I'm new to this forum and I hope to find my solution about my problem.
I have this table :
name time points car date
Daniel | 55s | 210 | red |20/01/2018
Daniel | 45s | 250 | green |21/01/2018
Julie | 54s | 220 | red |19/01/2018
Julie | 33s | 150 | yellow|22/01/2018
and I wish to sort it like this
name time points car date
Daniel | 45s | 250 |green |21/01/2018
Julie | 54s | 220 |red |19/01/2018
first sorting by points, than sorting by time and group by name (optional the count)
I use this
SELECT NAME, MAX(POINTS) POINTS, MAX(TIME) TIME, MAX(CAR) CAR, MAX(DATE) DATE
FROM ( SELECT A.* FROM test A LEFT OUTER JOIN test B ON A.NAME=B.NAME AND
A.POINTS<B.POINTS AND A.TIME>B.TIME WHERE B.NAME IS NULL ) as sub GROUP BY NAME
and I get this :
name POINTS TIME CAR DATE
Daniel 250 45 green 2018-01-21
Julie 220 54 yellow 2018-01-22
Julie should have car=red & 2018-01-19
For Daniel it looks good
how can I get thise values (car & date) ?
thanks
Nico
You could give this a shot. It contains the table against itself and gets only records with the highest points and lowest time.
SELECT NAME, MAX(POINTS) POINTS, MAX(TIME) TIME
FROM
(
SELECT A.* FROM test A
LEFT OUTER JOIN test B ON A.NAME=B.NAME AND A.POINTS<B.POINTS AND A.TIME>B.TIME
WHERE B.NAME IS NULL
) GROUP BY NAME
For additional, try this:
SELECT * FROM
(
SELECT OUTERTEST.*,
#row_num := IF(#prev_value=OUTERTEST.name,#row_num+1,1) AS RowNumber,
#prev_value := OUTERTEST.name
FROM (SELECT * FROM TEST ORDER BY NAME, TEST.POINTS DESC, TEST.TIME ASC) OUTERTEST, (SELECT #row_num := 1, #prev_value := '') x
) A
WHERE A.ROWNUMBER=1
I did more test with this table
id name time points
1 Daniel 55 1140
2 Judie 54 1144
3 Judie 33 1028
4 Daniel 45 1180
5 Judie 53 1148
I apply this request
SELECT NAME, MAX(POINTS) POINTS, sub.TIME FROM (SELECT * FROM Testpoint ORDER BY POINTS DESC, TIME ASC) AS sub
GROUP BY sub.name
I have the max point for each name but the time is not the right one
name POINTS time
Daniel 1180 55
Judie 1148 54
Judie should have 53 for time and not 54
What I did wrong?
thankyou
Nico
Related
I am using PostgreSQL and I am trying to calculate the percentage change for two values in the same column and group them by the name column and I am having trouble.
Suppose I have the following table:
name
day
score
Allen
1
87
Allen
2
89
Allen
3
95
Bob
1
64
Bob
2
68
Bob
3
75
Carl
1
71
Carl
2
77
Carl
3
80
I want the result to be the name and the percentage change for each person between day 3 and day 1. So Allen would be 9.2 because from 87 to 95 is a 9.2 percent increase.
I want the result to be:
name
percent_change
Allen
9.2
Bob
17.2
Carl
12.7
Thanks for your help.
Try this...
with dummy_table as (
select
name,
day,
score as first_day_score,
lag(score, 2) over (partition by name order by day desc) as last_day_score
from YOUR_TABLE_NAME
)
select
name,
(last_day_score - first_day_score) / first_day_score::decimal as percentage_change
from dummy_table where last_day_score is not null
Just replace YOUR_TABLE_NAME. There are likely more performant and fancier solutions, but this works.
You can try with lag function, something like this:
select name, day, score, 100*(score - lag(score, 1) over (partition by name order by day))/(lag(score, 1) over (partition by name order by day)) as growth_percentage
Suppose I have the following SQL Table:
id | score
------------
1 | 4433
1 | 678
1 | 1230
1 | 414
5 | 8899
5 | 123
6 | 2345
6 | 567
6 | 2323
Now I wanted to do a GROUP BY id operation wherein the score column would be modified as follows: take the absolute difference between the top two highest scores for each id.
For example, the response for the above query should be:
id | score
------------
1 | 3203
5 | 8776
6 | 22
How can I perform this query in PostgreSQL?
Using ROW_NUMBER along with pivoting logic we can try:
WITH cte AS (
SELECT *, ROW_NUMBER() OVER (PARTITION BY id ORDER BY score DESC) rn
FROM yourTable
)
SELECT id,
ABS(MAX(score) FILTER (WHERE rn = 1) -
MAX(score) FILTER (WHERE rn = 2)) AS score
FROM cte
GROUP BY id;
Demo
Within my PostgreSQL database, I have an id column that shows each unique lead that comes in. I also have a connected_lead_id column which shows whether accounts are related to each other (ie husband and wife, parents and children, group of friends, group of investors, etc).
When we count the number of ids created during a time period, we want to see the number of unique "groups" of connected_ids during a period. In other words, we wouldn't want to count both the husband and wife pair, we would only want to count one since they are truly one lead.
We want to be able to create a view that only has the "first" id based on the "created_at" date and then contains additional columns at the end for "connected_lead_id_1", "connected_lead_id_2", "connected_lead_id_3", etc.
We want to add in additional logic so that we take the "first" id's source, unless that is null, then take the "second" connected_lead_id's source unless that is null and so on. Finally, we want to take the earliest on_boarded_date from the connected_lead_id group.
id | created_at | connected_lead_id | on_boarded_date | source |
2 | 9/24/15 23:00 | 8 | |
4 | 9/25/15 23:00 | 7 | |event
7 | 9/26/15 23:00 | 4 | |
8 | 9/26/15 23:00 | 2 | |referral
11 | 9/26/15 23:00 | 336 | 7/1/17 |online
142 | 4/27/16 23:00 | 336 | |
336 | 7/4/16 23:00 | 11 | 9/20/18 |referral
End Goal:
id | created_at | on_boarded_date | source |
2 | 9/24/15 23:00 | | referral |
4 | 9/25/15 23:00 | | event |
11 | 9/26/15 23:00 | 7/1/17 | online |
Ideally, we would also have i number of extra columns at the end to show each connected_lead_id that is attached to the base id.
Thanks for the help!
Ok the best I can come up with at the moment is to first build maximal groups of related IDs, and then join back to your table of leads to get the rest of the data (See this SQL Fiddle for the setup, full queries and results).
To get the maximal groups you can use a recursive common table expression to first grow the groups, followed by a query to filter the CTE results down to just the maximal groups:
with recursive cte(grp) as (
select case when l.connected_lead_id is null then array[l.id]
else array[l.id, l.connected_lead_id]
end from leads l
union all
select grp || l.id
from leads l
join cte
on l.connected_lead_id = any(grp)
and not l.id = any(grp)
)
select * from cte c1
The CTE above outputs several similar groups as well as intermediary groups. The query predicate below prunes out the non maximal groups, and limits results to just one permutation of each possible group:
where not exists (select 1 from cte c2
where c1.grp && c2.grp
and ((not c1.grp #> c2.grp)
or (c2.grp < c1.grp
and c1.grp #> c2.grp
and c1.grp <# c2.grp)));
Results:
| grp |
|------------|
| 2,8 |
| 4,7 |
| 14 |
| 11,336,142 |
| 12,13 |
Next join the final query above back to your leads table and use window functions to get the remaining column values, along with the distinct operator to prune it down to the final result set:
with recursive cte(grp) as (
...
)
select distinct
first_value(l.id) over (partition by grp order by l.created_at) id
, first_value(l.created_at) over (partition by grp order by l.created_at) create_at
, first_value(l.on_boarded_date) over (partition by grp order by l.created_at) on_boarded_date
, first_value(l.source) over (partition by grp
order by case when l.source is null then 2 else 1 end
, l.created_at) source
, grp CONNECTED_IDS
from cte c1
join leads l
on l.id = any(grp)
where not exists (select 1 from cte c2
where c1.grp && c2.grp
and ((not c1.grp #> c2.grp)
or (c2.grp < c1.grp
and c1.grp #> c2.grp
and c1.grp <# c2.grp)));
Results:
| id | create_at | on_boarded_date | source | connected_ids |
|----|----------------------|-----------------|----------|---------------|
| 2 | 2015-09-24T23:00:00Z | (null) | referral | 2,8 |
| 4 | 2015-09-25T23:00:00Z | (null) | event | 4,7 |
| 11 | 2015-09-26T23:00:00Z | 2017-07-01 | online | 11,336,142 |
| 12 | 2015-09-26T23:00:00Z | 2017-07-01 | event | 12,13 |
| 14 | 2015-09-26T23:00:00Z | (null) | (null) | 14 |
demo:db<>fiddle
Main idea - sketch:
Looping through the ordered set. Get all ids, that haven't been seen before in any connected_lead_id (cli). These are your starting points for recursion.
The problem is your number 142 which hasn't been seen before but is in same group as 11 because of its cli. So it is would be better to get the clis of the unseen ids. With these values it's much simpler to calculate the ids of the groups later in the recursion part. Because of the loop a function/stored procedure is necessary.
The recursion part: First step is to get the ids of the starting clis. Calculating the first referring id by using the created_at timestamp. After that a simple tree recursion over the clis can be done.
1. The function:
CREATE OR REPLACE FUNCTION filter_groups() RETURNS int[] AS $$
DECLARE
_seen_values int[];
_new_values int[];
_temprow record;
BEGIN
FOR _temprow IN
-- 1:
SELECT array_agg(id ORDER BY created_at) as ids, connected_lead_id FROM groups GROUP BY connected_lead_id ORDER BY MIN(created_at)
LOOP
-- 2:
IF array_length(_seen_values, 1) IS NULL
OR (_temprow.ids || _temprow.connected_lead_id) && _seen_values = FALSE THEN
_new_values := _new_values || _temprow.connected_lead_id;
END IF;
_seen_values := _seen_values || _temprow.ids;
_seen_values := _seen_values || _temprow.connected_lead_id;
END LOOP;
RETURN _new_values;
END;
$$ LANGUAGE plpgsql;
Grouping all ids that refer to the same cli
Loop through the id arrays. If no element of the array was seen before, add the referred cli the output variable (_new_values). In both cases add the ids and the cli to the variable which stores all yet seen ids (_seen_values)
Give out the clis.
The result so far is {8, 7, 336} (which is equivalent to the ids {2,4,11,142}!)
2. The recursion:
-- 1:
WITH RECURSIVE start_points AS (
SELECT unnest(filter_groups()) as ids
),
filtered_groups AS (
-- 3:
SELECT DISTINCT
1 as depth, -- 3
first_value(id) OVER w as id, -- 4
ARRAY[(MIN(id) OVER w)] as visited, -- 5
MIN(created_at) OVER w as created_at,
connected_lead_id,
MIN(on_boarded_date) OVER w as on_boarded_date -- 6,
first_value(source) OVER w as source
FROM groups
WHERE connected_lead_id IN (SELECT ids FROM start_points)
-- 2:
WINDOW w AS (PARTITION BY connected_lead_id ORDER BY created_at)
UNION
SELECT
fg.depth + 1,
fg.id,
array_append(fg.visited, g.id), -- 8
LEAST(fg.created_at, g.created_at),
g.connected_lead_id,
LEAST(fg.on_boarded_date, g.on_boarded_date), -- 9
COALESCE(fg.source, g.source) -- 10
FROM groups g
JOIN filtered_groups fg
-- 7
ON fg.connected_lead_id = g.id AND NOT (g.id = ANY(visited))
)
SELECT DISTINCT ON (id) -- 11
id, created_at,on_boarded_date, source
FROM filtered_groups
ORDER BY id, depth DESC;
The WITH part gives out the results from the function. unnest() expands the id array into each row for each id.
Creating a window: The window function groups all values by their clis and orders the window by the created_at timestamp. In your example all values are in their own window excepting 11 and 142 which are grouped.
This is a help variable to get the latest rows later on.
first_value() gives the first value of the ordered window frame. Assuming 142 had a smaller created_at timestamp the result would have been 142. But it's 11 nevertheless.
A variable is needed to save which id has been visited yet. Without this information an infinite loop would be created: 2-8-2-8-2-8-2-8-...
The minimum date of the window is taken (same thing here: if 142 would have a smaller date than 11 this would be the result).
Now the starting query of the recursion is calculated. Following describes the recursion part:
Joining the table (the original function results) against the previous recursion result. The second condition is the stop of the infinite loop I mentioned above.
Appending the currently visited id into the visited variable.
If the current on_boarded_date is earlier it is taken.
COALESCE gives the first NOT NULL value. So the first NOT NULL source is safed throughout the whole recursion
After the recursion which gives a result of all recursion steps we want to filter out only the deepest visits of every starting id.
DISTINCT ON (id) gives out the row with the first occurence of an id. To get the last one, the whole set is descendingly ordered by the depth variable.
I have 3 columns. SSN|AccountNumber|OpenDate
1 SSN may have multiple AccountNumbers
Each AccountNumber has a corresponding OpenDate
In my list I have many SSN's, each containing several account numbers which may have been opened on different days.
I want the results of my query to be SSN|earlest OpenDate|AccountNumber that corresponds with the earliest opendate.
I'm dealing with about 200,000 records.
EDIT: First I did
select SSN, min(OpenDate), AcctNumber from Table Group By SSN, AccountNumber
but that didn't quite give me the correct data.
The raw data gives me something like this:
SSN | AcctNumber | OpenDate
---------------------------
10 101 Jan
10 102 Feb
10 103 Mar
Where I got 10, Jan, and AccNumber 102 which is not the account number that is associated with Jan OpenDate After looking at others, I found that the account number I got was just one of the account numbers associated with that SSN rather than the one that corresponds with the min(OpenDate)
WITH CTE AS ( SELECT SSN, AcctNumber, OpenDate, ROW_NUM() OVER (PARTITION BY SSN ORDER BY OpenDate DESC) AS RN ) SELECT SSN, AcctNumber, OpenDate FROM CTE WHERE RN=1;
If your table is like this:
SSN | AcctNumber | OpenDate
---------------------------
10 101 April
10 101 May
10 102 April
20 201 June
20 201 July
Do you want your query to return this?
SSN | AcctNumber | OpenDate
---------------------------
10 101 April
10 102 April
20 201 June
Then you would use this query:
select ssn, min(OpenDate), acctNumber from tbl group by ssn, acctNumber
You can try this..
select SSN , AcctNumber, OpenDate
from (SELECT SSN , AcctNumber, OpenDate
, ROW_NUMBER() OVER ( PARTITION BY SSN, ORDER BY OpenDate ASC ) AS RN
FROM table) AS temp
WHERE temp.RN= 1
Given the following table
group | weight | category_id | category_name_plus
1 10 100 Ab
1 20 101 Bcd
1 30 100 Efghij
2 10 101 Bcd
2 20 101 Cdef
2 30 100 Defgh
2 40 100 Ab
3 10 102 Fghijkl
3 20 101 Ab
The "weight" is unique for each group and is also an indicator for the order of records inside the group.
What I want is to retrieve one record per group filtered by category_id, but only the record having the highest "weight" inside its "group".
Example for filtering by category_id = 100:
group | weight | category_id | category_name_plus
1 30 100 Efghij
2 40 100 Ab
Example for filtering by category_id = 101:
group | weight | category_id | category_name_plus
1 20 101 Bcd
2 20 101 Cdef
3 20 101 Ab
How can I select just these rows?
I tried fiddling with UNIQUE, MAX(category_id) etc. but I'm still unable to get the correct results. The main problem for me is to get the category_name_plus value here.
I am working with PostgreSQL 9.4(beta 3), because I also need various other niceties like "WITH ORDINALITY" etc.
The rank window function should do the trick:
SELECT "group", weight, category_id, category_name_plus
FROM (SELECT "group", weight, category_id, category_name_plus,
RANK() OVER (PARTITION BY "group"
ORDER BY weight DESC) AS rk
FROM my_table) t
WHERE rk = 1 AND category_id = 101
Note:
"group" is a reserved word in SQL, so it has to be surrounded by quotes in order to be used as a column name. It would probably be better, though, to replace it with a non-reserved word, such as "group_id".
Try something like:
SELECT DISTINCT ON (category_id) *
from your_table
order by category_id, weight desc