aggregation

I have a mysql table like: id, visitorid, pageid When a visitor hits the website it stores their visitor id and the page id as a row. I am trying to extract the number of visitors who hit the website exactly X times. (for a chart). so how many visit just one page, how many visit 2 pages... so far I have: SELECT COUNT(visid),visid FROM vislog GROUP BY visid ORDER BY COUNT(visid) DESC But I don't know how to do the next part of counting the counts. Is it possible to do as a mysql query? Edit: I have added my answer . You can wrap your query inside another one: SELECT cnt AS page_visits , COUNT(*

I encountered a problem that elasticsearch could not return the count of unique documents by just using terms aggregation on a nested field. Here is an example of our model: { ..., "location" : [ {"city" : "new york", "state" : "ny"}, {"city" : "woodbury", "state" : "ny"}, ... ], ... } I want to do aggregation on the state field, but this document will be counted twice in the 'ny' bucket since 'ny' appears twice in the document. So I'm wondering if where is a way to grab the count of distinct documents. mapping: people = { :properties => { :location => { :type => 'nested', :properties => {

My aggregation needs vary among columns / data.frames. I would like to pass the "list" argument to the data.table dynamically. As a minimal example: require(data.table) type <- c(rep("hello", 3), rep("bye", 3), rep("ok",3)) a <- (rep(1:3, 3)) b <- runif(9) c <- runif(9) df <- data.frame(cbind(type, a, b, c), stringsAsFactors=F) DT <-data.table(df) This call: DT[, list(suma = sum(as.numeric(a)), meanb = mean(as.numeric(b)), minc = min(as.numeric(c))), by= type] will have result similar to this: type suma meanb minc 1: hello 6 0.1332210 0.4265579 2: bye 6 0.5680839 0.2993667 3: ok 6 0.5694532 0

I have below table create table #t (Id int, Name char) insert into #t values (1, 'A'), (2, 'A'), (3, 'B'), (4, 'B'), (5, 'B'), (6, 'B'), (7, 'C'), (8, 'B'), (9, 'B') I want to count consecutive values in name column +------+------------+ | Name | Repetition | +------+------------+ | A | 2 | | B | 4 | | C | 1 | | B | 2 | +------+------------+ The best thing I tried is: select Name , COUNT(*) over (partition by Name order by Id) AS Repetition from #t order by Id but it doesn't give me expected result One approach is the difference of row numbers: select name, count(*) from (select t.*, (row