Need to join two table without having cross join between them.
The join condition need to be made on Tabl.month = Tab2.month
Input
Table1 Table2
Month ID Month ID
1 a 1 a
1 b 1 b
1 c 2 g
2 d 3 i
2 e 3 j
3 f 3 k
Output:
Month_Tab1 ID_Tab1 Month_Tab2 ID_Tab2
1 a 1 a
1 b 1 b
1 c Null Null
2 d 2 g
2 e Null Null
3 f 3 i
Null Null 3 j
Null Null 3 k
The above o/p is required, without cross join, have tried full outer but cross join is happening as the ID is duplicate in both Tables. Left/Right join also cannt be applicable as either of the table might have larger set of ID's.
You want a full join, but with row_number() to identify the matches:
select t1.month month_tab1, t1.id id_tab1, t2.month month_tab2, t2.id id_tab2
from (
select t.*, row_number() over(partition by month order by id) rn from table1 t
) t1
full join (
select t.*, row_number() over(partition by month order by id) rn from table2 t) t2
on t2.month = t1.month and t2.rn = t1.rn
You can use a full outer join:
select
a.month,
a.id,
b.month,
b.id
from (
select month, id,
row_number() over(partition by month order by id) as n
from table1
) a
full outer join (
select month, id,
row_number() over(partition by month order by id) as n
from table2
) b on b.month = a.month and b.n = a.n
order by coalesce(a.month, b.month), coalesce(a.n, b.n)
Related
I have two datasets in Oracle Table1 and Table2.
When I run this:
SELECT A.ID, B.NUM_X
FROM TABLE1 A
LEFT JOIN TABLE2 B ON A.ID=B.ID
WHERE B.BOOK = 1
It returns this.
ID NUM_X
1 10
1 5
1 9
2 2
2 1
3 20
3 11
What I want are the DISTINCT ID where NUM_X is the MAX value, something like this:
ID NUM_x
1 10
2 2
3 20
You can use aggregation:
SELECT A.ID, MAX(B.NUM_X)
FROM TABLE1 A LEFT JOIN
TABLE2 B
ON A.ID = B.ID
WHERE B.BOOK = 1
GROUP BY A.ID;
If you wanted additional columns, I would recommend window functions:
SELECT A.ID, MAX(B.NUM_X)
FROM TABLE1 A LEFT JOIN
(SELECT B.*,
ROW_NUMBER() OVER (PARTITION BY ID ORDER BY NUM_X DESC) as seqnum
FROM TABLE2 B
) B
ON A.ID = B.ID AND B.seqnum = 1
WHERE B.BOOK = 1
GROUP BY A.ID;
I'd like to group by region where there are customerswho has type=a
region customer type score
A a a 1
A b b 2
A c a 3
B d c 4
B e d 5
C f a 6
C g c 7
Therefore after first step
region customer type score
A a a 1
A b b 2
A c a 3
C f a 6
C g c 7
And then I groupby in region
region sum(score)
A 6
C 13
also I'd like to extract customer whose type=a
region customer type
A a a
A c a
C f a
Then I'd like to merge above.
My desired result is like following
customer sum_in_region
a 6
c 6
f 13
Are there any way to achieve this?
My work is till the second step..
How can I proceed further?
SELECT t1.region,t1.customer, t1.type, t1.score
FROM yourTable t1
WHERE EXISTS (SELECT 1
FROM yourTable t2
WHERE t2.region = t1.region
AND t2.type = 'a');
Thanks
Join the table to a derived table that does your first two steps.
SELECT t3.customer,
x1.score
FROM yourtable t3
INNER JOIN (SELECT t1.region,
sum(score) score
FROM yourtable t1
WHERE EXISTS (SELECT *
FROM yourtable t2
WHERE t2.region = t1.region
AND t2.type = 'a')
GROUP BY t1.region) x1
ON x1.region = t3.region
WHERE t2.type = 'a';
You could use the windows functions to get your result; the first step filters for only rows where type is a, based on the region. The second step then gets the sum of scores, based again on the region, before selecting only customer and sum columns :
with filter_type_a as
(select region, customer, type, score
from
(select *,
sum(type=="a") over (partition by region) as counter
from your_table)
where counter > 0)
select customer, sum_region
from
(select customer, type,
sum(score) over (partition by region) as sum_region
from filter_type_a)
where type=="a";
You can use below query:
SQLFiddle
with country_tmp as
(SELECT t1.region,t1.customer, t1.type, t1.score
FROM country t1
WHERE EXISTS (SELECT 1
FROM country t2
WHERE t2.region = t1.region
AND t2.type = 'a'))
select y.customer, x.score from
(select a.region, sum(a.score) score from (
SELECT t1.region,t1.customer, t1.type, t1.score
FROM country_tmp t1) a
group by region) x , (SELECT t1.region,t1.customer, t1.type
FROM country_tmp t1
Where t1.type = 'a') y where x.region = y.region;
I have following table
ID Name Stage
1 A 1
1 B 2
1 C 3
1 A 4
1 N 5
1 B 6
1 J 7
1 C 8
1 D 9
1 E 10
I need output as below with parameters A and N need to select closest rows where difference between stage is smallest
ID Name Stage
1 A 4
1 N 5
I need to select rows where difference between stage is smallest
This query can make use of an index on (name, stage) efficiently:
WITH cte AS (
SELECT TOP 1
a.id AS a_id, a.name AS a_name, a.stage AS a_stage
, n.id AS n_id, n.name AS n_name, n.stage AS n_stage
FROM tbl a
CROSS APPLY (
SELECT TOP 1 *, stage - a.stage AS diff
FROM tbl
WHERE name = 'N'
AND stage >= a.stage
ORDER BY stage
UNION ALL
SELECT TOP 1 *, a.stage - stage AS diff
FROM tbl
WHERE name = 'N'
AND stage < a.stage
ORDER BY stage DESC
) n
WHERE a.name = 'A'
ORDER BY diff
)
SELECT a_id AS id, a_name AS name, a_stage AS stage FROM cte
UNION ALL
SELECT n_id, n_name, n_stage FROM cte;
SQL Server uses CROSS APPLY in place of standard-SQL LATERAL.
In case of ties (equal difference) the winner is arbitrary, unless you add more ORDER BY expressions as tiebreaker.
dbfiddle here
This solution works, if u know the minimum difference is always 1
SELECT *
FROM myTable as a
CROSS JOIN myTable as b
where a.stage-b.stage=1;
a.ID a.Name a.Stage b.ID b.Name b.Stage
1 A 4 1 N 5
Or simpler if u don't know the minimum
SELECT *
FROM myTable as a
CROSS JOIN myTable as b
where a.stage-b.stage in (SELECT min (a.stage-b.stage)
FROM myTable as a
CROSS JOIN myTable as b)
There are a lot of answers about how to select n rows from each group.
But what I am looking for is to select every row from top N group, for example I have the data below:
id group
1 a
2 a
3 b
4 c
5 c
6 d
7 d
.......
If I want to select Top 3 Group, my intended results as below:
1 a
2 a
3 b
4 c
5 c
How can I achieve this with Microsoft SQL server 2008?
One option is to use a subquery which selects the top N groups:
SELECT t1.id, t1.group
FROM yourTable t1
INNER JOIN
(
SELECT DISTINCT TOP(N) group
FROM yourTable
ORDER BY group
) t2
ON t1.group = t2.group
You could rank your rows by the group and then take only the top three:
SELECT [id], [group]
FROM (SELECT [id], [group], RANK() OVER (ORDER BY [group] ASC) rk
FROM mytable) t
WHERE rk <= 3
#Tim: I just modified your query.
SELECT t1.id, t1.group
FROM yourTable t1
INNER JOIN
(
SELECT TOP N group
FROM yourTable
GROUP BY group
--ORDER BY group USE IT IF YOU WANT
) t2
ON t1.group = t2.group
I have a table_1:
id custno
1 1
2 2
3 3
and a table_2:
id custno qty descr
1 1 10 a
2 1 7 b
3 2 4 c
4 3 7 d
5 1 5 e
6 1 5 f
When I run this query to show the minimum order quantities from every customer:
SELECT DISTINCT table_1.custno,table_2.qty,table_2.descr
FROM table_1
LEFT OUTER JOIN table_2
ON table_1.custno = table_2.custno AND qty = (SELECT MIN(qty) FROM table_2
WHERE table_2.custno = table_1.custno )
Then I get this result:
custno qty descr
1 5 e
1 5 f
2 4 c
3 7 d
Customer 1 appears twice each time with the same minimum qty (& a different description) but I only want to see customer 1 appear once. I don't care if that is the record with 'e' as a description or 'f' as a description.
First of all... I'm not sure why you need to include table_1 in the queries to begin with:
select custno, min(qty) as min_qty
from table_2
group by custno;
But just in case there is other information that you need that wasn't included in the question:
select table_1.custno, ifnull(min(qty),0) as min_qty
from table_1
left outer join table_2
on table_1.custno = table_2.custno
group by table_1.custno;
"Generic" SQL way:
SELECT table_1.custno,table_2.qty,table_2.descr
FROM table_1, table_2
WHERE table_2.id = (SELECT TOP 1 id
FROM table_2
WHERE custno = table_1.custno
ORDER BY qty )
SQL 2008 way (probably faster):
SELECT custno, qty, descr
FROM
(SELECT
custno,
qty,
descr,
ROW_NUMBER() OVER (PARTITION BY custno ORDER BY qty) RowNum
FROM table_2
) A
WHERE RowNum = 1
If you use SQL-Server you could use ROW_NUMBER and a CTE:
WITH CTE AS
(
SELECT table_1.custno,table_2.qty,table_2.descr,
RN = ROW_NUMBER() OVER ( PARTITION BY table_1.custno
Order By table_2.qty ASC)
FROM table_1
LEFT OUTER JOIN table_2
ON table_1.custno = table_2.custno
)
SELECT custno, qty,descr
FROM CTE
WHERE RN = 1
Demolink