如果您只想要 ayes
如果它是 1,并且每个其他值都会导致 a no
,您可以这样做:
select case
when MyColumn = 'yes' then 1
else 0
end as MyDerivedValue
from MyTable
或者,您可以更具体:
select case MyColumn
when 'yes' then 1
when 'no' then 0
when 'maybe' then 2
else -1
end as MyDerivedValue
from MyTable