-- 回滚：删除订单过期时间索引和字段
DO $$
BEGIN
    -- 删除复合索引
    IF EXISTS (
        SELECT 1 FROM pg_indexes
        WHERE tablename='tb_order'
        AND indexname='idx_order_expires'
    ) THEN
        DROP INDEX idx_order_expires;
    END IF;

    -- 删除 expires_at 字段
    IF EXISTS (
        SELECT 1 FROM information_schema.columns
        WHERE table_name='tb_order'
        AND column_name='expires_at'
    ) THEN
        ALTER TABLE tb_order DROP COLUMN expires_at;
    END IF;
END
$$;