greatest-n-per-group

It's hard to show my actual table and data here so I'll describe my problem with a sample table and data: create table foo(id int,x_part int,y_part int,out_id int,out_idx text); insert into foo values (1,2,3,55,'BAK'),(2,3,4,77,'ZAK'),(3,4,8,55,'RGT'),(9,10,15,77,'UIT'), (3,4,8,11,'UTL'),(3,4,8,65,'MAQ'),(3,4,8,77,'YTU'); Following is the table foo : id x_part y_part out_id out_idx -- ------ ------ ------ ------- 3 4 8 11 UTL 3 4 8 55 RGT 1 2 3 55 BAK 3 4 8 65 MAQ 9 10 15 77 UIT 2 3 4 77 ZAK 3 4 8 77 YTU I need to select all fields by sorting the highest id of each out_id . Expected output: id

Let's say I have a table: Name, status, timestamp And I want to select the rows that match status='active' but only those that have the most recent timestamp for each of them. So if there were rows like this: Bob, active, 5/10/2010 Bob, active, 6/12/2010 Ann, inactive, 6/12/2000 Ann, active, 9/3/2009 Ann, active, 9/25/2010 I'd want it to return: Bob, active, 6/12/2010 Ann, active, 9/25/2010 How can I do this? I'm using SQLite, if it matters. Thank you. select name, status, max(timestamp) from my_table where status = 'active' group by name, status take a look at http://www.w3schools.com/sql/sql

I have two tables players and scores . I want to generate a report that looks something like this: player first score points foo 2010-05-20 19 bar 2010-04-15 29 baz 2010-02-04 13 Right now, my query looks something like this: select p.name player, min(s.date) first_score, s.points points from players p join scores s on s.player_id = p.id group by p.name, s.points I need the s.points that is associated with the row that min(s.date) returns. Is that happening with this query? That is, how can I be certain I'm getting the correct s.points value for the joined row? Side note: I imagine this is

I checked other solutions to similar problems, but sqlite does not support row_number() and rank() functions or there are no examples which involve joining multiple tables, grouping them by multiple columns and returning only top N results for each group at the same time. Here's the code i run db = sqlite3.connect('mydb') cursor = db.cursor() cursor.execute( ''' CREATE TABLE orders( id INTEGER PRIMARY KEY, product_id INTEGER, client_id INTEGER ) ''' ) cursor.execute( ''' CREATE TABLE clients( id INTEGER PRIMARY KEY, gender TEXT, city TEXT ) ''' ) cursor.execute( ''' CREATE TABLE products( id

With table table1 like below +--------+-------+-------+------------+-------+ | flight | orig | dest | passenger | bags | +--------+-------+-------+------------+-------+ | 1111 | sfo | chi | david | 3 | | 1112 | sfo | dal | david | 7 | | 1112 | sfo | dal | kim | 10| | 1113 | lax | san | ameera | 5 | | 1114 | lax | lfr | tim | 6 | | 1114 | lax | lfr | jake | 8 | +--------+-------+-------+------------+-------+ I'm aggregating the table by orig like below select orig , count(*) flight_cnt , count(distinct passenger) as pass_cnt , percentile_cont(0.5) within group ( order by bags ASC) as bag_cnt

The following query selects all posts and each post's owner, all of the comments that belong to each post, and the owner of each comment. I need to only retrieve 5 comments per post. I rewrote the query, but I get an error of "each derived table must have it's own alias". SELECT posts.id AS postId, posts.body, users.id AS userId, users.displayname, comments.id AS commentId, comments.text, commenters.id, commenters.displayname FROM posts JOIN users ON posts.owneruserid = users.id LEFT JOIN comments ON posts.id = comments.postid JOIN users AS commenters ON comments.userId = commenters.id ORDER