UNION cannot combine two results with the same column

Question

Enter image description here I'm trying to combine these two queries in the same display result, but the Mysql system keeps saying that UNION cannot be at this location. If union doesn't work, how can I combine these two queries?

P粉329425839 · Answer

https://dev.mysql.com/doc/refman /8.0/en/union.html said:

In your case it would look like this:

(select customer_id, points, state from customers where state = 'CA' order by points desc limit 3)
union
(select customer_id, points, state from customers where state = 'FL' order by points desc limit 3)

You may also want to knowWindow functions一个>:

select customer_id, points, state
from (
  select customer_id, points, state, 
    row_number() over (partition by state order by points desc) as rownum
  from customers where state in ('CA','FL')
) as t
where rownum