aggregate-functions

We have a table with the following columns: SESSION_ID USER_ID CONNECT_TS -------------- --------------- --------------- 1 99 2013-01-01 2:23:33 2 101 2013-01-01 2:23:55 3 104 2013-01-01 2:24:41 4 101 2013-01-01 2:24:43 5 233 2013-01-01 2:25:01 We need to get a distinct count of users for each day and a count of "active users" which are defined as users that have used the application in the last 45 days. Here is what we have come up with, but I feel like there has to be a better way: select trunc(a.connect_ts) , count(distinct a.user_id) daily_users , count(distinct b.user_id) active_users

This could be incredibly simple by the documentation is quite on it. Is there a way to aggregate columns via multiplication operator in postgresql. I know i can do count(column) or sum(column), but is there a multiply(column) or product(column) function that i can use. If not, any ideas how to achieve it. I'm using postgres 9.1 regards, Hassan Sure, just define an aggregate over the base multiplication function. E.g. for bigint: CREATE AGGREGATE mul(bigint) ( SFUNC = int8mul, STYPE=bigint ); Example: regress=> SELECT mul(x) FROM generate_series(1,5) x; mul ----- 120 (1 row) See CREATE

Why am I getting this error in my chart? ( Chart Image ) I am using this expression in the chart: Series: =Sum(Fields!Mins_Att.Value)/Sum(Fields!Mins_Poss.Value) Series 1: =Sum(Fields!Mins_Att.Value, "Chart2_CategoryGroup2")/Sum(Fields!Mins_Poss.Value, "Chart2_CategoryGroup2") and I am getting this error: The Y expression for the Chart has a scope parameter that is not valid for an aggregate function. The scope parameter must be set to a string constant that is equal the name of group, data region or name of dataset. The scope of "Chart2_CategoryGroup2" doesn't exist in the report. 来源： https:/

I have a MySQL table like the following: date count 2010-01-01 5 2010-01-02 6 2010-01-03 7 How can I accumulate the sum of each day to the next one? So the result is like: date acum per day 2010-01-01 5 2010-01-02 11 2010-01-03 18 I think i need some kind of for(each date)... but no clue. Just the final query i used following answer from Eric. (thanks). SELECT t1.dia, sum(t2.operacions), sum(t2.amount) FROM (SELECT count(*) operations, sum(amount), date(b.timestamp) dia FROM transactions b group by date(b.timestamp)) t1 INNER JOIN (SELECT count(*) operations, sum(amount), date(b.timestamp) dia

I am doing a query to get the number of builds per day from our database for the last 30 days. But it has become needed to marked days where there were no builds also. In my WHERE clause I use submittime to determine whether there were builds, how could I modify this to include days that have COUNT(id) == 0 but only in the last 30 days. Original Query: SELECT COUNT(id) AS 'Past-Month-Builds', CONCAT(MONTH(submittime), '-', DAY(submittime)) as 'Month-Day' FROM builds WHERE DATE(submittime) >= DATE_SUB(CURDATE(), INTERVAL 30 day) GROUP BY MONTH(submittime), DAY(submittime); What I've Tried:

I have a table data_summaries . It has such columns as item_id INT(11) , user_grouping TEXT and value DECIMAL(10,2) . If I try to make a query that groups the results by user_grouping and orders them by the AVG of value , that fails: SELECT user_grouping, AVG(value) AS avg_value, SUM(value) AS sum_value FROM data_summaries GROUP BY user_grouping ORDER BY avg_value +---------------+-----------+-----------+ | user_grouping | avg_value | sum_value | +---------------+-----------+-----------+ | London | 50.609733 | 18978.65 | | Paris | 50.791733 | 19046.90 | | New York | 51.500400 | 2575.02 | |