Question

I have a table that records all user cross-profile visits and I need to get the count of distinct visits and the count of new visits to a specified profile (:user_id) since the specified UNIX timestamp (:time).

id  | user_id  | visitor_id |  time (unix)
====+==========+============+=============
  1 |     1    |       5    |  1300000000
  2 |     1    |       5    |  1300000010
  3 |     1    |       8    |  1300000015
  4 |     1    |       9    |  1300000020
  5 |     1    |       9    |  1300000025
  6 |     1    |       9    |  1300000030

So far I was only able to get the count of total visits, but am unable to get the new ones.

SELECT COUNT(DISTINCT v.visitor_id) AS total, SUM(v.time > 1300000012) AS new FROM profile_visits v WHERE v.user_id = 1

returns

total | new
============
   3  |   4

but the required result is

total | new
============
   3  |   2

Answer 1

You probably want SUM(v.time > 1300000012) AS new.

The expression is either 0 or 1. COUNT() will count 0 as happily as 1. But SUM() will “count” only the 1’s.

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Re your comment:

SELECT COUNT(t.visitor_id) AS total, SUM(t.subtotal_new) AS total_new
FROM (SELECT v.visitor_id, SUM(v.time > 1300000012) AS subtotal_new
  FROM profile_visits AS v GROUP BY v.visitor_id) AS t

The SUM() of the inner query counts new visits per visitor. The SUM() of the outer query gives the total new visits for all visitors.