I have table_1 with the following data:
| STORE | Add | dis | Cnt |
+-------+-----+-----+-----+
| 101 | X | abc | 2 |
| 101 | X | null| 3 |
| 101 | X |pqrd | 4 |
| 101 | X | null| 1 |
| 102 | y | null| 1 |
| 102 | y | xyz | 3 |
| 102 | y | pqr | 4 |
| 102 | y | null| 2 |
I tried to build a query to get data from table_1 where [dis] is not null and [cnt] should be minumum. So my result should looks like below:
| STORE | Add | dis | Cnt |
+-------+-----+-----+-----+
| 101 | X | abc | 2 |
| 102 | y | xyz | 3 |
My query looks like below :
SELECT store,add,dis,min(TMPLT_PRIORITY_NMBR)
FROM table_1 group by store,add;
But I get the following error:
Column 'dis' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.
If I use [dis] in GROUP BY clause, I get the wrong result and giving max(dis) or min(dis) also provides the wrong result.
What would be the solution for this issue?
You could use rank to find the row with the minimal cnt value per store/add combination, and return all the columns from it:
SELECT store, add, dis, cnt
FROM (SELECT *, RANK() OVER (PARTITION BY store, add ORDER BY cnt) AS rk
FROM table_1
WHERE dis IS NOT NULL) t
WHERE rk = 1
Another option would be to use first_value and min with over:
SELECT distinct store,
add,
first_value(dis) over(partition by store, add order by Cnt) as dis,
min(Cnt) over(partition by store, add) as cnt
FROM table_1
Related
Given a number of tables like the following, representing state-changes at time t of an entity identified by id:
| A | | B |
| t | id | a | | t | id | b |
| - | -- | - | | - | -- | - |
| 0 | 1 | 1 | | 0 | 1 | 3 |
| 1 | 1 | 2 | | 2 | 1 | 2 |
| 5 | 1 | 3 | | 3 | 1 | 1 |
where t is in reality a DateTime field with millisecond precision (making discretisation infeasible), how would I go about creating the following output?
| output |
| t | id | a | b |
| - | -- | - | - |
| 0 | 1 | 1 | 3 |
| 1 | 1 | 2 | 3 |
| 2 | 1 | 2 | 2 |
| 3 | 1 | 2 | 1 |
| 5 | 1 | 3 | 1 |
The idea is that for any given input timestamp, the entire state of a selected entity can be extracted by selecting one row from the resulting table. So the latest state of each variable corresponding to any time needs to be present in each row.
I've tried various JOIN statements, but I seem to be getting nowhere.
Note that in my use case:
rows also need to be joined by entity id
there may be more than two source tables to be merged
I'm running PostgreSQL, but I will eventually translate the query to SQLAlchemy, so a pure SQLAlchemy solution would be even better
I've created a db<>fiddle with the example data.
I think you want a full join and some other manipulations. The ideal would be:
select t, id,
last_value(a.a ignore nulls) over (partition by id order by t) as a,
last_value(b.b ignore nulls) over (partition by id order by t) as b
from a full join
b
using (t, id);
But . . . Postgres doesn't support ignore nulls. So an alternative method is:
select t, id,
max(a) over (partition by id, grp_a) as a,
max(b) over (partition by id, grp_b) as b
from (select *,
count(a.a) over (partition by id order by t) as grp_a,
count(b.b) over (partition by id order by t) as grp_b
from a full join
b
using (t, id)
) ab;
I would like to match any entries in a logs table which occurs having the same day and cause which are in the table more than once. I wrote the query for that fetches already the duplicates, my problem is that I need to have access to all the columns in the result from the table for later JOINs. Table looks like that:
| ID | DATE | CAUSE | USER | ... |
|--------------------------------------|
| x | 2017-01-01 | aaa | 100 | ... |
| x | 2017-01-02 | aaa | 101 | ... |
| x | 2017-01-03 | bbb | 101 | ... |
| x | 2017-01-03 | bbb | 101 | ... |
| x | 2017-01-04 | ccc | 101 | ... |
| x | 2017-01-04 | ccc | 101 | ... |
| x | 2017-01-04 | ccc | 101 | ... |
| x | 2017-01-05 | aaa | 101 | ... |
| .....................................|
| .....................................|
| .....................................|
Query:
SELECT logs.* FROM
(SELECT day, cause FROM logs
GROUP BY day, cause HAVING COUNT(*) > 1) AS logsTwice, logs
WHERE logsTwice.day = logs.day AND logsTwice.cause = logs.cause
The sub select fetches exactly the right data (date and cause) but when I try to get the additional columns of these matches I get completely wrong data. What am I doing wrong?
You can just use window functions:
SELECT l.*
FROM (SELECT l.*,
COUNT(*) OVER (PARTITION BY day, cause) as cnt
FROM logs l
) l
WHERE cnt > 1;
In general, window functions will have better performance than the equivalent query using JOIN and GROUP BY.
Try this:
SELECT logs.* FROM logs
inner join
(SELECT day, cause FROM logs GROUP BY day, cause HAVING COUNT(*) > 1) logsTwice
on logsTwice.day = logs.day AND logsTwice.cause = logs.cause
You can try
SELECT l1.*
FROM logs l1
INNER JOIN logs l2
ON (l1.id <> l2.id
AND l1.day = l2.day
AND l1.cause = l2.cause
AND l1.user <> l2.user);
I am trying my hardest to get a list of the most recent rows by date in a DB2 file. The file has no unique id, so I am trying to get the entries by matching a set of columns. I need DESCGA most importantly as that changes often. When it does they keep another row for historical reasons.
SELECT B.COGA, B.COMSUBGA, B.ACCTGA, B.PRFXGA, B.DESCGA
FROM mylib.myfile B
WHERE
(
SELECT COUNT(*)
FROM
(
SELECT A.COGA,A.COMSUBGA,A.ACCTGA,A.PRFXGA,MAX(A.DATEGA) AS EDATE
FROM mylib.myfile A
GROUP BY A.COGA, A.COMSUBGA, A.ACCTGA, A.PRFXGA
) T
WHERE
(B.ACCTGA = T.ACCTGA AND
B.COGA = T.COGA AND
B.COMSUBGA = T.COMSUBGA AND
B.PRFXGA = T.PRFXGA AND
B.DATEGA = T.EDATE)
) > 1
This is what I am trying and so far I get 0 results.
If I remove
B.ACCTGA = T.ACCTGA AND
It will return results (of course wrong).
I am using ODBC in VS 2013 to structure this query.
I have a table with the following
| a | b | descri | date |
-----------------------------
| 1 | 0 | string | 20140102 |
| 2 | 1 | string | 20140103 |
| 1 | 1 | string | 20140101 |
| 1 | 1 | string | 20150101 |
| 1 | 0 | string | 20150102 |
| 2 | 1 | string | 20150103 |
| 1 | 1 | string | 20150103 |
and i need
| 1 | 0 | string | 20150102 |
| 2 | 1 | string | 20150103 |
| 1 | 1 | string | 20150103 |
You can use row_number():
select t.*
from (select t.*,
row_number() over (partition by a, b order by date desc) as seqnum
from mylib.myfile t
) t
where seqnum = 1;
I would like to filter my table by MIN() function but still keep columns which cant be grouped.
I have table:
+----+----------+----------------------+
| ID | distance | geom |
+----+----------+----------------------+
| 1 | 2 | DSDGSAsd23423DSFF |
| 2 | 11.2 | SXSADVERG678BNDVS4 |
| 2 | 2 | XCZFETEFD567687SDF |
| 3 | 24 | SADASDSVG3423FD |
| 3 | 10 | SDFSDFSDF343DFDGF |
| 4 | 34 | SFDHGHJ546GHJHJHJ |
| 5 | 22 | SDFSGTHHGHGFHUKJYU45 |
| 6 | 78 | SDFDGDHKIKUI45 |
| 6 | 15 | DSGDHHJGHJKHGKHJKJ65 |
+----+----------+----------------------+
This is what I would like to achieve:
+----+----------+----------------------+
| ID | distance | geom |
+----+----------+----------------------+
| 1 | 2 | DSDGSAsd23423DSFF |
| 2 | 2 | XCZFETEFD567687SDF |
| 3 | 10 | SDFSDFSDF343DFDGF |
| 4 | 34 | SFDHGHJ546GHJHJHJ |
| 5 | 22 | SDFSGTHHGHGFHUKJYU45 |
| 6 | 15 | DSGDHHJGHJKHGKHJKJ65 |
+----+----------+----------------------+
it is possible when I use MIN() on distance column and grouping by ID but then I loose my geom which is essential.
The query looks like this:
SELECT "ID", MIN(distance) AS distance FROM somefile GROUP BY "ID"
the result is:
+----+----------+
| ID | distance |
+----+----------+
| 1 | 2 |
| 2 | 2 |
| 3 | 10 |
| 4 | 34 |
| 5 | 22 |
| 6 | 15 |
+----+----------+
but this is not what I want.
Any suggestions?
One common approach to this is to find the minimum values in a derived table that you join with:
SELECT somefile."ID", somefile.distance, somefile.geom
FROM somefile
JOIN (
SELECT "ID", MIN(distance) AS distance FROM somefile GROUP BY "ID"
) t ON t.distance = somefile.distance AND t.ID = somefile.ID;
Sample SQL Fiddle
You need a window function to do this:
SELECT "ID", distance, geom
FROM (
SELECT "ID", distance, geom, rank() OVER (PARTITION BY "ID" ORDER BY distance) AS rnk
FROM somefile) sub
WHERE rnk = 1;
This effectively orders the entire set of rows first by the "ID" value, then by the distance and returns the record for each "ID" where the distance is minimal - no need to do a GROUP BY.
select a.*,b.geom from
(SELECT ID, MIN(distance) AS distance FROM somefile GROUP BY ID) as a
inner join somefile as b on a.id=b.id and a.distance=b.distance
You can use "distinct on" clause of the PostgreSQL.
select distinct on(id) id, distance, geom
from table_name
order by distance;
I think this is what you are exactly looking for.
For more details on how "distinct on" works, refer the documentation and the example.
But, remember, using "distinct on" does not comply to SQL standards.
I have a table like:
| ID | Val |
+-------+-----+
| abc-1 | 10 |
| abc-2 | 30 |
| cde-1 | 10 |
| cde-2 | 10 |
| efg-1 | 20 |
| efg-2 | 11 |
and would like to get the result based on the substring(ID, 1, 3) and minimum value and ist must be only the first in case the Val has duplicates
| ID | Val |
+-------+-----+
| abc-1 | 10 |
| cde-1 | 10 |
| efg-2 | 11 |
the problem is that I am stuck, because I cannot use group by substring(id,1,3), ID since it will then have again 2 rows (each for abc-1 and abc-2)
WITH
sorted
AS
(
SELECT
*,
ROW_NUMBER() OVER (PARTITION BY substring(id,1,3) ORDER BY val, id) AS sequence_id
FROM
yourTable
)
SELECT
*
FROM
sorted
WHERE
sequence_id = 1
SELECT SUBSTRING(id,1,3),MIN(val) FROM Table1 GROUP BY SUBSTRING(id,1,3);
You were grouping the columns using both SUBSTRING(id,1,3),id instead of just SUBSTRING(id,1,3). It works perfectly fine.Check the same example in this below link.
http://sqlfiddle.com/#!3/fd9fc/1