )
 WHERE "track_type" IS NOT NULL;
 
-UPDATE "cc_pref" previous SET "valstr" = (
+UPDATE "cc_pref" file SET "valstr" = (
     SELECT "id" FROM "cc_track_types"
-    WHERE "code" = previous."valstr"
+    WHERE "code" = file."valstr"
 )
 WHERE "keystr" = 'tracktype_default'
 AND "valstr" <> '';
@@ -27,17 +30,23 @@ ALTER TABLE "cc_files" DROP COLUMN IF EXISTS "track_type";
 """
 
 DOWN = """
-ALTER TABLE "cc_files" DROP CONSTRAINT "cc_files_track_type_fkey";
-ALTER TABLE "cc_files" DROP COLUMN IF EXISTS "track_type_id";
-
 ALTER TABLE "cc_files" ADD COLUMN "track_type" VARCHAR(16);
 
-UPDATE "cc_pref" previous SET "valstr" = (
+UPDATE "cc_files" file SET "track_type" = (
     SELECT "code" FROM "cc_track_types"
-    WHERE "id" = previous."valstr"::int
+    WHERE "id" = file."track_type_id"
+)
+WHERE "track_type_id" IS NOT NULL;
+
+UPDATE "cc_pref" pref SET "valstr" = (
+    SELECT "code" FROM "cc_track_types"
+    WHERE "id" = pref."valstr"::int
 )
 WHERE "keystr" = 'tracktype_default'
 AND "valstr" <> '';
+
+ALTER TABLE "cc_files" DROP CONSTRAINT "cc_files_track_type_fkey";
+ALTER TABLE "cc_files" DROP COLUMN IF EXISTS "track_type_id";
 """
 
 
diff --git a/docs/releases/unreleased.md b/docs/releases/unreleased.md
index 1eadd34b3..bc203db11 100644
--- a/docs/releases/unreleased.md
+++ b/docs/releases/unreleased.md
@@ -33,13 +33,15 @@ Please run this **before the upgrade procedure**!
 The database files track type field was previously not constrained and this might have lead to files referencing a now renamed or missing track type. To preserve as much data as possible during the database migration process, you need to check whether some files have broken or missing track type references and fix them accordingly. To list broken track type references, you can run the following command:
 
 ```bash
-sudo -u www-data libretime-api dbshell --command="
+sudo -u libretime libretime-api dbshell --command="
     SELECT f.id, f.track_type, f.track_title, f.artist_name, f.filepath
     FROM cc_files f
     WHERE NOT EXISTS (
         SELECT FROM cc_track_types tt
         WHERE tt.code = f.track_type
-    );"
+    )
+    AND f.track_type IS NOT NULL
+    AND f.track_type <> '';"
 ```
 
 If the above command outputs the following, no file needs fixing.