I’m doing a join between two tables in PostgreSQL, one has a primary key constraint on incidentnumber (opentickets) while the other table does not have the restraint and can have duplicate incidentnumbers (incommingtickets). The problem comes when trying to filter out duplicates. The query,
SELECT incommingtickets.*
FROM incommingtickets
LEFT JOIN opentickets
ON incommingtickets.incidentnumber = opentickets.incidentnumber
WHERE opentickets.incidentnumber IS NULL
AND incommingtickets.status NOT IN ('Closed','Cancelled', '')
works until it hits a duplicate, the I get the violates primary key message. If I add a distinct clause like,
SELECT DISTINCT ON (incommingtickets.incidentnumber) incommingtickets.*
FROM incommingtickets
LEFT JOIN opentickets
ON incommingtickets.incidentnumber = opentickets.incidentnumber
WHERE opentickets.incidentnumber IS NULL
AND incommingtickets.status NOT IN ('Closed','Cancelled', '')
I get an error,
pg_query(): Query failed: ERROR: missing FROM-clause entry for table
"incommingtickets" LINE 30: WHERE opentickets.incidentnumber =
incommingtickets.incident...
Use a WHERE clause that filters out the duplicates you don't want, although it's not very clear for me on why you want to join on a 'metric' such as number of tickets.
SELECT incommingtickets.*
FROM incommingtickets
WHERE incommingtickets.incidentnumber not in (
select
distinct
incidentnumber
FROM opentickets)
AND incommingtickets.status NOT IN ('Closed','Cancelled', '')
This way you are filetring out duplicates between both tables.
If what you want is to check or update the ticket's status of any tickets inside the opentickets table then try to get from the incommingtickets the maximum status like this:
WITH ticket_rows AS(
SELECT
rank() OVER (PARTITION BY ticket_id ORDER BY ticket_timestamp desc) as row_number,
ticket_id,
ticket_status,
ticket_timestamp
from incommingtickets
)
SELECT incommingtickets.*, opentickets_2.*
FROM opentickets o
LEFT JOIN ticket_rows ON ticket_rows.ticket_id= opentickets.ticket_id AND ticket_rows.row__number=1
If these are not your objectives pleae explain a bit better on what you are trying to achieve with that left join.
Related
I'm trying to get the sum of the total time that was spent sending all emails within a campaign.
Because of the joins in my query I end up with the 'processing_time' column duplicated over many rows. So running sum(s.processing_time) as send_time will always over represent how long it took to run.
select
c.id,
c.sender,
c.subject,
count(*) as total_items,
count(distinct s.id) as sends,
sum(s.processing_time) as send_time,
from campaigns c
left join sends s on c.id = s.campaigns_id
left join opens o on s.id = o.sends_id
group by c.id;
I'd ideally like to do something like sum(s.processing_time when distinct s.id) but I can't quite work out how to achieve that.
I have made other attempts using case but I always run into the same issue, I need to get the distinct rows based on the ID column, but work with another column.
Since you want statistics related to distinct s.id as well as c.id, group by both columns. Collect the (intermediate) data that you need,
and use this table as the inner table in a nested sub-select query.
In the outer select, group by c.id alone.
Since the inner select groups by s.id, values which are unique per s.id will not get double-counted when you sum/group by c.id.
SELECT id
, sender
, subject
, sum(total_items) as total_items
, sum(sends) as sends
, sum(processing_time) as send_time
FROM (
SELECT
c.id
, s.id as sid
, count(*) as total_items
, 1 as sends
, s.processing_time
, c.sender
, c.subject
FROM campaigns c
LEFT JOIN sends s on c.id = s.campaigns_id
LEFT JOIN opens o on s.id = o.sends_id
GROUP BY c.id, c.sender, c.subject, s.processing_time, s.id) t
GROUP BY id, sender, subject
ORDER BY id
Since the final table includes sender and subject, you'll need to group by these columns as well to avoid an error such as:
ERROR: column "c.sender" must appear in the GROUP BY clause or be used in an aggregate function
LINE 14: , c.sender
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;
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.
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 am trying to removing duplicate values which, for some reason, was imported in a specific Table.
There is no Primary Key in this table.
There is 27797 unique records.
Select distinct txdate, plunumber from itemaudit
Give me the correct records, but only displays the txdate, plunumber of course.
If it was possible to select all the fields but only select the distinct of txdate,plunumber I could export the values, delete the duplicated ones and re-import.
Or if its possible to delete the distinct values from the entire table.
If you select the distinct of all fields the value is incorrect.
To get all information on the duplicates, you simply need to query all information for the duplicate rows using a JOIN:
SELECT b.*
FROM (SELECT COUNT(*) as cnt, txdate, plunumber
FROM itemaudit
GROUP BY txdate, plunumber
HAVING COUNT(*) > 1) a
INNER JOIN itemaudit b ON a.txdate = b.txdate AND a.plunumber = b.plunumber
DELETE FROM itemaudit t1
WHERE EXISTS (
SELECT 1 FROM itemaudit t2
WHERE t1.txdate = t2.txdate and t1.plunumber = t2.plunumber
AND t1.RDB$DB_KEY < t2.RDB$DB_KEY
);