I'm working with a postgres database where I need to merge multiple rows into a row based on ID.
ID | A | B | C |
--------------------
1 | x | | |
1 | x | y | |
2 | x | | z |
3 | | y | |
3 | | | z |
A, B and C are bytea columns.
I need to merge it as follows:
ID | A | B | C |
--------------------
1 | x | y | |
2 | x | | z |
3 | | y | z |
The problem occurs when I do GROUP BY on ID, as I'm not able to find a appropriate aggregate function for bytea columns.
You can always do it with sub queries
WITH allID as (
SELECT distinct ID
FROM YourTable
)
SELECT
ID,
(SELECT A FROM yourTable yt where yt.ID = ai.ID ORDER BY A LIMIT 1) as A,
(SELECT B FROM yourTable yt where yt.ID = ai.ID ORDER BY B LIMIT 1) as B,
(SELECT C FROM yourTable yt where yt.ID = ai.ID ORDER BY C LIMIT 1) as C
FROM allID as ai
Related
I am trying to assign what amounts to a 'combinationid' to rows of my table, based on the values in the two columns below. Each product has a number of customers linked to it. For every combination of customers, I need to create a combination ID.
For example, the combination of customers for product 'a' is the same combination of customers for product 'c' (they both have customers 1, 2 and 3), so products a and c should have the same combination identifier ('customergroup'). However, products should not share the same customergroup if they only share some of the same customers - e.g. product b only has customers 1 and 2 (not 3), so should have a different customergroup to products 'a' and 'c'.
Input:
| productid | customerid |
|-----------|------------|
| a | 1 |
| a | 2 |
| a | 3 |
| b | 1 |
| b | 2 |
| c | 3 |
| c | 2 |
| c | 1 |
| d | 1 |
| d | 3 |
| e | 1 |
| e | 2 |
| f | 1 |
| g | 2 |
| h | 3 |
Desired output:
| productid | customerid | customergroup |
|-----------|------------|---------------|
| a | 1 | 1 |
| a | 2 | 1 |
| a | 3 | 1 |
| b | 1 | 2 |
| b | 2 | 2 |
| c | 3 | 1 |
| c | 2 | 1 |
| c | 1 | 1 |
| d | 1 | 3 |
| d | 3 | 3 |
| e | 1 | 2 |
| e | 2 | 2 |
| f | 1 | 4 |
| g | 2 | 5 |
| h | 3 | 6 |
or just
| productid | customergroupid |
|-----------|-----------------|
| a | 1 |
| b | 2 |
| c | 1 |
| d | 3 |
| e | 2 |
| f | 4 |
| g | 5 |
| h | 6 |
Edit: first version of this did include a description of my attempts. I currently have nested queries that basically give me a column for customer 1, 2, 3 etc and then uses dense rank to get the grouping. The problem is that is not dynamic for different numbers of customers and I did not know where to start for getting a dynamic result as above. Thanks for the replies.
Considering you haven't shown your efforts, or confirmed the version you're using, I've assumed you have the latest ("and greatest") version of SQL Server, which means you have access to STRING_AGG.
This doesn't give the groupings in the same order, but I'm going to also also that doesn't matter, and the grouping is just arbitrary. This gives you the following:
WITH VTE AS(
SELECT *
FROM (VALUES('a',1),
('a',2),
('a',3),
('b',1),
('b',2),
('c',3),
('c',2),
('c',1),
('d',1),
('d',3),
('e',1),
('e',2),
('f',1),
('g',2),
('h',3)) V(productid,customerid)),
Groups AS(
SELECT productid,
STRING_AGG(customerid,',') WITHIN GROUP (ORDER BY customerid) AS CustomerIDs
FROM VTE
GROUP BY productid),
Rankings AS(
SELECT productid,
CustomerIDs,
DENSE_RANK() OVER (ORDER BY CustomerIDs ASC) AS Grouping
FROM Groups)
SELECT V.productid,
V.customerid,
R.Grouping AS customergroupid
FROM VTE V
JOIN Rankings R ON V.productid = R.productid
ORDER BY V.productid,
V.customerid;
db<>fiddle.
If you aren't using SQL Server 2017, I suggest looking up the FOR XML PATH method for string aggregation.
Using Larnu's answer this is how I got the result for 2008:
WITH VTE AS(
SELECT *
FROM (VALUES('a','1'),
('a','2'),
('a','3'),
('b','1'),
('b','2'),
('c','3'),
('c','2'),
('c','1'),
('d','1'),
('d','3'),
('e','1'),
('e','2'),
('f','1'),
('g','2'),
('h','3')) V(productid,customerid)),
Groups AS(
SELECT productid, CustomerIDs = STUFF((SELECT N', ' + customerid
FROM VTE AS p2
WHERE p2.productid = p.productid
ORDER BY customerid
FOR XML PATH(N'')), 1, 2, N'')
FROM VTE AS p
GROUP BY productid),
Rankings AS(
SELECT productid,
CustomerIDs,
DENSE_RANK() OVER (ORDER BY CustomerIDs ASC) AS Grouping
FROM Groups)
SELECT V.productid,
V.customerid,
R.Grouping AS customergroupid
FROM VTE V
JOIN Rankings R ON V.productid = R.productid
ORDER BY V.productid,
V.customerid;
Thanks again for your assistance.
I need to take data from a table that looks like this:
name | server | instance | version | user
----------|----------|------------|----------|--------- -
package_a | x | 1 | 1 | AB
package_b | x | 1 | 1 | TL
package_a | x | 2 | 4 | SK
package_a | y | 1 | 2 | MD
package_c | y | 1 | 4 | SK
package_b | y | 2 | 1 | SK
package_a | y | 2 | 1 | TL
package_b | x | 2 | 3 | TL
package_c | x | 2 | 1 | TL
and I need to put it in a table like that:
name | v_x_1 | u_x_1 | v_x_2 | u_x_2 | v_y_1 | u_y_1 | v_y_2 | u_y_2
----------|-------|-------|-------|-------|-------|-------|-------|-------
package_a | 1 | AB | 4 | SK | 2 | MD | 1 | TL
package_b | 1 | TL | 3 | TL | NULL | NULL | 1 | SK
package_c | NULL | NULL | 1 | TL | 4 | SK | NULL | NULL
I already tried INSERT with (SUB)SELECT, tried to INSERT package names first using DISTINCT and UPDATE afterwards, played around with PIVOT and stuff like that.
But I'm rather new to SQL and programming in general, so I couldn't come up with a solution. Since I not only have a version number in the source table but also nvarchar columns, It seems like PIVOT won't be the way to go, right?
You can use PIVOT on a sub query that uses UNION to separate the user and version values.
insert into YourNewTable (name, [v_x_1],[u_x_1],[v_x_2],[u_x_2],[v_y_1],[u_y_1],[v_y_2],[u_y_2])
select *
from (
select name, cast([version] as varchar(30)) as value, concat('v_',[server],'_',instance) as title from YourTable
union all
select name, [user] as value, concat('u_',[server],'_',instance) as title from YourTable
) q
pivot (max(value) FOR title IN (
[v_x_1],[u_x_1],[v_x_2],[u_x_2],[v_y_1],[u_y_1],[v_y_2],[u_y_2]
)
) pvt;
being a novice sql user:
I have a simple table storing some records over night daily. table:
Table: T1
+----+-----+----+-----------+------------+
| Id | A | AB | Value | Date |
+----+-----+----+-----------+------------+
| 1 | abc | I | -48936.08 | 2013-06-24 |
| 2 | def | A | 431266.19 | 2013-06-24 |
| 3 | xyz | I | -13523.90 | 2013-06-24 |
| 4 | abc | A | 13523.90 | 2013-06-23 |
| 5 | xyz | I | -13523.90 | 2013-06-23 |
| 6 | def | A | 13523.90 | 2013-06-22 |
| 7 | def | I | -13523.90 | 2013-06-22 |
+----+-----+----+-----------+------------+
I would like to get all values of columns A,AB, Value for the latest Date on Column A filtered on AB = I
basically the result should look like:
+----+-----+----+-----------+------------+
| Id | A | AB | Value | Date |
+----+-----+----+-----------+------------+
| 1 | abc | I | -48936.08 | 2013-06-24 |
| 3 | xyz | I | -13523.90 | 2013-06-24 |
| 7 | def | I | -13523.90 | 2013-06-22 |
+----+-----+----+-----------+------------+
I have tried to use inner join twice on the same table but failed to come up with correct result.
any help would be appreciated.
thanks :)
This will work with sqlserver 2005+
;WITH a as
(
SELECT id, A,AB, Value, Date
, row_number() over (partition by A order by Date desc) rn
FROM t1
WHERE AB = 'I'
)
SELECT id, A,AB, Value, Date
FROM a WHERE rn = 1
; WITH x AS (
SELECT id
, a
, ab
, "value"
, "date"
, Row_Number() OVER (PARTITION BY a ORDER BY "date" DESC) As row_num
FROM your_table
WHERE ab = 'I'
)
SELECT *
FROM x
WHERE row_num = 1
I have a table with 4 columns and more than 100 million records.
Table Design:
ID char(12) PK
Type Char(2) PK (Values 1,2,3)
DCID varchar(10) Null
IND Varchar(2) Null (Values Y, N)
This needs to be pivoted like
ID, DCID1, DCID2, DCID3, IND1, IND2, IND3
If Type is having value 1,Then in the Pivoted table the DCID1 should have the value or if Type is 2 DCID2 should have the value and so on. Also correspoding IND also needs to be placed in IND1, IND2, IND3 like that.
How to pivot this?
My suggestion would be to look at using both the UNPIVOT and the PIVOT functions to get the result.
The UNPIVOT will be used to convert the DCI and IND multiple columns into multiple rows in a single column. Once that is done, then you can pivot the data back into columns.
The UNPIVOT code will be similar to this:
select id,
col +type as new_col,
value
from
(
select id,
type,
dcid,
cast(ind as varchar(10)) ind
from yt
) d
unpivot
(
value
for col in (DCID, IND)
) unpiv;
See SQL Fiddle with Demo. This gives a result:
| ID | NEW_COL | VALUE |
----------------------------------
| 1 | dcid1 | test |
| 1 | ind1 | Y |
| 2 | dcid2 | est |
| 2 | ind2 | Y |
The new_col contains the DCID and IND names and it has the type value concatenated to the end. This new value will be what you apply the PIVOT to:
select id, DCID1, DCID2, DCID3, IND1, IND2, IND3
from
(
select id,
col +type as new_col,
value
from
(
select id,
type,
dcid,
cast(ind as varchar(10)) ind
from yt
) d
unpivot
(
value
for col in (DCID, IND)
) unpiv
) src
pivot
(
max(value)
for new_col in (DCID1, DCID2, DCID3, IND1, IND2, IND3)
) piv;
See SQL Fiddle with Demo. The result will be:
| ID | DCID1 | DCID2 | DCID3 | IND1 | IND2 | IND3 |
-------------------------------------------------------------
| 1 | test | | | Y | | |
| 2 | | est | | | Y | |
| 3 | | | blah | | | Y |
| 4 | yes | | | N | | |
| 5 | | hs | | | N | |
| 6 | | | jr | | | N |
I have this table :
id | type | date
1 | a | 01/1/2012
2 | b | 01/1/2012
3 | b | 01/2/2012
4 | b | 01/3/2012
5 | a | 01/5/2012
6 | b | 01/5/2012
7 | b | 01/9/2012
8 | a | 01/10/2012
The POV is per date. if 2 rows contains the same date , so both will visible in the same line ( left join).
Same date can be shared by 2 rows max.
so this situation can't be :
1 | a | 01/1/2012
2 | b | 01/1/2012
3 | a | 01/1/2012
if in the same date there is group a and b show both of them in single line using left join
if in date there is only a group , show it as single line ( +null at the right side )
if in date there is only b group , show it as single line ( +null at the left side )
Desired result :
Date |typeA|typeB |a'id|b'id
01/1/2012 | a | b | 1 | 2
01/2/2012 | | b | | 3
01/3/2012 | | b | | 4
01/5/2012 | a | b | 5 | 6
01/9/2012 | | b | | 7
01/10/2012 | a | | 8 |
I know this suppose to be simple , but the main anchor of join here is the date.
The problem I've encountered is when I read line 1 , i search in the table all rows with the same date...fine. - its ok.
But when I read the second line , I do it also , and it yields the first row - which already was counted...
any help ?
here is the sql fiddle :
https://data.stackexchange.com/stackoverflow/query/edit/82605
I think you want a pivot
select
[date],
case when [a] IS null then null else 'a' end typea,
case when [b] IS null then null else 'b' end typeb,
a as aid,
b as bid
from yourtable src
pivot (max(id) for type in ([a],[b]))p
If you want to do it with joins..
select ISNULL(a.date, b.date), a.type,b.type, a.id,b.id
from
(select * from yourtable where type='a') a
full outer join
(select * from yourtable where type='b') b
on a.date = b.date