通过分别在id列和product_id列上联接info和sell_info表，然后使用MIN（）函数获取最低价格，可以获得所需的结果。

SELECT info.id, info.name, MIN(sell_info.price) AS price
FROM info
JOIN sell_info ON info.id = sell_info.product_id
WHERE info.id = 1
GROUP BY info.id, info.name;

下面的查询将给予您想要的结果。
它使用内部查询从SELL_INFO表中获取每个产品ID的最低价格，然后使用该内部查询中的产品ID联接到INFO表，以获取产品的名称。

SELECT
  INFO.ID, 
  INFO.NAME,
  MINP.MIN_PRICE
FROM
  INFO as INFO
  INNER JOIN 
  (
  SELECT 
    SI.PRODUCT_ID as PRODUCT_ID, 
    min(SI.PRICE) as MIN_PRICE
  FROM
    SELL_INFO as SI
  GROUP BY
    SI.PRODUCT_ID
  ) as MINP
    ON INFO.ID = MINP.PRODUCT_ID
WHERE
MINP.PRODUCT_ID = 1

这个应该可以

SELECT i.id, i.name, MIN(s.price) as price
FROM info as i, sell_info as s
WHERE i.id = s.product_id AND i.id = 1
GROUP BY i.id, i.name

这很简单。这里有一个SQLFIDDLE。

select i.id, i.name, s.price
from info i
JOIN sell_info s ON i.id = s.product_id
WHERE i.id = 1 AND s.price = (
    SELECT MIN(price)
    FROM sell_info
    WHERE product_id = 1
);