I am keep getting 'syntax error at end of input' and don't know why.
What I want to do is divide result of disease by result of total with showing condition_id in disease section.
select disease.condition_id, (disease::float/total::float) as prevalence
from (
select condition_id, count(person_id)
from a.condition
where condition_id=316139
group by condition_id
) as disease
join (
select count(distinct person_id) as total
from a.person
)as total;
Can someone please help me with this?
Thanks!
I don't have an exact fix for your current syntax, but I would phrase this query as a join with an aggregation over the entire tables:
SELECT
COUNT(*) FILTER (WHERE c.condition_id = 316139) /
COUNT(DISTINCT p.person_id) AS prevalence
FROM a.person p
LEFT JOIN a.condition c
ON p.person_id = c.person_id;
The main reason for your error is the missing join condition. The join operator requires a join condition (defined using ON).
But given the structure of your query I think you don't actually want a inner join, but a cross join between the two.
Additionally the expression disease::float is trying to cast a complete row to a float value, not a single column. I assume you wanted to alias the count aggregate to something, e.g. count(person_id) as num_persons
Using total::float is also ambiguous as you have a sub-query alias with that name and a column with that name. That is highly confusing, you should avoid that.
select disease.condition_id,
(disease.num_person::float / total.total::float) as prevalence
from (
select condition_id, count(person_id) as num_person
from a.condition
where condition_id = 316139
group by condition_id
) as disease
cross join (
select count(distinct person_id) as total
from a.person
) as total
Related
I have this SQL:
select * from `posts`
where `posts`.`deleted_at` is null
and `expire_at` >= '2017-03-26 21:23:42.000000'
and (
select count(distinct tags.id) from `tags`
inner join `post_tag` on `tags`.`id` = `post_tag`.`tag_id`
where `post_tag`.`post_id` = `posts`.`id`
and (`tags`.`tag` like 'PHP' or `tags`.`tag` like 'pop' or `tags`.`tag` like 'UI')
) >= 1
Is it possible order the results by number of tags in posts?
Maybe add there alias?
Any information can help me.
Convert your correlated subquery into a join:
select p.*
from posts p
join (
select pt.post_id,
count(distinct t.id) as tag_count
from tags t
inner join post_tag pt on t.id = pt.tag_id
where t.tag in ('PHP', 'pop', 'UI')
group by pt.post_id
) pt on p.id = pt.post_id
where p.deleted_at is null
and p.expire_at >= '2017-03-26 21:23:42.000000'
order by pt.tag_count desc;
Also, note that I changed the bunch of like and or to single IN because you are not matching any pattern i.e. there is no % in the string. So, better using single IN instead.
Also, if you have defined your table names, column names etc keeping keywords etc in mind, you shouldn't have the need to use the backticks. They make reading a query difficult.
I am trying to calculate a percentile using the percentile_cont() function in PostgreSQL using common table expressions. The goal is find the top 1% of accounts regards to their balances (called amount here). My logic is to find the 99th percentile which will return those whose account balances are greater than 99% of their peers (and thus finding the 1 percenters)
Here is my query
--ranking subquery works fine
with ranking as(
select a.lname,sum(c.amount) as networth from customer a
inner join
account b on a.customerid=b.customerid
inner join
transaction c on b.accountid=c.accountid
group by a.lname order by sum(c.amount)
)
select lname, networth, percentile_cont(0.99) within group
order by networth over (partition by lname) from ranking ;
I keeping getting the following error.
ERROR: syntax error at or near "order"
LINE 2: ...ame, networth, percentile_cont(0.99) within group order by n..
I am thinking that perhaps I forgot a closing brace etc. but I can't seem to figure out where. I know it could be something with the order keyword but I am not sure what to do. Can you please help me to fix this error?
This tripped me up, too.
It turns out percentile_cont is not supported in postgres 9.3, only in 9.4+.
https://www.postgresql.org/docs/9.4/static/release-9-4.html
So you have to use something like this:
with ordered_purchases as (
select
price,
row_number() over (order by price) as row_id,
(select count(1) from purchases) as ct
from purchases
)
select avg(price) as median
from ordered_purchases
where row_id between ct/2.0 and ct/2.0 + 1
That query care of https://www.periscopedata.com/blog/medians-in-sql (section: "Median on Postgres")
You are missing the brackets in the within group (order by x) part.
Try this:
with ranking
as (
select a.lname,
sum(c.amount) as networth
from customer a
inner join account b on a.customerid = b.customerid
inner join transaction c on b.accountid = c.accountid
group by a.lname
order by networth
)
select lname,
networth,
percentile_cont(0.99) within group (
order by networth
) over (partition by lname)
from ranking;
I want to point out that you don't need a subquery for this:
select c.lname, sum(t.amount) as networth,
percentile_cont(0.99) within group (order by sum(t.amount)) over (partition by lname)
from customer c inner join
account a
on c.customerid = a.customerid inner join
transaction t
on a.accountid = t.accountid
group by c.lname
order by networth;
Also, when using table aliases (which should be always), table abbreviations are much easier to follow than arbitrary letters.
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.
In SQL Server, I know for sure that the following query;
SELECT things.*
FROM things
LEFT OUTER JOIN (
SELECT thingreadings.thingid, reading
FROM thingreadings
INNER JOIN things on thingreadings.thingid = things.id
ORDER BY reading DESC LIMIT 1) AS readings
ON things.id = readings.thingid
WHERE things.id = '1'
Would join against thingreadings only once the WHERE id = 1 had restricted the record set down. It left joins against just one row. However in order for performance to be acceptable in postgres, I have to add the WHERE id= 1 to the INNER JOIN things on thingreadings.thingid = things.id line too.
This isn't ideal; is it possible to force postgres to know that what I am joining against is only one row without explicitly adding the WHERE clauses everywhere?
An example of this problem can be seen here;
I am trying to recreate the following query in a more efficient way;
SELECT things.id, things.name,
(SELECT thingreadings.id FROM thingreadings WHERE thingid = things.id ORDER BY id DESC LIMIT 1),
(SELECT thingreadings.reading FROM thingreadings WHERE thingid = things.id ORDER BY id DESC LIMIT 1)
FROM things
WHERE id IN (1,2)
http://sqlfiddle.com/#!15/a172c/2
Not really sure why you did all that work. Isn't the inner query enough?
SELECT t.*
FROM thingreadings tr
INNER JOIN things t on tr.thingid = t.id AND t.id = '1'
ORDER BY tr.reading DESC
LIMIT 1;
sqlfiddle demo
When you want to select the latest value for each thingID, you can do:
SELECT t.*,a.reading
FROM things t
INNER JOIN (
SELECT t1.*
FROM thingreadings t1
LEFT JOIN thingreadings t2
ON (t1.thingid = t2.thingid AND t1.reading < t2.reading)
WHERE t2.thingid IS NULL
) a ON a.thingid = t.id
sqlfiddle demo
The derived table gets you the record with the most recent reading, then the JOIN gets you the information from things table for that record.
The where clause in SQL applies to the result set you're requesting, NOT to the join.
What your code is NOT saying: "do this join only for the ID of 1"...
What your code IS saying: "do this join, then pull records out of it where the ID is 1"...
This is why you need the inner where clause. Incidentally, I also think Filipe is right about the unnecessary code.
I would like to do something like this:
CNT=2;
//[edit]
select avg(price) from (
select first :CNT p.Price
from Price p
order by p.Date desc
);
This does not work, Firebird does not allow :cnt as a parameter to FIRST. I need to average the first CNT newest prices. The number 2 changes so it can not be hard-coded.
This can be broken out into a FOR SELECT loop and break when a count is reached. Is that the best way though? Can this be done in a single SQL statement?
Creating the SQL as a string and running it is not the best fit either. It is important that the database compile my SQL statement.
You don't have to use CTE, you can do it directly:
select avg(price) from (
select first :cnt p.Price
from Price p
order by p.Date desc
);
You can use a CTE (Common Table Expression) (see http://www.firebirdsql.org/refdocs/langrefupd21-select.html#langrefupd21-select-cte) to select data before calculate average.
See example below:
with query1 as (
select first 2 p.Price
from Price p
order by p.Date desc
)
select avg(price) from query1