Clean up sizes/sizegroup: deduplicate sizes + cross-reference table

db/migrations/20260421120000_create_sizes_sizegroup_table.php

@@ -0,0 +1,86 @@
+<?php
+
+declare(strict_types=1);
+
+use Phinx\Migration\AbstractMigration;
+
+/**
+ * Creates the sizes_sizegroup cross-reference table that stores the many-to-many
+ * relationship between sizes and sizegroups, then drops the now-redundant
+ * sizegroup_id and seq columns from the sizes table.
+ *
+ * This migration runs BEFORE DeduplicateSizes so that every size – including
+ * the duplicates that will later be removed – already has a row in
+ * sizes_sizegroup before deduplication happens. When DeduplicateSizes removes
+ * duplicate rows from sizes, the corresponding sizes_sizegroup rows are removed
+ * automatically via the size_id foreign key's ON DELETE CASCADE behavior.
+ */
+final class CreateSizesSizegroupTable extends AbstractMigration
+{
+    public function up(): void
+    {
+        // ----------------------------------------------------------------
+        // 1. Create cross-reference table
+        // ----------------------------------------------------------------
+        $this->execute('CREATE TABLE `sizes_sizegroup` (
+            `size_id`      INT UNSIGNED NOT NULL,
+            `sizegroup_id` INT UNSIGNED NOT NULL,
+            `seq`          INT          DEFAULT NULL,
+            PRIMARY KEY (`size_id`, `sizegroup_id`),
+            KEY `idx_sizegroup_id` (`sizegroup_id`),
+            CONSTRAINT `fk_ss_size_id`
+                FOREIGN KEY (`size_id`)      REFERENCES `sizes`     (`id`)
+                ON DELETE CASCADE ON UPDATE CASCADE,
+            CONSTRAINT `fk_ss_sizegroup_id`
+                FOREIGN KEY (`sizegroup_id`) REFERENCES `sizegroup` (`id`)
+                ON DELETE CASCADE ON UPDATE CASCADE
+        ) ENGINE=InnoDB DEFAULT CHARSET=utf8 ROW_FORMAT=DYNAMIC');
+
+        // ----------------------------------------------------------------
+        // 2. Populate from existing sizes.sizegroup_id (one row per size,
+        //    including rows for the duplicates that DeduplicateSizes will
+        //    later remove along with their sizes_sizegroup entries)
+        // ----------------------------------------------------------------
+        $this->execute('INSERT INTO `sizes_sizegroup` (`size_id`, `sizegroup_id`, `seq`)
+            SELECT `id`, `sizegroup_id`, `seq`
+            FROM   `sizes`
+            WHERE  `sizegroup_id` IS NOT NULL');
+
+        // ----------------------------------------------------------------
+        // 3. Drop the now-redundant columns from sizes
+        // ----------------------------------------------------------------
+        $this->table('sizes')->dropForeignKey('sizegroup_id')->save();
+        $this->table('sizes')->removeColumn('sizegroup_id')->save();
+        $this->table('sizes')->removeColumn('seq')->save();
+    }
+
+    public function down(): void
+    {
+        // Restore sizegroup_id and seq columns on sizes
+        $this->execute('ALTER TABLE `sizes`
+            ADD COLUMN `sizegroup_id` INT UNSIGNED DEFAULT NULL AFTER `label`,
+            ADD COLUMN `seq`          INT          DEFAULT NULL AFTER `sizegroup_id`,
+            ADD KEY    `sizegroup_id` (`sizegroup_id`),
+            ADD CONSTRAINT `sizes_ibfk_4`
+                FOREIGN KEY (`sizegroup_id`) REFERENCES `sizegroup` (`id`)
+                ON UPDATE CASCADE');
+
+        // Re-populate from the cross-reference table.
+        // Where a size belongs to multiple sizegroups, pick the row with the
+        // smallest sizegroup_id as the "primary" one (mirrors the original data).
+        $this->execute('UPDATE `sizes` s
+            JOIN (
+                SELECT   size_id, sizegroup_id, seq
+                FROM     sizes_sizegroup ss1
+                WHERE    sizegroup_id = (
+                    SELECT MIN(sizegroup_id)
+                    FROM   sizes_sizegroup ss2
+                    WHERE  ss2.size_id = ss1.size_id
+                )
+            ) best ON best.size_id = s.id
+            SET s.sizegroup_id = best.sizegroup_id,
+                s.seq          = best.seq');
+
+        $this->execute('DROP TABLE `sizes_sizegroup`');
+    }
+}