I've got a Table that stores messages
like this:
codMsg, message, anotherCod
1, 'hi', 1
2, 'hello', 1
3, 'wasup', 1
4, 'yo', 2
5, 'yeah', 2
6, 'gogogo', 3
I was wondering if is possible to select top 1 of each anotherCod
What I expect:
1, 'hi', 1
4, 'yo', 2
6, 'gogogo', 3
I want the whole line, not just the number of the anotherCod, so group by should not work
select mytable.*
from mytable
join (select min(codMsg) as codMsg, anotherCod from mytable group by 2) x
on mytable.codMsg = x.codMsg
SQL Server 2005+, Oracle :
SELECT codMsg,
message,
anotherCod
FROM
(
SELECT codMsg,
message,
anotherCod,
RANK() OVER (PARTITION BY anotherCod ORDER BY codMsg ASC) AS Rank
FROM mytable
) tmp
WHERE Rank = 1
SELECT
*
FROM
myTable
WHERE
codMSG = (SELECT MIN(codMsg) FROM myTable AS lookup WHERE anotherCod = myTable.anotherCod)
Related
Let's say I am returning the following table from a select
CaseId
DocId
DocumentTypeId
DocumentType
ExpirationDate
1
1
1
I797
01/02/23
1
2
2
I94
01/02/23
1
3
3
Some Other Value
01/02/23
I want to select ONLY the row with DocumentType = 'I797', then if there is no 'I797', I want to select ONLY the row where DocumentType = 'I94'; failing to find either of those two I want to take all rows with any other value of DocumentType.
Using SQL Server ideally.
I think I'm looking for an XOR clause but can't work out how to do that in SQL Server or to get all other values.
Similar to #siggemannen answer
select top 1 with ties
case when DocumentType='I797' then 1
when DocumentType='I94' then 2
else 3
end gr
,docs.*
from docs
order by
case when DocumentType='I797' then 1
when DocumentType='I94' then 2
else 3
end
Shortest:
select top 1 with ties
docs.*
from docs
order by
case when DocumentType='I797' then 1
when DocumentType='I94' then 2
else 3
end
Something like this perhaps:
select *
from (
select t.*, DENSE_RANK() OVER(ORDER BY CASE WHEN DocumentType = 'I797' THEN 0 WHEN DocumentType = 'I94' THEN 1 ELSE 2 END) AS prioorder
from
(
VALUES
(1, 1, 1, N'I797', N'01/02/23')
, (1, 2, 2, N'I94', N'01/02/23')
, (1, 3, 3, N'Some Other Value', N'01/02/23')
, (1, 4, 3, N'Super Sekret', N'01/02/23')
) t (CaseId,DocId,DocumentTypeId,DocumentType,ExpirationDate)
) x
WHERE x.prioorder = 1
The idea is to rank rows by 1, 2, 3 depending on document type. Since we rank "the rest" the same, you will get all rows if I797 and I94 is missing.
select * from YourTable where DocumentType = 'I797'
union
select * from YourTable t where DocumentType = 'I94' and (not exists (select * from YourTable where DocumentType = 'I797'))
union
select * from YourTable t where (not exists (select * from YourTable where DocumentType = 'I797' or DocumentType = 'I94' ))
I have a table with subsets. How to find reader id's with the same subsets as given id? For example:
Input reader = 4
The expected output: reader 1 and 5.
Subsets size is not always = 3 as in the example it can be dynamic. What is correct SQL query?
declare #t table(
reader int not null,
book int,
pages int
)
insert into #t (reader, book, pages)
select 1, 1, 100 union
select 1, 2, 201 union
select 1, 3, 301 union
select 2, 1, 100 union
select 2, 3, 101 union
select 2, 3, 301 union
select 3, 1, 100 union
select 3, 2, 101 union
select 3, 3, 301 union
select 4, 1, 100 union
select 4, 2, 201 union
select 4, 3, 301 union
select 5, 1, 100 union
select 5, 2, 201 union
select 5, 3, 301
select * from #t
This is a bit of a pain, but you can use a self-join:
with t as (
select t.*, count(*) over (partition by reader) as cnt
from #t t
)
select t.reader
from t left join
t t2
on t2.book = t.book and
t2.pages = t.pages and
t2.cnt = t.cnt and
t2.reader = 4
group by t.reader, t.cnt
having count(*) = t.cnt and
count(*) = count(t2.reader);
The left join is needed to avoid a subsetting relationship. That is, having all the books for "4" plus additional books.
This is a generic approach to handle relational division. It checks if set x contains all elements from set y (and perhaps more):
with reqd as (
select book, pages
from #t
where reader = 1
)
select t.reader
from #t as t
inner join reqd on t.book = reqd.book and t.pages = reqd.pages
group by t.reader
having count(reqd.book) = (select count(*) from reqd)
I want to get the price of an article for a specific customer.
There are several levels of prices which i ranked in my query.
So Article A has a price on rank 1, 4, 6. The result should always be the lowest ranked price.
Article B rank 3 ,5
So article A price is ranked 1 and Article b is price ranked 3.
My query is below .
SELECT p2.* FROM(
SElect ART_ID, MIN(RANG) RANG FROM (
Select p.ART_ID, p.betrag ,
CASE p.PREIS_EBENE WHEN 'KA' THEN 1 WHEN 'KW' THEN 2 WHEN 'W' THEN 7 WHEN 'A' THEN 6 ELSE 99 END RANG
FROM MDART a
INNER JOIN MDPRSVK p ON (a.KLIENT_ID = p.KLIENT_ID AND a.ART_ID = p.ART_ID)
WHERE ICP_KZ.IS_SET(KENNUNG_USER, 'P') = 1
ORDER BY RANG)
GROUP BY ART_ID) T
INNER JOIN MDPRSVK p2 ON (p2.ART_ID = T.ART_ID AND p2.PREIS_EBENE = p.PREIS_EBENE)
i want to have every article appearing only once in the result
You have tagged your request PL/SQL, so I guess your DBMS may be Oracle.
If I understand correctly, the table MDPRSVK contains several prices per ART_ID. And you want to select each ART_ID's best price (best to worst: 'KA' -> 'KW' -> 'A' -> 'W' -> any other PREIS_EBENE).
You can use a window function (ROW_NUMBER, RANK or DENSE_RANK) for this:
select *
from mdprsvk
order by row_number()
over (partition by art_id
order by decode(preis_ebene, 'KA', 1, 'KW', 2, 'A', 3, 'W', 4, 5))
fetch first row with ties;
This is standard SQL. In Oracle, FETCH FIRST is available as of version 12c. In earlier versions you'd use a subquery instead:
select *
from
(
select
mdprsvk.*,
row_number() over (partition by art_id
order by decode(preis_ebene, 'KA', 1, 'KW', 2, 'A', 3, 'W', 4, 5))
as rn
from mdprsvk
)
where rn = 1;
Or use OraclesKEEP FIRST`:
select art_id, max(betrag)
keep (dense_rank first
order by decode(preis_ebene, 'KA', 1, 'KW', 2, 'A', 3, 'W', 4, 5))
from mdprsvk
group by art_id;
It is not clear, how MDART comes into play. It looks like you want to restrict your results to articles for certain clients and KENNUNG_USER is the column in MDART to check. If so, add a WHERE clause:
where exists
(
select *
from mdart
where mdart.klient_id = mdprsvk.klient_id
and mdart.art_id = mdprsvk.art_id
and icp_kz.is_set(mdart.kennung_user, 'p') = 1
)
Or with IN instead of EXISTS:
where (klient_id, art_id) in
(
select klient_id, art_id
from mdart
where icp_kz.is_set(kennung_user, 'p') = 1
)
I'm trying to write an efficient SQL query to select 'before' and 'after' pages for the signup process. I have a solution using for loops which doesn't scale and am hoping to get a SQL native solution.
For a single clientId, I would want to get the latest pages before sign up and after signup (only 1 from each side of the join process).
The join process ALWAYS has /join/complete
Input:
clientId time path
1 0 /page1
1 10 /page2
1 20 /join/<random_token_id>
1 30 /join/<random_token_id>/step2
1 40 /join/complete
1 50 /page2
2 0 /page3
2 10 /join/complete
Output
ClientId Before After
1 /page2 /page2
2 /page3 null
I would be grateful if there is an easy solution in SQL. If it's complex, just leave it out. I will leave the code running overnight.
#standardSQL
WITH lineup AS (
SELECT clientId, time, path,
ROW_NUMBER() OVER(PARTITION BY clientId ORDER BY time) pos
FROM `project.dataset.table`
), start AS (
SELECT row.clientId, row.pos FROM (
SELECT ARRAY_AGG(t ORDER BY pos LIMIT 1)[OFFSET(0)] row
FROM lineup t WHERE STARTS_WITH(path, '/join/')
GROUP BY clientId)
), complete AS (
SELECT clientId, pos FROM lineup WHERE path = '/join/complete'
), before AS (
SELECT lineup.clientId, path FROM lineup JOIN start
ON lineup.clientId = start.clientId AND lineup.pos = start.pos - 1
), after AS (
SELECT lineup.clientId, path FROM lineup JOIN complete
ON lineup.clientId = complete.clientId AND lineup.pos = complete.pos + 1
)
SELECT clientId, before.path AS before, after.path AS after
FROM before FULL OUTER JOIN after USING (clientId)
You can test / play with above using dummy data from your question as below
#standardSQL
WITH `project.dataset.table` AS (
SELECT 1 clientId, 0 time, '/page1' path UNION ALL
SELECT 1, 10, '/page2' UNION ALL
SELECT 1, 20, '/join/<random_token_id>' UNION ALL
SELECT 1, 30, '/join/<random_token_id>/step2' UNION ALL
SELECT 1, 40, '/join/complete' UNION ALL
SELECT 1, 50, '/page2' UNION ALL
SELECT 2, 0, '/page3' UNION ALL
SELECT 2, 10, '/join/complete' UNION ALL
SELECT 3, 0, '/join/complete' UNION ALL
SELECT 3, 10, '/page4'
), lineup AS (
SELECT clientId, time, path,
ROW_NUMBER() OVER(PARTITION BY clientId ORDER BY time) pos
FROM `project.dataset.table`
), start AS (
SELECT row.clientId, row.pos FROM (
SELECT ARRAY_AGG(t ORDER BY pos LIMIT 1)[OFFSET(0)] row
FROM lineup t WHERE STARTS_WITH(path, '/join/')
GROUP BY clientId)
), complete AS (
SELECT clientId, pos FROM lineup WHERE path = '/join/complete'
), before AS (
SELECT lineup.clientId, path FROM lineup JOIN start
ON lineup.clientId = start.clientId AND lineup.pos = start.pos - 1
), after AS (
SELECT lineup.clientId, path FROM lineup JOIN complete
ON lineup.clientId = complete.clientId AND lineup.pos = complete.pos + 1
)
SELECT clientId, before.path AS before, after.path AS after
FROM before FULL OUTER JOIN after USING (clientId)
with result as
Row clientId before after
1 1 /page2 /page2
2 2 /page3 null
3 3 null /page4
How can I limit a result set to n distinct values of a given column(s), where the actual number of rows may be higher?
Input table:
client_id, employer_id, other_value
1, 2, abc
1, 3, defg
2, 3, dkfjh
3, 1, ldkfjkj
4, 4, dlkfjk
4, 5, 342
4, 6, dkj
5, 1, dlkfj
6, 1, 34kjf
7, 7, 34kjf
8, 6, lkjkj
8, 7, 23kj
desired output, where limit distinct=5 distinct values of client_id:
1, 2, abc
1, 3, defg
2, 3, dkfjh
3, 1, ldkfjkj
4, 4, dlkfjk
4, 5, 342
4, 6, dkj
5, 1, dlkfj
Platform this is intended for is MySQL.
You can use a subselect
select * from table where client_id in
(select distinct client_id from table order by client_id limit 5)
This is for SQL Server. I can't remember, MySQL may use a LIMIT keyword instead of TOP. That may make the query more efficient if you can get rid of the inner most subquery by using the LIMIT and DISTINCT in the same subquery. (It looks like Vinko used this method and that LIMIT is correct. I'll leave this here for the second possible answer though.)
SELECT
client_id,
employer_id,
other_value
FROM
MyTable
WHERE
client_id IN
(
SELECT TOP 5
client_id
FROM
(
SELECT DISTINCT
client_id
FROM
MyTable
) SQ
ORDER BY
client_id
)
Of course, add in your own WHERE clause and ORDER BY clause in the subquery.
Another possibility (compare performance and see which works out better) is:
SELECT
client_id,
employer_id,
other_value
FROM
MyTable T1
WHERE
T1.code IN
(
SELECT
T2.code
FROM
MyTable T2
WHERE
(SELECT COUNT(*) FROM MyTable T3 WHERE T3,code < T2.code) < 5
)
-- Using Common Table Expression in Microsoft SQL Server.
-- LIMIT function does not exist in MS SQL.
WITH CTE
AS
(SELECT DISTINCT([COLUMN_NAME])
FROM [TABLE_NAME])
SELECT TOP (5) [[COLUMN_NAME]]
FROM CTE;
This works for MS SQL if anyone is on that platform:
SET ROWCOUNT 10;
SELECT DISTINCT
column1, column2, column3,...
FROM
Table1
WHERE ...