python - Return count of column based on previous data -
how can count user_id group type, country_code , date current type d or , previous type d or a. e.g query should return country_code 1 , type d => count(user_id) = 1 , country_code 2 , type => count(user_id) = 1 id country_code type user_id date 1 1 d 1 01-01-14 2 1 nd 1 02-01-14 3 1 d 1 03-01-14 4 1 d 1 04-01-14 5 2 d 1 05-01-14 6 2 nd 2 06-01-14 7 2 1 07-01-14 8 2 1 08-01-14 i think want following: select type, country_code, date, count(distinct user_id) tbl x type in ('d', 'a') , exists (select 1 tbl y y.type in ('d', 'a') , y.country_code = x.country_code , y.date <= (select max(z.date) tbl z z.date < x.date , z.type = y.type
