given a query like so:
SELECT
id,
(SELECT COUNT(*)
FROM members
WHERE members.network_id = networks.id) AS mem_count
FROM
networks
WHERE mem_count > 2
With this query, the where clause breaks as it does not know what mem_count is... Why can't I use the as var in the where clause?
Thanks
While bernie suggested correct answer to the question, your query can be simplified to:
SELECT
network_id as id,
count(*)
FROM
members
GROUP BY
network_id
HAVING
count(*) > 2
Which, as an additional bonus, can be faster.
You've got the concept down. You just need the right syntax. You could re-write like this and have the added benefit of making your query ANSI-compliant:
SELECT
id,
m.mem_count
FROM
networks n
JOIN (
SELECT m.network_id,
COUNT(*) AS mem_count
FROM members
GROUP BY m.network_id
) m
ON m.network_id = n.id
AND m.mem_count > 2;
Try:
SELECT
id,
(SELECT COUNT(*) as mem_count
FROM members
WHERE members.network_id = networks.id)
FROM
networks
WHERE mem_count > 2
One way would be.
Select * From (
SELECT
id,
(SELECT COUNT(*)
FROM members
WHERE members.network_id = networks.id) AS mem_count
FROM
networks)) mem_counts
WHERE mem_count > 2
A join as suggested by Bernie would be better though. Basically you confused the parser. You get the same sort of issue with group by or order by when you use AS to alias a column name.
Related
SELECT lkey, max(votecount) FROM VOTES
WHERE ekey = (SELECT ekey FROM Elections where electionid='NR2019')
GROUP BY lkey
ORDER BY lkey ASC
Is there an easy way to get the pkey in this Statement?
Solution should look like this
Use DISTINCT ON:
SELECT DISTINCT ON (v.ikey) v.*
FROM VOTES v
INNER JOIN Elections e ON e.ekey = v.ekey
WHERE e.electionid = 'NR2019'
ORDER BY v.ikey, v.votecount DESC;
In plain English, the above query says to return the single record for each ikey value having the highest vote count.
I have a query like this:
SELECT
table1.*,
sum(table2.amount) as totalamount
FROM table1
join table2 on table1.key = table2.key
GROUP BY table1.*;
I got the error: column "table1.key" must appear in the GROUP BY clause or be used in an aggregate function.
Are there any way to group "all" field?
There is no shortcut syntax for grouping by all columns, but it's probably not necessary in the described case. If the key column is a primary key, it's enough when you use it:
GROUP BY table1.key;
You have to specify all the column names in group by that are selected and are not part of aggregate function ( SUM/COUNT etc)
select c1,c2,c4,sum(c3) FROM totalamount
group by c1,c2,c4;
A shortcut to avoid writing the columns again in group by would be to specify them as numbers.
select c1,c2,c4,sum(c3) FROM t
group by 1,2,3;
I found another way to solve, not perfect but maybe it's useful:
SELECT string_agg(column_name::character varying, ',') as columns
FROM information_schema.columns
WHERE table_schema = 'your_schema'
AND table_name = 'your_table
Then apply this select result to main query like this:
$columns = $result[0]["columns"];
SELECT
table1.*,
sum(table2.amount) as totalamount
FROM table1
join table2 on table1.key = table2.key
GROUP BY $columns;
Using ms-sql 2008 r2; am sure this is very straightforward. I am trying to identify where a unique value {ISIN} has been linked to more than 1 Identifier. An example output would be:
isin entity_id
XS0276697439 000BYT-E
XS0276697439 000BYV-E
This is actually an error and I want to look for other instances where there may be more than one entity_id linked to a unique ISIN.
This is my current working but it's obviously not correct:
select isin, entity_id from edm_security_entity_map
where isin is not null
--and isin = ('XS0276697439')
group by isin, entity_id
having COUNT(entity_id) > 1
order by isin asc
Thanks for your help.
Elliot,
I don't have a copy of SQL in front of me right now, so apologies if my syntax isn't spot on.
I'd start by finding the duplicates:
select
x.isin
,count(*)
from edm_security_entity_map as x
group by x.isin
having count(*) > 1
Then join that back to the full table to find where those duplicates come from:
;with DuplicateList as
(
select
x.isin
--,count(*) -- not used elsewhere
from edm_security_entity_map as x
group by x.isin
having count(*) > 1
)
select
map.isin
,map.entity_id
from edm_security_entity_map as map
inner join DuplicateList as dup
on dup.isin = map.isin;
HTH,
Michael
So you're saying that if isin-1 has a row for both entity-1 and entity-2 that's an error but isin-3, say, linked to entity-3 in two separe rows is OK? The ugly-but-readable solution to that is to pre-pend another CTE on the previous solution
;with UniqueValues as
(select distinct
y.isin
,y.entity_id
from edm_security_entity_map as y
)
,DuplicateList as
(
select
x.isin
--,count(*) -- not used elsewhere
from UniqueValues as x
group by x.isin
having count(*) > 1
)
select
map.isin
,map.entity_id
from edm_security_entity_map as map -- or from UniqueValues, depening on your objective.
inner join DuplicateList as dup
on dup.isin = map.isin;
There are better solutions with additional GROUP BY clauses in the final query. If this is going into production I'd be recommending that. Or if your table has a bajillion rows. If you just need to do some analysis the above should suffice, I hope.
I'm trying to achieve this
select
case
when Org_CD = '1111' or Org_CD in (select distinct New_Org_CD from #temp) then 'International'
end as 'Organisation',
count(*)
from #AnotherTempTable
group by
case
when Org_CD = '1111' or Org_CD in (select distinct New_Org_CD from #temp) then 'International'
end
I received this error:
Column '#AnotherTempTable.Org_Cd' is
invalid in the select list because it
is not contained in either an
aggregate function or the GROUP BY
clause.
Is it because I cannot use "in" keyword inside the case statements? If yes, any known workarounds would be more than helpful!
I'd try this...
select
Org_CD, count(*)
from
#AnotherTempTable A
JOIN
(select distinct New_Org_CD from #temp UNION SELECT '1111') T ON A.Org_CD = T.New_Org_CD
group by
Org_CD
You can't have an inline IN like this (CASE + aggregate)
If this is not OK, please give sample data and output
I solved it with a variation of gbn's solution using 'Union'. Thanks all.
What's the best way to do something like this in T-SQL?
SELECT DISTINCT ID
FROM Members,
INNER JOIN Comments ON Members.MemberId = Comments.MemberId
WHERE COUNT(Comments.CommentId) > 100
Trying to get the members who have commented more than 100 times. This is obviously invalid code but what's the best way to write this?
This should get you what you're after. I'm not saying this is the absolutely best way of doing it, but it's unlikely you'll find anything better.
SELECT ID
FROM Members
INNER JOIN Comments
ON Members.MemberId = Comments.MemberId
GROUP BY ID
HAVING COUNT(*) > 100
I like using a subquery.
SELECT DISTINCT m.ID
FROM Members m
WHERE (SELECT COUNT(c.CommentID)
FROM Comments c
WHERE c.MemberID = m.MemberID) > 100
Try
SELECT ID
FROM Members
INNER JOIN (SELECT MemberID FROM Comments
GROUP BY MemberID HAVING COUNT(CommentId) > 100)
AS CommentCount ON Members.MemberID = CommentCount.CommentID