with t1 as(
    select case when course like '%course1%' then 1 else 0 end as c1,
           case when course like '%course2%' then 1 else 0 end as c2,
           case when course like '%course3%' then 1 else 0 end as c3
    from cultivate_tb
)
select sum(c1)+sum(c2)+sum(c3) as staff_nums
from t1