如何 select 从表和整个其他表的一列中区分值？

Question

 SELECT  (DISTINCT visits.user_id), purchases FROM visits

Trying to do smth like this but it is not working.

Answer 1

Use aggregation. Perhaps:

SELECT v.user_id, ANY_VALUE(purchases)
FROM visits v
GROUP BY v.user_id;

Or, if you want the total number of purchases -- assuming purchases is a number:

SELECT v.user_id, SUM(purchases)
FROM visits v
GROUP BY v.user_id;