Fixed indexes in the categories table.

database/2019_04_10_093908_fix_forum_indices.php

@@ -0,0 +1,26 @@
+<?php
+namespace Misuzu\DatabaseMigrations\FixForumIndices;
+
+use PDO;
+
+function migrate_up(PDO $conn): void
+{
+    $conn->exec("
+        ALTER TABLE `msz_forum_categories`
+            DROP INDEX `forums_indices`,
+            ADD INDEX `forum_order_index` (`forum_order`),
+            ADD INDEX `forum_parent_index` (`forum_parent`),
+            ADD INDEX `forum_type_index` (`forum_type`);
+    ");
+}
+
+function migrate_down(PDO $conn): void
+{
+    $conn->exec("
+        ALTER TABLE `msz_forum_categories`
+            DROP INDEX `forum_order_index`,
+            DROP INDEX `forum_parent_index`,
+            DROP INDEX `forum_type_index`,
+            ADD INDEX `forums_indices` (`forum_order`, `forum_parent`, `forum_type`);
+    ");
+}