Question

所以我有一个ID列表，后来用一个字符串来描述这个问题。

我希望通过ID过滤掉这些内容，并根据主要ID＃

显示字符串

select
sol.solution `Solution`,
count(sol.id) `Solution Count`,
case sol.id when 8,9,10,11,12,13,14,15,16,25,29,33,37,40,41,42,48,51 then 'Hardware'
else 'Software' end `HW/SW`
from tickets t
   join ticket_solutions tsol
    on tsol.ticket_id =t.id
   join solutions sol
    on tsol.solution_id = sol.id

Answer 1

由于您的描述不是100％明确，因此我只是猜测：

SELECT
sol.solution `Solution`,
COUNT(t.id) `Solution Count`,
IF(sol.id IN (8,9,10,11,12,13,14,15,16,25,29,33,37,40,41,42,48,51),'Hardware','Software') `HW_SW`
FROM tickets t
JOIN ticket_solutions tsol
  ON tsol.ticket_id =t.id
JOIN solutions sol
  ON tsol.solution_id = sol.id
GROUP BY sol.id

Answer 2

缩短形式的case表达式不会采用值列表，只会采用单个值。但是，您可以使用带有in运算符的较长（基于条件的）表单：

CASE WHEN sol.id IN (8,9,10,11,12,13,14,15,16,25,29,33,37,40,41,42,48,51)  
     THEN 'Hardware'
     ELSE 'Software'
END AS `HW/SW`

我试图根据列表中的值返回一个字符串

2 个答案: