I have a table with date attribute and i need to do a query that gets the MIN date and the next of the MIN date
And I tried that :
select min(SC.TIMESTAMP) as minDate, result.TIMESTAMP
from Event SC
INNER JOIN
(SELECT TIMESTAMP from Event
HAVING TIMESTAMP > min(SC.TIMESTAMP)
) as result on result.BUSINESSID1 = SC.BUSINESSID1
where SC.BUSINESSSTEP = 'CONTAINER_PLACING_EVENT'
and SC.LOCATIONCODE = '1';
Could you please advice how to do that ?
Thanks in Advance
Perhaps you can rearrange your query into this form:
select
min(TS), min(TS2)
from
event,
(select TS as TS2 from event where TS > (select min(TS) from event))
Add extra criteria as desired. I would try to rewrite yours, but it isn't entirely clear what the criteria for the count are supposed to be. If you are expecting more than one row (for example, the min and min2 of each LOCATIONCODE) then you will probably want a GROUP BY in there.
Also, I wouldn't call a column TIMESTAMP as it is a reserved word.
You can use the ROW_NUMBER() OLAP Function:
SELECT *
FROM (
SELECT
TIMESTAMP
,ROW_NUMBER() OVER (
PARTITION BY BUSINESSSTEP, LOCATIONCODE
ORDER BY TIMESTAMP ASC
) AS RN
FROM EVENT
WHERE BUSINESSSTEP = 'CONTAINER_PLACING_EVENT'
AND LOCATIONCODE = '1'
) A
WHERE RN < 3
This will return as rows instead of columns, but it should get you what you want. If you think your original query would have returned multiple rows (for multiple entities), you can change the PARTITION BY clause to include the column that makes them distinct.
Related
I have a jsonb column in my table - it contains array of json objects
one of fields in these objects is a date.
Now i added new column in my table of type timestamp.
And now i need statement which hepls me to update new column with most recent date value from jsonb array column af a same record.
Following statement works great on selecting most recent date from jsonb array column of certain record:
select history.date
from document,
jsonb_to_recordset(document.history) as history(date date)
where document.id = 'd093d6b0-702f-11eb-9439-0242ac130002'
order by history.date desc
limit 1;
On update i have tried following:
update document
set status_recent_change_date = subquery.history.date
from (
select id, history.date
from document,
jsonb_to_recordset(document.history) as history(date date)
) as subquery
where document.id = subquery.id
order by history.date desc
limit 1;
Last statement does not working.
demo:db<>fiddle
UPDATE document d
SET status_recent_change_date = s.date
FROM (
SELECT DISTINCT ON (id)
*
FROM document,
jsonb_to_recordset(document.history) AS history(date date)
ORDER BY id, history.date DESC
) s
WHERE d.id = s.id;
Using LIMIT would not work because you limit the entire output of your SELECT statement. But you want to limit the output of each document.id. This can be done using DISTINCT ON (id).
This result can be used to update each record using their id values.
You most likely don't need to use LIMIT command.
It is enough to do the sorting inside SUBQUERY:
UPDATE document SET status_recent_change_date = subquery.hdate
FROM (
SELECT id, history.date AS hdate
FROM document, jsonb_to_recordset(document.history) AS history(date date)
ORDER BY history.date DESC
) AS subquery
WHERE document.id = subquery.id
I'm looking for a way to concatenate timestamp in two difference row, for an example, I have this table:
I want it to be grouped by weekday and concatenate the min(start_hour) with max(start_hour), to get something like this
and I'm using this query to retrieve the first image result
The query below should give you what you are looking for provided the information supplied. I made some assumptions. That the '00:00:00' in the start and end hours is not a valid time and can be ignored. If they should be considered valid, then Friday's output would be one entry of '00:00:00' - '11:30:00'.
I created two CTEs, one for the start hours and the other for the end hours where the values are not '00:00:00'. Added a row number to the CTEs so i can match up the day & row_number to get you a set.
SELECT day
,array_to_string(array_agg(t.shift), ',') shifts
FROM (
WITH cte_start AS (
SELECT row_number() OVER (PARTITION BY day)
,day
,start_hour
FROM test22
WHERE start_hour <> '00:00:00'::time
)
,cte_stop AS (
SELECT row_number() OVER (PARTITION BY day)
,day
,stop_hour
FROM test22
WHERE stop_hour <> '00:00:00'::time
)
SELECT cte_start.day
,cte_start.start_hour::varchar || ' - ' || cte_stop.stop_hour::varchar AS shift
FROM cte_start
LEFT OUTER JOIN cte_stop ON cte_start.day = cte_stop.day
AND cte_start.row_number = cte_stop.row_number
) T
GROUP BY T.day
-HTH
Suppose I have a table with quantity column.
CREATE TABLE transfers (
user_id integer,
quantity integer,
created timestamp default now()
);
I'd like to iteratively go thru a partition using window functions, but access the output rows, not the input table rows.
To access the input table rows I could do something like this:
SELECT LAG(quantity, 1, 0)
OVER (PARTITION BY user_id ORDER BY created)
FROM transfers;
I need to access the previous output row to calculate the next output row. How can i access the lag row in the output? Something like:
CREATE VIEW balance AS
SELECT LAG(balance.total, 1, 0) + quantity AS total
OVER (PARTITION BY user_id ORDER BY created)
FROM transfers;
Edit
This is a minimal example to support the question of how to access the previous output row within a window partition. I don't actually want a sum.
It seems you attempt to calculate a running sum. Luckily that's just what Sum() window function does:
WITH transfers AS(
SELECT i, random()-0.3 AS quantity FROM generate_series(1,100) as i
)
SELECT i, quantity, sum(quantity) OVER (ORDER BY i) from transfers;
I guess, looking at the question, that the only you need is to calculate a cumulative sum.
To calculate a cumulative summ use this query:
SELECT *,
SUM( CASE WHEN quantity IS NULL THEN 0 ELSE quantity END)
OVER ( PARTITION BY user_id ORDER BY created
ROWS BETWEEN unbounded preceding AND current row
) As cumulative_sum
FROM transfers
ORDER BY user_id, created
;
But if you want more complex calculations, especially containing some conditions (decisions) that depend on a result from prevoius row, then you need a recursive approach.
So far I have come up with the below:
WHERE (extract(month FROM orders)) =
(SELECT min(extract(month from orderdate))
FROM orders)
However, that will consequently return zero to many rows, and in my case, many, because many orders exist within that same earliest (minimum) month, i.e. 4th February, 9th February, 15th Feb, ...
I know that a WHERE clause can contain multiple columns, so why wouldn't the below work?
WHERE (extract(day FROM orderdate)), (extract(month FROM orderdate)) =
(SELECT min(extract(day from orderdate)), min(extract(month FROM orderdate))
FROM orders)
I simply get: SQL Error: ORA-00920: invalid relational operator
Any help would be great, thank you!
Sample data:
02-Feb-2012
14-Feb-2012
22-Dec-2012
09-Feb-2013
18-Jul-2013
01-Jan-2014
Output:
02-Feb-2012
14-Feb-2012
Desired output:
02-Feb-2012
I recreated your table and found out you just messed up the brackets a bit. The following works for me:
where
(extract(day from OrderDate),extract(month from OrderDate))
=
(select
min(extract(day from OrderDate)),
min(extract(month from OrderDate))
from orders
)
Use something like this:
with cte1 as (
select
extract(month from OrderDate) date_month,
extract(day from OrderDate) date_day,
OrderNo
from tablename
), cte2 as (
select min(date_month) min_date_month, min(date_day) min_date_day
from cte1
)
select cte1.*
from cte1
where (date_month, date_day) = (select min_date_month, min_date_day from cte2)
A common table expression enables you to restructure your data and then use this data to do your select. The first cte-block (cte1) selects the month and the day for each of your table rows. Cte2 then selects min(month) and min(date). The last select then combines both ctes to select all rows from cte1 that have the desired month and day.
There is probably a shorter solution to that, however I like common table expressions as they are almost all the time better to understand than the "optimal, shortest" query.
If that is really what you want, as bizarre as it seems, then as a different approach you could forget the extracts and the subquery against the table to get the minimums, and use an analytic approach instead:
select orderdate
from (
select o.*,
row_number() over (order by to_char(orderdate, 'MMDD')) as rn
from orders o
)
where rn = 1;
ORDERDATE
---------
01-JAN-14
The row_number() effectively adds a pseudo-column to every row in your original table, based on the month and day in the order date. The rn values are unique, so there will be one row marked as 1, which will be from the earliest day in the earliest month. If you have multiple orders with the same day/month, say 01-Jan-2013 and 01-Jan-2014, then you'll still only get exactly one with rn = 1, but which is picked is indeterminate. You'd need to add further order by conditions to make it deterministic, but I have no idea what you might want.
That is done in the inner query; the outer query then filters so that only the records marked with rn = 1 is returned; so you get exactly one row back from the overall query.
This also avoids the situation where the earliest day number is not in the earliest month number - say if you only had 01-Jan-2014 and 02-Feb-2014; comparing the day and month separately would look for 01-Feb-2014, which doesn't exist.
SQL Fiddle (with Thomas Tschernich's anwer thrown in too, giving the same result for this data).
To join the result against your invoice table, you don't need to join to the orders table again - especially not with a cross join, which is skewing your results. You can do the join (at least) two ways:
SELECT
o.orderno,
to_char(o.orderdate, 'DD-MM-YYYY'),
i.invno
FROM
(
SELECT o.*,
row_number() over (order by to_char(orderdate, 'MMDD')) as rn
FROM orders o
) o, invoices i
WHERE i.invno = o.invno
AND rn = 1;
Or:
SELECT
o.orderno,
to_char(o.orderdate, 'DD-MM-YYYY'),
i.invno
FROM
(
SELECT orderno, orderdate, invno
FROM
(
SELECT o.*,
row_number() over (order by to_char(orderdate, 'MMDD')) as rn
FROM orders o
)
WHERE rn = 1
) o, invoices i
WHERE i.invno = o.invno;
The first looks like it does more work but the execution plans are the same.
SQL Fiddle with your pastebin-supplied query that gets two rows back, and these two that get one.
I need to update a column in a table to the latest date/time combination from another table. How can I get the latest date/time combination from the one table and then update a column with that date in another table?
The two tables I am using are called dbo.DD and dbo.PurchaseOrders. The JOIN between the two tables are dbo.DueDate.XDORD = dbo.PurchaseOrders.PBPO AND dbo.DueDate.XDLINE = dbo.PurchaseOrders.PBSEQ. The columns from dbo.DueDate that I need the latest date/time from are dbo.DueDate.XDCCTD and dbo.DueDate.XDCCTT.
I need to set dbo.PurchaseOrders.PBDUE = dbo.DueDate.XDCURDT.I can't use an ORDER BY statement in the UPDATE statement, so I'm not sure how to do this. I know row_number sometimes works in these situations, but I'm unsure of how to implement.
The general pattern is:
;WITH s AS
(
SELECT
key, -- may be multiple columns
date_col,
rn = ROW_NUMBER() OVER
(
PARTITION BY key -- again, may be multiple columns
ORDER BY date_col DESC
)
FROM dbo.SourceTable
)
UPDATE d
SET d.date_col = s.date_col
FROM dbo.DestinationTable AS d
INNER JOIN s
ON d.key = s.key -- one more time, may need multiple columns here
WHERE s.rn = 1;
I didn't try to map your table names and columns because (a) I didn't get from your word problem which table was the source and which was the destination and (b) those column names look like alphabet soup and I would have screwed them up anyway.
Did seem though that the OP got this specific code working:
;WITH s AS
(
SELECT
XDORD, XDLINE,
XDCURDT,
rn = ROW_NUMBER() OVER
(
PARTITION BY XDORD, XDLINE
ORDER BY XDCCTD DESC, XDCCTT desc
)
FROM dbo.DueDate
)
UPDATE d
SET d.PBDUE = s.XDCURDT
FROM dbo.PurchaseOrders AS d
INNER JOIN s
ON d.PBPO = s.XDORD AND d.PBSEQ = s.XDLINE
WHERE s.rn = 1;