级联查询找不到列

因为没有创建连接

var select = ctx
        .select(PRODUCT.NAME, PRODUCT.CODE, BRAND.NAME.as("brandName"), CATEGORY.NAME.as("categoryName"))
        .from(PRODUCT)
        .leftJoin(BRAND).on(PRODUCT.BRAND_ID.eq(BRAND.ID))
        .leftJoin(CATEGORY).on(PRODUCT.CATEGORY_ID.eq(CATEGORY.ID))
        .where(condition);