php - 如果另一个字段等于 5 或​​ 10，则不要乘以一个字段

Question

我正在运行此查询，该查询正在填充我的临时表，然后从中导出。priceSingle 只需将票价加倍即可计算。但是，对于某些行，无论如何，类别都是单程票价，所以我不想加倍。查询实际上嵌入在 PHP 中的字符串中，但 SQL 看起来像：

INSERT INTO temp
    SELECT cruises.code AS sailingId, live, 'USD', 'optioncode', 'rateOptionName', '2',
           category AS cabinCategory, fare*2 AS priceSingle, fare AS priceDouble,
           supplements_usa.adult AS priceAdditional
      FROM fares_usa, supplements_usa, cruises
     WHERE fares_usa.cruise_id = supplements_usa.cruise_id
       AND cruises.id = fares_usa.cruise_id AND cruises.live = 'Y'

fare*2当category等于 5 或​​ 10时，我怎样才能避免这样做？

Answer 1

CASE WHEN category = 5 OR category = 10 THEN fare ELSE fare * 2 END