I have a table that looks like so:
Name Age Num_Hobbies Num Shoes
Jane 31 10 2
Bob 23 3 4
Jane 60 2 200
Jane 31 100 6
Bob 10 8 7
etc etc
I would like to group this table by Name and Age, and at random pick one row from the rest of the columns.
In pandas, I would do the following:
df.groupby(['Name', 'Age']).apply(lambda x: x.sample(n=1))
In hive, I know how to create the group, but not how to choose a single random sample from group.
I saw this question on stack overflow: How to sample for each group in hive?
However, I do not understand how to apply Dynamic partitions or Hive bucketing to select a single sample from a group.
You can use rank() or row_number() with rand()
select * from
(
select name,age,rank() (partition by name,age order by rand()) as rank
from table
) t
where rank = 1
Related
It seems to simple, but not getting desired results
I have a table with there data
Team_id, Player_id, Player_name Game_cd
1 100 abc 24
1 1000 xyz 24
1 588 ert 24
1 500 you 24
2 600 ops 24
2 700 dps 24
2 900 lmv 24
2 200 hmv 24
I have to write a query to get a result like this
Home_team home_plr_id home_player away_team away_plr_id away_player
1 100 abc 2 600 ops
1 1000 xyz 2 900 lmv
The query I wrote
select f1.Team_id as home_team,
f1.player_id as home_plr_id,
f1.player_Name as home_player,
f2.Team_id as away_team,
f2.player_id as away_plr_id,
f2.player_Name as home_player
from game f1, game f2
where
f1.team_id<> f2.team_id and
f1.game_cd = f2.game_cd
Alternative to #Radagast81's self-join is pivot, available in your Oracle version:
select home_plr_id, home_plr_name, away_plr_id, away_plr_name
from (select game.*,
row_number() over (partition by team_id order by player_id) rn
from game)
pivot (max(player_id) plr_id, max(player_name) plr_name
for team_id in (1 home, 2 away))
SQL Fiddle
Players have to be numbered somehow (here by ID), it can be done by name, null or even random. This numbering is needed only to put them in same rows. Pivot works also if numbers of players in teams differs.
It is not clear how you want to pair a home player with an away player. But provided that you don't care about that, the following might be what you are looking for:
WITH game_p AS (SELECT team_id, player_id, player_name, game_cd
, ROW_NUMBER() over (PARTITION BY team_id, game_cd ORDER BY player_id) pos
, dense_rank() over (PARTITION BY game_cd ORDER BY team_id) team_pos
FROM game)
SELECT NVL(f1.game_cd, f2.game_cd) AS game_cd
, f1.Team_id as home_team
, f1.player_id as home_plr_id
, f1.player_Name as home_player
, f2.Team_id as away_team
, f2.player_id as away_plr_id
, f2.player_Name as away_player
FROM (SELECT * FROM game_p WHERE team_pos = 1) f1
FULL JOIN (SELECT * FROM game_p WHERE team_pos = 2) f2
ON f1.game_cd = f2.game_cd
AND f1.pos = f2.pos
The new column POS gives any player of each team a position to pair them with the other team.
The new column TEAM_POS is to get the team_id mapped to the values 1 and 2, as the team_id's can differ per game.
Finally do a FULL JOIN to get the final list. If the number of players are allways the same for both teams you can do a normal join instead...
I have two tables affiliation and customer, in that i have data like this
aff_id From_cus_id
------ -----------
1 10
2 20
3 30
4 40
5 50
cust_id cust_aff_id
------- -------
10
20
30
40
50
i need to update data for cust_aff_id column from affiliation table which is aff_id like below
cust_id cust_aff_id
------- -------
10 1
20 2
30 3
40 4
50 5
could u please give reply if anyone knows......
Oracle doesn't have an UPDATE with join syntax, but you can use a subquery instead:
UPDATE customer
SET customer.cust_aff_id =
(SELECT aff_id FROM affiliation WHERE From_cus_id = customer.cust_id)
merge into customer t2
using affiliation t1 on (t1.From_cus_id =t2.cust_id )
WHEN MATCHED THEN
update set t2.cust_aff_id = t1.aff_id
;
Here is an update with join syntax. This, quite reasonably, works only if from_cus_id is primary key in the first table and cust_id is foreign key in the second table, referencing the first table. Without these conditions, the requirement doesn't make much sense in the first place anyway... but Oracle requires that these constraints be stated explicitly in the tables. This is also reasonable on Oracle's part IMO.
update
( select t1.aff_id, t2.cust_aff_id
from affiliation t1 join customer t2 on t2.cust_id = t1.from_cus_id) j
set j.cust_aff_id = j.aff_id;
I have done SQL queries but have not done any procedure writing that uses loops so I am at a lost here. I'm using Oracle SQL Developer. Can be done in SQL or PL/SQL
I have a table that resemble this:
Person_ID Score Name Game_ID
1 10 jack 1
1 20 jack 2
2 15 carl 1
2 3 carl 3
4 17 steve 1
How can I loop through this table so that I can grab a players total score for all games played. Result would be like this:
Person_ID Score Name
1 30 jack
2 18 carl
4 17 steve
Also extra credit what If i wanted to just grab say games 1 2?
EDIT: Sorry for not being clear but I do need to do this with a loop even though it can be done without it.
Solution after post edition
This procedure list scores for given game_id. If you omit parameter all games will be summed:
create or replace procedure player_scores(i_game_id number default null) as
begin
for o in (select person_id, name, sum(score) score
from games where game_id = nvl(i_game_id, game_id)
group by person_id, name)
loop
dbms_output.put_line(o.person_id||' '||o.name||' '||o.score);
end loop;
end player_scores;
Previous solution:
You don't need procedure for that, just simple query:
select person_id, name, sum(score)
from your_table
where game_id in (1, 2)
group by person_id, name
I have two tables like below. Basically i want to join both of them and expected the result like below.
First 3 rows of table 2 does not have any activity id just empty.
All fields are tab separated. Category "33" is having three description as per table 2.
We need to make use of "Activity ID" to get the result for "33" category as there are 3 values for that.
could anyone tell me how to achieve this output?
TABLE: 1
Empid Category ActivityID
44126 33 TRAIN
44127 10 UFL
44128 12 TOI
44129 33 UNASSIGNED
44130 15 MICROSOFT
44131 33 BENEFITS
44132 43 BENEFITS
TABLE 2:
Category ActivityID Categdesc
10 billable
12 billable
15 Non-billable
33 TRAIN Training
33 UNASSIGNED Bench
33 BENEFITS Benefits
43 Benefits
Expected Output:
44126 33 Training
44127 10 Billable
44128 12 Billable
44129 33 Bench
44130 15 Non-billable
44131 33 Benefits
44132 43 Benefits
It's little difficult to do this Hive as there are many limitations. This is how I solved it but there could be a better way.
I named your tables as below.
Table1 = EmpActivity
Table2 = ActivityMas
The challenge comes due to the null fields in Table2. I created a view and Used UNION to combine result from two distinct queries.
Create view actView AS Select * from ActivityMas Where Activityid ='';
SELECT * From (
Select EmpActivity.EmpId, EmpActivity.Category, ActivityMas.categdesc
from EmpActivity JOIN ActivityMas
ON EmpActivity.Category = ActivityMas.Category
AND EmpActivity.ActivityId = ActivityMas.ActivityId
UNION ALL
Select EmpActivity.EmpId, EmpActivity.Category, ActView.categdesc from EmpActivity
JOIN ActView ON EmpActivity.Category = ActView.Category
)
You have to use top level SELECT clause as the UNION ALL is not directly supported from top level statements. This will run total 3 MR jobs. ANd below is the result I got.
44127 10 billable
44128 12 billable
44130 15 Non-billable
44132 43 Benefits
44131 33 Benefits
44126 33 Training
44129 33 Bench
I'm not sure if I understand your question or your data, but would this work?
select table1.empid, table1.category, table2.categdesc
from table1 join table2
on table1.activityID = table2.activityID;
Let's say I have table data similar to the following:
123456 John Doe 1 Green 2001
234567 Jane Doe 1 Yellow 2001
234567 Jane Doe 2 Red 2001
345678 Jim Doe 1 Red 2001
What I am attempting to do is only isolate the records for Jane Doe based upon the fact that she has more than one row in this table. (More that one sequence number)
I cannot isolate based upon ID, names, colors, years, etc...
The number 1 in the sequence tells me that is the first record and I need to be able to display that record, as well as the number 2 record -- The change record.
If the table is called users, and the fields called ID, fname, lname, seq_no, color, date. How would I write the code to select only records that have more than one row in this table? For Example:
I want the query to display this only based upon the existence of the multiple rows:
234567 Jane Doe 1 Yellow 2001
234567 Jane Doe 2 Red 2001
In PL/SQL
First, to find the IDs for records with multiple rows you would use:
SELECT ID FROM table GROUP BY ID HAVING COUNT(*) > 1
So you could get all the records for all those people with
SELECT * FROM table WHERE ID IN (SELECT ID FROM table GROUP BY ID HAVING COUNT(*) > 1)
If you know that the second sequence ID will always be "2" and that the "2" record will never be deleted, you might find something like:
SELECT * FROM table WHERE ID IN (SELECT ID FROM table WHERE SequenceID = 2)
to be faster, but you better be sure the requirements are guaranteed to be met in your database (and you would want a compound index on (SequenceID, ID)).
Try something like the following. It's a single tablescan, as opposed to 2 like the others.
SELECT * FROM (
SELECT t1.*, COUNT(name) OVER (PARTITION BY name) mycount FROM TABLE t1
)
WHERE mycount >1;
INNER JOIN
JOIN:
SELECT u1.ID, u1.fname, u1.lname, u1.seq_no, u1.color, u1.date
FROM users u1 JOIN users u2 ON (u1.ID = u2.ID and u2.seq_no = 2)
WHERE:
SELECT u1.ID, u1.fname, u1.lname, u1.seq_no, u1.color, u1.date
FROM users u1, thetable u2
WHERE
u1.ID = u2.ID AND
u2.seq_no = 2
Check out the HAVING clause for a summary query. You can specify stuff like
HAVING COUNT(*) >= 2
and so forth.