如何在mysql中使用相同的表获取零计数值？

Question

这是句子MySql

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

我想要的是什么

 opt           val
 No             1
 Yes            0

有没有办法实现它？

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);