如何在mysql中使用同一张表获取零的计数值？

Question

这是MySql这句话

select if(b.opcionselec='Y','Yes','No') as opt, count(b.idPregunta) as val
from respuestabuleanas as b where b.idPregunta='1' group by (b.opcionselec);

查询结果

 opt           val
 No             1

我想得到什么

 opt           val
 No             1
 Yes            0

有什么方法可以实现吗？

Answer 1

select if(b.opcionselec='Y','Yes','No') as opt, count(b.idPregunta) as val
from respuestabuleanas as b 

LEFT JOIN respuestabuleanas as b1 ON b1.idPregunta='1' group by (b.opcionselec);

Answer 2

select if(b.opcionselec='Y','Yes','No') as opt, count(b.idPregunta) as val = 
      CASE opt
         WHEN 'YES' THEN '0'
       END,
from respuestabuleanas as b 

LEFT JOIN respuestabuleanas as b1 ON b1.idPregunta='1' group by (b.opcionselec);