fix products listing

i18n/migrations/20260302163122_create_tables.sql

@@ -200,6 +200,35 @@ END //
 
 DELIMITER ;
 
+
+DELIMITER $$
+
+CREATE FUNCTION IF NOT EXISTS get_subcategories(startCategory INT)
+RETURNS TEXT
+DETERMINISTIC
+BEGIN
+    DECLARE result TEXT;
+
+    -- Use GROUP_CONCAT to aggregate all IDs into a single string
+    WITH RECURSIVE subcategories AS (
+        SELECT c.id_category
+        FROM ps_category c
+        WHERE c.id_category = startCategory
+
+        UNION ALL
+
+        SELECT c.id_category
+        FROM ps_category c
+        INNER JOIN subcategories sc ON c.id_parent = sc.id_category
+    )
+    SELECT GROUP_CONCAT(id_category) INTO result
+    FROM subcategories;
+
+    RETURN result;
+END$$
+
+DELIMITER ;
+
 -- +goose Down
 
 DROP TABLE IF EXISTS b2b_countries;