mysql - 如何在查询中仅乘以一行？

Question

SELECT user_id, currency, SUM( price ) AS totalPrice, created
FROM accounts WHERE user_id IN ( SELECT users.id FROM users
                                 WHERE country_id ='$con_id' )
AND created BETWEEN  '2013-02-01' AND  '2013-02-28' GROUP BY currency

这个查询给我的结果如下

Curreny  totalPrice
SEK      10
USD      10

我只想从 7 乘以 SEK。数据库中只有 USD 汇率，因此我想在查询中将其与 7 获取瑞典克朗汇率。我怎样才能在这个查询中做到这一点？

Answer 1

你的问题有点令人困惑。如果我正确理解您的问题，如果货币等于 SEK，您希望将总值(value)乘以 7。

SELECT  user_id, 
        currency, 
        SUM(price) * IF(currency = 'SEK', 7, 1) totalPrice, 
        created
FROM    accounts
WHERE   user_id
        IN 
        (
            SELECT users.id
            FROM users
            WHERE country_id =  '$con_id'
        ) AND 
        created BETWEEN  '2013-02-01' AND  '2013-02-28'
GROUP   BY currency