I have 2 tables which I'd like to join and..
A:
ID Otherfields..
1 ...
2
3
4
B:
ID aId Otherfields..
1 1 ...
2 1
3 2
4 1
So I'm perfectly capable of joining them by a.Id but how do get I get the count for the matches in Table B, like:
a.id count(b)
1 3
2 1
I figured it must be something with count() over() but cannot recall the exact use.
Thanks!
You can simply do this:
SELECT
A.ID, COUNT(b.ID)
FROM A
INNER JOIN B ON A.Id = b.aID
GROUP BY A.ID
You can have
SELECT A.ID, COUNT(b.ID)
FROM A
LEFT JOIN B ON A.Id = b.aID
GROUP BY A.ID
This will give you all a.IDs that don't exist in b.ID and hence show their count as 0.
E.g.,
ID Count
1 3
2 1
3 0
4 0
Related
I have 2 tables , one stores IDs and another logs for each ID , i would like to get sum of log for each ID and ID number from these 2 tables
A B
------- -------------
ID ID_C LOG
1 1 15
2 1 30
3 4 44
4 2 14
5 3 88
3 10
2 10
for getting sum query is
SELECT SUM(LOG) FROM B WHERE ID_C ='2' ;
notice ID and ID_C are same but name is different in tables
and for getting all ids available query is
SELECT ID FROM A ;
I would like to get the following table result
result
--------------------
ID SUM
1 45
4 44
2 24
3 98
I tried
SELECT SUM(LOG) FROM B WHERE ID_C in (SELECT ID FROM A ) ;
but it result in sum of all IDs
It looks like you just need a join aggregation here:
SELECT a.ID, SUM(b.LOG) AS SUM
FROM A a
INNER JOIN B b
ON b.ID_C = a.ID
GROUP BY a.ID
ORDER BY a.ID;
Note that the inner join will also remove ID values from the A table which no entries whatsoever in the B table, which seems to be the behavior you want.
you should use inner join and GROUP BY:
SELECT A.ID as ID, SUM(LOG) AS SumLOG
FROM A inner join B ON A.ID = B.ID_C
GROUP BY A.ID
if you needed can use where for ID filter.
I have three tables A,B and C.
A and B are connected a foreign key A.category_id=B.id ,
A and C have the same number of rows.
A
id category_id value1 value2
1 null 'A' null
2 null 'B' null
3 null 'C' null
4 null 'D' null
B
id category
1 0
2 1
C
id category
1 0
2 1
3 1
4 0
Expected result:
A
id value
1 1
2 2
3 2
4 1
I would like to receive updated A table where category_id will be id from table B based on table C category.
I have tried
UPDATE A SET
A.category_id = (
select B.id from A
left JOIN C
ON A.id = C.id
left join B on B.category=C.category
)
WHERE A.id IN (SELECT C FROM C WHERE A.id = C.id);
but then I received ORA-01427 single-row subquery returns more than one row tips
You are missing a correlation clause in the subquery:
update A
set category_id = (select B.id
from C join
B
on B.category = C.category
where A.id = C.id
)
where exists (select 1 from C where A.id = C.id);
To correlated a query, you refer to the outer reference typically in a where condition. You don't repeat the table reference in the from clause.
Note that an outer join is unnecessary. If there is no match, the value will be NULL.
i have following SQL table A in my database:
index, group, foo
1 A 2
2 A 2
3 A 0
4 A 1
5 B 2
6 B 1
7 C 1
There are few more groups and I need to write a query based on this filter table B. For each group in table A it's index should be equal or greater than index_egt from table B for the same group.
If the group is not listed in table B, the group won't be filtered.
index_egt, group
3 A
5 B
Expected result:
index, group, foo
3 A 0
4 A 1
5 B 2
6 B 1
7 C 1
Try this, the A.index>=B.index_egt will handle cases where the group is listed in TableB and the B.index_egt IS NULL will handle cases where the group is not listed:
SELECT
A.index,
A.group,
A.foo
FROM TableA AS A
LEFT JOIN TableB AS B ON A.group=B.group
WHERE A.index>=B.index_egt
OR B.index_egt IS NULL
select
a.*
from
A a
left join
B b ON b.group = a.group
where
a.index >= b.index_egt OR b.index_egt IS NULL
I always like this trick with coalesce
SELECT a.*
FROM a_table_with_no_name a
LEFT JOIN b_table_with_no_name b ON b.group = a.group
WHERE a.index >= COALESCE(b.index_egt,a.index)
I have two Tables
Let suppose A and B
Now suppose the structure of table A is Like that
id stock
37 1
40 1
37 1
40 1
37 1
37 1
And B is like that
id stock
37 1
37 1
40 1
Now i want to write a query that give me sum of specific id stock in (table A - Table B) and if that id does not exist in table B then only stock from A.
So i will expect result like that
id stock
40 1
37 2
I thought that left join will be possible option here and i write query like that
SELECT A.id,
SUM(CAST(isNull(A.Stock, 0) as int) - CAST(isNull(B.Stock, 0) as int) )'Stock'
from A
LEFT OUTER JOIN
B
ON A.id = B.id
group by A.id
But Problem is that the above query gives desired records but wrong quantity/Stocklevel as shown below:
id stock
37 0
40 1
How can I resolve Stock Level issue.
I guess you are looking for something like this.
select A.id, A.SumA - coalesce(B.SumB, 0) as stock
from (
select A.id, sum(A.stock) as SumA
from A
group by A.id
) as A
left outer join
(
select B.id, sum(B.stock) as SumB
from B
group by B.id
) as B
on A.id = B.id
Result:
id stock
----------- -----------
37 2
40 1
SE Data
SELECT A.id, A.Stock - isNull(B.stock, 0) as Stock from A
LEFT OUTER JOIN B
ON A.id = B.id
That would be it I think.
PS. you group by something that you did not include in your case scenario. Your expected result is also not understandable to me (it conflicts with your problem description)
i have 3 tables (A,B,C)
Table A -
ID Name
1 Sam
2 Manuel
3 Jane
Table B
ID Tab_A_ID Name
1 1 Meer
2 1 Kutti
3 2 Mikaro
Table C
ID Tab_B_ID Price
1 1 255.11
2 1 30.52
3 3 125.22
I need a query that shall pick up the top price for TableA-Name from TableC. So only 1 top price for 1 nae record.
e.g.-
Sam - 255.11
Manuel - 125.22
How can i get this?
To get the max price per entry in A:
SELECT a.Name,
MAX(c.price)
FROM a
INNER JOIN b
ON a.id = b.tab_a_id
INNER JOIN c
ON b.id = c.tab_b_id
GROUP BY a.id, a.name
To get the max price per entry A per entry B:
SELECT a.Name,
b.Name
MAX(c.price)
FROM a
INNER JOIN b
ON a.id = b.tab_a_id
INNER JOIN c
ON b.id = c.tab_b_id
GROUP BY a.id, b.id, a.name, b.name
Note that entries in A without corresponding entires in B or entries in B without corresponding entries in C will not appear in the result. Use LEFT JOIN if you want to include these in the result.