From 027b98ce76f28d8f6b7b28602c01dc93ebb58c59 Mon Sep 17 00:00:00 2001
From: rr- <mkurczew@gmail.com>
Date: Sun, 28 Jun 2015 10:24:40 +0200
Subject: [PATCH] Fixed dangling tags on MySQL after post removal

---
 src/Upgrades/Upgrade39.php | 22 ++++++++++++++++++++++
 src/di.php                 |  1 +
 2 files changed, 23 insertions(+)
 create mode 100644 src/Upgrades/Upgrade39.php

diff --git a/src/Upgrades/Upgrade39.php b/src/Upgrades/Upgrade39.php
new file mode 100644
index 00000000..5a4d3077
--- /dev/null
+++ b/src/Upgrades/Upgrade39.php
@@ -0,0 +1,22 @@
+<?php
+namespace Szurubooru\Upgrades;
+use Szurubooru\DatabaseConnection;
+
+class Upgrade39 implements IUpgrade
+{
+    public function run(DatabaseConnection $databaseConnection)
+    {
+        $pdo = $databaseConnection->getPDO();
+
+        $pdo->exec('DROP TRIGGER IF EXISTS postsDelete');
+
+        // this triger is needed due to cascade triggers not working in MySQL.
+        // (specifically, postTagsDelete won't get triggered.)
+        $pdo->exec('
+            CREATE TRIGGER postsDelete AFTER DELETE ON posts
+            FOR EACH ROW
+            BEGIN
+                UPDATE tags SET usages = (SELECT COUNT(1) FROM postTags WHERE tagId = tags.id);
+            END');
+    }
+}
diff --git a/src/di.php b/src/di.php
index ba7c9a29..c9f00a6a 100644
--- a/src/di.php
+++ b/src/di.php
@@ -55,6 +55,7 @@ return [
             $container->get(\Szurubooru\Upgrades\Upgrade36::class),
             $container->get(\Szurubooru\Upgrades\Upgrade37::class),
             $container->get(\Szurubooru\Upgrades\Upgrade38::class),
+            $container->get(\Szurubooru\Upgrades\Upgrade39::class),
         ];
     }),