Query to restrict results from left join - sql

I have the following query
select S.id, X.id, 15,15,1 from schema_1.tbl_2638 S
JOIN schema_1.tbl_2634_customid X on S.field_1=x.fullname
That returns the following results, where you can see the first column is duplicated on matches to the 2nd table.
1 1 15 15 1
2 3 15 15 1
2 2 15 15 1
3 5 15 15 1
3 4 15 15 1
I'm trying to get a query that would just give me a single row per 1st ID, and the min value from 2nd ID. So I want a result that would be:
1 1 15 15 1
2 2 15 15 1
3 4 15 15 1
I'm a little rust on my SQL skills, how would I write the query to provide the above result?

From your result you can do,this to achieve your result, for much more compicated structures, you can always take a look at window fucntions
select S.id, MIN(X.id) x_id, 15,15,1 from schema_1.tbl_2638 S
JOIN schema_1.tbl_2634_customid X on S.field_1=x.fullname
GROUP BY 1,3,4,5
window function can be used, need always a outer SELECT
SELECT
s_id,x_idm a,b,c
FROM
(select S.id as s_id, X.id as x_id, 15 a ,15 b,1 c
, ROW_NUMBER() OVER (PARTITION BY S.id ORDER BY X.id ASC) rn
from schema_1.tbl_2638 S
JOIN schema_1.tbl_2634_customid X on S.field_1=x.fullname)
WHERE rn = 1
Or as CTE
WITH CTE as (select S.id as s_id, X.id as x_id, 15 a ,15 b,1 c
, ROW_NUMBER() OVER (PARTITION BY S.id ORDER BY X.id ASC) rn
from schema_1.tbl_2638 S
JOIN schema_1.tbl_2634_customid X on S.field_1=x.fullname)
SELECT s_id,x_id,a,b,c FROM CTE WHERE rn = 1

Related

Select quantity on a 1st table based on a total quantity the 2nd table

Table 1
ID
Grp
Qty
1
A
5
2
A
4
3
B
5
4
B
3
5
B
2
6
C
14
7
D
1
8
D
1
9
E
2
10
E
2
11
E
1
12
E
1
Table 2
ID
Grp
Qty
1
A
7
2
B
9
3
C
13
4
D
1
5
E
4
Select/Output
ID
Grp
Qty
1
A
0
2
A
2
3
B
0
4
B
0
5
B
1
6
C
1
7
D
0
8
D
1
9
E
0
10
E
0
11
E
1
12
E
1
I want to select a row on a 1st table with a specific quantity based on the total quantity of the 2nd table. The result is on the 3rd table. Please see sample tables above, I really appreciate a help, thank you so much and sorry it was my first time asking a question here.
I have tried this code on both 2 tables
WITH tbl AS(
SELECT ID,
Qty,
Grp,
ROW_NUMBER() OVER (PARTITION BY Grp)AS Rown,
SUM(Qty) OVER (PARTITION BY Grp)AS Total
FROM Table1
)
SELECT * FROM tbl WHERE Rown = 1
But I am not able to select the specific rows on Table 1 because it only select the 1st row and total the quantity. Every row on table 1 has its own quantity.
You could use a cumulative windowed aggregates and then a CASE expression to achieve this:
--Saple Data
WITH Table1 AS(
SELECT *
FROM (VALUES(1,'A',5),
(2,'A',4),
(3,'B',5),
(4,'B',3),
(5,'B',2),
(6,'C',14))V(ID,Grp,Qty)),
Table2 AS(
SELECT *
FROM (VALUES(1,'A',7),
(2,'B',9),
(3,'C',13))V(ID,Grp,Qty)),
--Solution
CTE AS(
SELECT T1.ID,
T1.Grp,
T1.Qty,
SUM(T1.Qty) OVER (PARTITION BY T1.Grp ORDER BY T1.Id
ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS RunningQty,
T2.Qty AS T2Qty
FROM Table1 T1
JOIN Table2 T2 ON T1.Grp = T2.Grp)
SELECT C.ID,
C.Grp,
CASE WHEN C.RunningQty <= C.T2Qty THEN C.Qty
ELSE C.T2Qty - LAG(C.RunningQty,1,0) OVER (PARTITION BY C.Grp ORDER BY C.ID)
END AS Qty
FROM CTE C;

SQL query to partition rows into groups where lag (difference between rows) is greater than some value

Suppose I have a table like
id
1
3
4
10
12
19
and I'd like to group the ids (in sorted order) into the same group if they differ by 5 or less, and a new group if they differ by 6 or more. So the output would be:
id
group
1
1
3
1
4
1
10
2
12
2
19
3
Is this possible in SQL? It will be a query in Trino, and I see they have commands like lag and partition. Has anyone made a query like this that can help out?
You can use a cte with lead:
with cte(id, l1) as (
select t.id, abs(coalesce(lead(t.id) over (order by t.id), 0) - t.id) < 6 from tbl t
)
select c.id, (select sum(c1.id < c.id and c1.l1 = 0) from cte c1) + 1 from cte c

PSQL, adding a "step increasing" column

have this values in a table column select a from tab:
a
1
2
3
4
5
6
7
15
16
18
Using a variable=3, how can create column b starting with min(a) and with the following values:
a
b
1
1
2
1
3
1
4
4
5
4
6
4
7
7
15
15
17
15
18
18
something like: for each a (ordered) maintain the value at most for 3, otherwise reset.
Thanks,
AAWNSD
I think you want window functions and groups of three based on arithmetic on a:
select a,
min(a) over (partition by ceiling(a / 3.0)) as b
from tab;
Here is a db<>fiddle.
Hmmm . . . I realize that the above returns "16" for the last row rather than 18. My above interpretation may not be correct. You may be saying that you want groups -- once they start -- to never exceed the group starting value plus 2.
If so, one approach is a recursive CTE:
with recursive tt as (
select a, row_number() over (order by a) as seqnum
from tab
),
cte as (
select a, seqnum, a as grp
from tt
where seqnum = 1
union all
select tt.a, tt.seqnum,
(case when tt.a <= grp + 2 then grp else tt.a end)
from cte join
tt
on tt.seqnum = cte.seqnum + 1
)
select *
from cte;

Smarter GROUP BY

Consider Table like this.
I will call it Test
Id A B C D
1 1 1 8 25
2 1 2 5 35
3 1 3 2 75
4 2 2 2 45
5 3 2 5 26
Now I want rows with max 'Id' Grouped by 'A'
Id A B C D
3 1 3 2 75
4 2 2 2 45
5 3 2 5 26
-
--Work, but I do not want
SELECT MAX(Id), A FROM Test GROUP BY A
--I want but do not work
SELECT MAX(Id), A, B, C, D FROM Test GROUP BY A
--Work but I do not want
SELECT MAX(Id), A, B, C, D FROM Test GROUP BY A, B, C, D
--Work and I want
SELECT old.Id, old.A, new.B, new.C, new.D
FROM(
SELECT
MAX(Id) AS Id, A
FROM
Test GROUP BY A
)old
JOIN Test new
ON old.Id = new.Id
Is there a better way to write last query without join
Most databases support window functions:
select *
from (
select *, row_number() over (partition by a order by id desc) rn
from test
) t
where rn = 1
Most DBMS now support Common Table Expressions (CTE). You can use one.
;with maxa as (
select row_number() over(partition by a order by id desc) rn,
id,a,b,c,d from test
)
select id,a,b,c,d
from maxa
where rn=1

MS Sql Server, same column with a different row neighbors

I need a little help on a SQL query. I could not get the result that I wanted.
ID I10 H 10NS HNS CC NSCC
0 1 1 1 1 14 14
1 0 1 0 1 6 2
1 0 2 0 2 12 2
1 0 3 0 3 17 4
1 0 3 0 3 18 4
1 0 3 0 3 19 4
1 0 3 0 3 20 4
What I want to have is one from each ID with highest CC
For example,
ID I10 H 10NS HNS CC NSCC
0 1 1 1 1 14 14
1 0 3 0 3 20 4
I tried with this code:
SELECT a.ID, b.name, a.i10 as[i-10-index], a.h as[h-index], 10ns as[i-10-index based on non-self-citation], a.hns as [h-index based on non-self-citation],
max(a.[Citation Count]), (a.[Non-Self-Citation Count])
FROM tbl_lpNumerical as a
join tbl_lpAcademician as b
on a.ID= (b.ID-1)
GROUP BY a.ID, b.name, a.i10, a.h, a.10ns, a.hns,
a.[Non-Self-Citation Count]
order by a.ID desc
However, I could not get the desired results.
Thank you for your time.
You can simply get all the row where not exist another row with an higher CC
SELECT n.*
FROM tbl_lpNumerical n
WHERE NOT EXISTS ( SELECT 'b'
FROM tbl_lpNumerical n2
WHERE n2.ID = n.ID
AND n2.CC > n.CC
)
In SQL Server, you can use row_number() for this. Based on your sample data`, something like:
select sd.*
from (select sd.*, row_number() over (partition by id order by cc desc) as seqnum
from sampledata sd
) sd
where seqnum = 1;
I have no idea what your query has to do with the sample data. If it generates the data, then you can use a CTE:
with sampledata as (
<some query here>
)
select sd.*
from (select sd.*, row_number() over (partition by id order by cc desc) as seqnum
from sampledata sd
) sd
where seqnum = 1;
The following query will select a single row from each ID partition: the one with the highest CC value:
SELECT *
FROM (SELECT *,
ROW_NUMBER() OVER (PARTITION BY ID ORDER BY CC DESC) AS rn
FROM mytable) t
WHERE t.rn = 1
If there can be multiple rows having the same CC max value and you want all of them selected, then you can replace ROW_NUMBER() with RANK().