如果一个字段等于 5 或 10，则不要将另一个字段相乘 - Don't multiply a field if another field equals 5 or 10

Don't multiply a field if another field equals 5 or 10

本文关键字：字段另一个一个如果 | 更新日期: 2023-09-27

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。价格单是通过简单地将票价翻倍来计算的。但是，对于某些行，该类别无论如何都是单程票价，所以我不想将其翻倍。该查询实际上嵌入在 PHP 的字符串中，但 SQL 如下所示：

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'

当category等于 5 或 10 时，如何避免执行fare*2？

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