Question

我试图根据活动预订制作一张桌子。人们预定自己参加活动，并指定他们将携带多少客人。

我希望表格中的每一行分别列在列中：预订，此人携带的客人人数，以及预订+客人的总和（实际上，此第三列将为否客人+1）。

SELECT 'Open day' Event,
       CASE WHEN BOOKINGSTATUS = 'Booked' THEN 1 ELSE 0 END as 'Current Bookings',
       GUESTS as 'Number of Guests',
       SUM ('Current Bookings'+'Number of Guests') as 'Total: Booking & Guests'
WHERE EVENTID = 'xxxxx-111111-22222-xxxxx'

我遇到的问题是＆＃39; 1＆＃39; “当前预订”中的价值＆＃39;列显然是VARCHAR。这是错误消息：

Msg 245，Level 16，State 1，Line 1

转换varchar值时，转化失败＆＃39;当前预订＆＃39;   数据类型int。

如何将此转换为CASE语句中的整数，然后这会使最终列的总和为每行的总和？

感谢任何指导。

Answer 1

SUM是一个set函数，只需执行+即可在一行内求和。（但你不能在那里使用列别名。）

SELECT 'Open day' Event,
       CASE WHEN BOOKINGSTATUS = 'Booked' THEN 1 ELSE 0 END as 'Current Bookings',
       GUESTS as 'Number of Guests',
       CASE WHEN BOOKINGSTATUS = 'Booked' THEN 1 ELSE 0 END + GUESTS as 'Total: Booking & Guests'
WHERE EVENTID = 'xxxxx-111111-22222-xxxxx'

Answer 2

请尝试

SELECT 
    'Open day' Event, 
    CASE WHEN BOOKINGSTATUS = 'Booked' THEN 1 ELSE 0 END as 'Current Bookings',
    GUESTS as 'Number of Guests',
    SUM ( CASE WHEN BOOKINGSTATUS = 'Booked' THEN 1 ELSE 0 END + GUESTS) as 'Total: Booking & Guests'
WHERE EVENTID = 'xxxxx-111111-22222-xxxxx'

如何将CASE varchar转换为INT，以便我可以在一行中求和？

2 个答案: