greatest-n-per-group

I have the following table. test_type | brand | model | band | firmware_version | avg_throughput -----------+---------+--------+------+-----------------+---------------- 1client | Linksys | N600 | 5ghz | 1 | 66.94 1client | Linksys | N600 | 5ghz | 2 | 94.98 1client | Linksys | N600 | 5ghz | 4 | 132.40 1client | Linksys | EA6500 | 5ghz | 1 | 216.46 1client | Linksys | EA6500 | 5ghz | 2 | 176.79 1client | Linksys | EA6500 | 5ghz | 4 | 191.44 I'd like to select the avg_throughput of each model that has the lowest firmware_version . When I do SELECT test_type, model, min(firmware_version) FORM

Lets say I have a database table called "Scrape" possibly setup like: UserID (int) UserName (varchar) Wins (int) Losses (int) ScrapeDate (datetime) I'm trying to be able to rank my users based on their Wins/Loss ratio. However, each week I'll be scraping for new data on the users and making another entry in the Scrape table. How can I query a list of users sorted by wins/losses, but only taking into consideration the most recent entry (ScrapeDate)? Also, do you think it matters that people will be hitting the site and the scrape may possibly be in the middle of completing? For example I could

I know the title does not sound very descriptive, but it is the best I could think of: I have this table ID BDATE VALUE 28911 14/4/2009 44820 28911 17/4/2009 32240 28911 20/4/2009 30550 28911 22/4/2009 4422587,5 28911 23/4/2009 4441659 28911 24/4/2009 7749594,67 38537 17/4/2009 58280 38537 20/4/2009 137240 38537 22/4/2009 81098692 38605 14/4/2009 2722368 38605 20/4/2009 5600 38605 22/4/2009 1625400 38605 23/4/2009 6936575 which is in fact a very complicated query encapsulated in a view, but it is not of the matter now. I would like to have for each ID, the row containing the highest BDate. In

Table: | id | productId | orderIndex | rejected | ------------------------------------------ | 1 | 1 | 0 | 1 | | 2 | 1 | 1 | 0 | | 3 | 1 | 2 | 0 | | 4 | 2 | 0 | 0 | | 5 | 2 | 1 | 1 | | 6 | 3 | 0 | 0 | How can I select one row per productId with minimum orderIndex that not rejected? Expected result: | id | productId | orderIndex | rejected | ------------------------------------------ | 2 | 1 | 1 | 0 | | 4 | 2 | 0 | 0 | | 6 | 3 | 0 | 0 | I tried this query, but don't recieved correct result: SELECT id, productId, min(orderIndex) FROM table WHERE rejected = 0 GROUP BY productId This one don't

I currently have the following table: ID | Name | EventTime | State 1001 | User 1 | 2013/07/22 00:00:05 | 15 1002 | User 2 | 2013/07/23 00:10:00 | 100 1003 | User 3 | 2013/07/23 06:15:31 | 35 1001 | User 1 | 2013/07/23 07:13:00 | 21 1001 | User 1 | 2013/07/23 08:15:00 | 25 1003 | User 3 | 2013/07/23 10:00:00 | 22 1002 | User 2 | 2013/07/23 09:18:21 | 50 What I need is the state for each distinct userid from the last eventtime similar to below: ID | Name | EventTime | State 1001 | User 1 | 2013/07/23 08:15:00 | 25 1003 | User 3 | 2013/07/23 10:00:00 | 22 1002 | User 2 | 2013/07/23 09:18:21 | 50

I've done research on this problem, but am having trouble finding a solution. I have the following query that gives me a list of "some_id"s: SELECT some_id FROM example GROUP BY some_id And I have the following query that will get a list of the 5 most recent entries for a row that has "some_id" equal to a number. SELECT * FROM example WHERE some_id = 1 ORDER BY last_modified DESC LIMIT 5 How can I get the the top 5 most recent entries from the table "example" for each "some_id", using only one query? If there are less than 5 entries for a "some_id", it is okay to include them, if that makes

I am trying to get the latest 1 or 2 comments related to each post I download, a bit like instagram does as they show the latest 3 comments for each post, So far I am getting the posts & the likes counts. Now all I need to do is figure out how to get the latest comments, not too sure how to approach it and that is why I hoping someone with a lot more expertise can help me! This is my current query: (SELECT P.uuid, P.caption, P.imageHeight, P.path, P.date, U.id, U.fullname, U.coverImage, U.bio, U.username, U.profileImage, coalesce(Activity.LikeCNT,0), Activity.CurrentUserLiked FROM USERS AS U