如何基于另一列的值SQL在查询中选择创建/添加列？
我想hook_name根据条件通过SQL选择查询动态添加另一列。例如，如果hook_type = 0，表hook_name的值应为OFFER，对于hook_type =1，类似的表hook_name应显示“ ACCEPT”。
以下是屏幕截图的结果：
https://i.stack.imgur.com/qfJsr.png
查询的选择如下：
select hook_type,'hook name' as hook_name, count(*) as number_of_exchange_activities from `exchange` group by hook_type # hook_type 0 for OFFER,1 for ACCEPT and 2 for offer EXPIRED;提前致谢。
解决方案:
使用标准的SQL CASE：
SELECT hook_type, CASE hook_type WHEN 0 THEN 'OFFER WHEN 1 THEN 'ACCEPT WHEN 2 THEN 'EXPIRED' END AS hook_name,COUNT(*) AS number_of_exchange_activities FROM `exchange` GROUP BY hook_type
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