select  *
from product
where purchase_price@H_403_16@>500

union

select @H_403_16@ product2
500;

-- 内连结
FROM @H_403_16@<tb_1@H_403_16@> INNER @H_403_16@JOIN @H_403_16@<tb_2@H_403_16@ON @H_403_16@<condition(s)@H_403_16@>

SELECT  SP.shop_id,SP.shop_name,SP.product_id,P.product_name,P.product_type,P.sale_price,SP.quantity
  FROM shopproduct AS SP
 JOIN product  P
    ON SP.product_id @H_403_16@= P.product_id
 WHERE SP.shop_name @H_403_16@= '东京'
   @H_403_16@AND P.product_type @H_403_16@衣服' ;