I have the next query which does not work:
UPDATE item
SET popularity= (CASE
WHEN (select SUM(io.quantity) from item i NATURAL JOIN itemorder io GROUP BY io.item_id) > 3 THEN TRUE
ELSE FALSE
END);
Here I want to compare each line of inner SELECT SUM value with 3 and update popularity. But SQL gives error:
ERROR: more than one row returned by a subquery used as an expression
I understand that inner SELECT returns many values, but can smb help me in how to compare each line. In other words make loop.
When using a subquery you need to get a single row back, so you're effectively doing a query for each record in the item table.
UPDATE item i
SET popularity = (SELECT SUM(io.quantity) FROM itemorder io
WHERE io.item_id = i.item_id) > 3;
An alternative (which is a postgresql extension) is to use a derived table in a FROM clause.
UPDATE item i2
SET popularity = x.orders > 3
FROM (select i.item_id, SUM(io.quantity) as orders
from item i NATURAL JOIN itemorder io GROUP BY io.item_id)
as x(item_id,orders)
WHERE i2.item_id = x.item_id
Here you're doing a single group clause as you had, and we're joining the table to be updated with the results of the group.
Related
Goal: Create a query to pull the closest cycle count event (Table C) for a product ID based on the inventory adjustments results sourced from another table (Table A).
All records from Table A will be used, but is not guaranteed to have a match in Table C.
The ID column will be present in both tables, but is not unique in either, so that pair of IDs and Timestamps together are needed for each table.
Current simplified SQL
SELECT
A.WHENOCCURRED,
A.LPID,
A.ITEM,
A.ADJQTY,
C.WHENOCCURRED,
C.LPID,
C.LOCATION,
C.ITEM,
C.QUANTITY,
C.ENTQUANTITY
FROM
A
LEFT JOIN
C
ON A.LPID = C.LPID
WHERE
A.facility = 'FACID'
AND A.WHENOCCURRED > '23-DEC-22'
AND A.ADJREASONABBREV = 'CYCLE COUNTS'
ORDER BY A.WHENOCCURRED DESC
;
This is currently pulling the first hit on C.WHENOCCURRED on the LPID matches. Want to see if there is a simpler JOIN solution before going in a direction that creates 2 temp tables based on WHENOCCURRED.
I have a functioning INDEX(MATCH(MIN()) solution in Excel but that requires exporting a couple system reports first and is extremely slow with X,XXX row tables.
If you are using Oracle 12 or later, you can use a LATERAL join and FETCH FIRST ROW ONLY:
SELECT A.WHENOCCURRED,
A.LPID,
A.ITEM,
A.ADJQTY,
C.WHENOCCURRED,
C.LPID,
C.LOCATION,
C.ITEM,
C.QUANTITY,
C.ENTQUANTITY
FROM A
LEFT OUTER JOIN LATERAL (
SELECT *
FROM C
WHERE A.LPID = C.LPID
AND A.whenoccurred <= c.whenoccurred
ORDER BY c.whenoccurred
FETCH FIRST ROW ONLY
) C
ON (1 = 1) -- The join condition is inside the lateral join
WHERE A.facility = 'FACID'
AND A.WHENOCCURRED > DATE '2022-12-23'
AND A.ADJREASONABBREV = 'CYCLE COUNTS'
ORDER BY A.WHENOCCURRED DESC;
I am trying to map a certain value of a column based on its count on another table. If the count of [Location] i.e a column of IMPORT.DATA_SCRAP table in each row. For now for location static value i.e Utah and Kathmandu is supplied for test purpose only is equal to 1, then only i need to get the result in the select statement i.e only single value expression must be returned but here n rows of table with value is returned.
For. eg. In the below query,total rows of IMPORT.DATA_SCRAP gets returned, i only need the single first row value in my case.
I came to know whether cursor or CTE will acheive my result but i am unable to figure it out.
Here,
select
case
when
((SELECT COUNT(stateName) FROM Location.tblState where stateName = 'Utah')=1)
then (select stateName, CountryName from Location.tblState where stateName= 'Utah')
end as nameof
from IMPORT.DATA_SCRAP
The relation between country, state, city is as below:
select
case
when
((SELECT COUNT(cityName) FROM Location.tblCity where cityName = 'Kathmandu')=1)
then (select ct.countryName from Location.tblCity c
inner join Location.tblState s
on c.stateID = s.StateID
inner join Location.tblCountry ct
on ct.countryId = s.CountryId
where c.cityName = 'Kathmandu'
)
end as nameof
from IMPORT.DATA_SCRAP
How can i return only a single value expresion despite of multiple nmax rows of IMPORT.DATA_SCRAP row in the result.
If i comment out the -- from IMPORT.DATA_SCRAP in the above query i would get the desired single result expression in my case, but unable how can i acheive it in other ways or suggest me the appropriate way to do these types of situation.
I am looking to join three tables via ids, the outcome being three json columns with the content from each.
The issue I am facing is that for each cat_request there are many cat_request_fields, I am currently getting cat_request_fields as one object and not an array of objects.
This query gets me a result set with cat_requests and cat_request_fields.
SELECT
row_to_json("cat_requests") AS cat_request,
array_agg(row_to_json("cat_request_fields")) AS cat_request_fields
FROM
"cat_requests"
LEFT OUTER JOIN "cat_request_fields" ON "cat_requests"."id" = "cat_request_fields"."cat_request_id"
GROUP BY
"cat_requests"."id"
LIMIT 10;
This query gets me a result set with cats and cat_requests.
SELECT
row_to_json("cat_requests") as cat_request,
row_to_json("cats") as cat
FROM
"cat_requests",
"cats"
WHERE
"cat_requests"."cat_id" = "cats"."id"
LIMIT 1;
I'm looking for a query that will give me a combination of the two...
How can I modify this query to map the cat_request_fields to be an array of rows and not just one.
SELECT
row_to_json("cat_requests") AS cat_request,
(select row_to_json("cats".*) as cats from "cats" where "cats"."id" = "cat_requests"."cat_id"),
array_agg(row_to_json("cat_request_fields")) AS cat_request_fields
FROM
"cat_requests"
INNER JOIN "cat_request_fields" ON "cat_requests"."id" = "cat_request_fields"."cat_request_id"
GROUP BY
"cat_requests"."id"
LIMIT 6;
Why is it, that if you use jsonb_set as new values in an UPDATE query, that it only updates the first row of the result set?
See this example here: http://sqlfiddle.com/#!17/0bdd8/5
There are two entries in reactions for the same post, yet when I try to assign a random value keyed to the username, it only inserts it for the first value not for the second one:
UPDATE posts
SET a_to_b = jsonb_set(posts.a_to_b, array[username::text], to_jsonb(random()))
FROM reactions
WHERE posts.id = reactions.post_id;
There are more than one row in the FROM clause for a single row to be modified. The documentation explains it clearly:
When using FROM you should ensure that the join produces at most one output row for each row to be modified. In other words, a target row shouldn't join to more than one row from the other table(s). If it does, then only one of the join rows will be used to update the target row, but which one will be used is not readily predictable.
You can execute a single update by aggregating the expected value in a subquery. Use the aggregate function jsonb_object_agg():
update posts p
set a_to_b = agg
from (
select p.id, jsonb_object_agg(username, random()) as agg
from posts p
join reactions r on p.id = r.post_id
group by p.id
) s
where s.id = p.id;
SqlFiddle.
Alternatively, you can use an anonymous code block to repeatedly update a single row, e.g.:
do $$
declare rec record;
begin
for rec in
select *
from posts p
join reactions r on p.id = r.post_id
loop
update posts
set a_to_b = jsonb_set(a_to_b, array[rec.username], to_jsonb(random()))
where posts.id = rec.post_id;
end loop;
end $$;
The second solution may turn out to be suboptimal, especially for a large number of aggregated values.
I'm trying create a SELECT with GROUP BY in Firebird but I can't have any success. How could I do this ?
Exception
Can't format message 13:896 -- message file C:\firebird.msg not found.
Dynamic SQL Error.
SQL error code = -104.
Invalid expression in the select list (not contained in either an aggregate function or the GROUP BY clause).
(49,765 sec)
trying
SELECT FA_DATA, FA_CODALUNO, FA_MATERIA, FA_TURMA, FA_QTDFALTA,
ALU_CODIGO, ALU_NOME,
M_CODIGO, M_DESCRICAO,
FT_CODIGO, FT_ANOLETIVO, FT_TURMA
FROM FALTAS Falta
INNER JOIN ALUNOS Aluno ON (Falta.FA_CODALUNO = Aluno.ALU_CODIGO)
INNER JOIN MATERIAS Materia ON (Falta.FA_MATERIA = Materia.M_CODIGO)
INNER JOIN FORMACAOTURMAS Turma ON (Falta.FA_TURMA = Turma.FT_CODIGO)
WHERE (Falta.FA_CODALUNO = 238) AND (Turma.FT_ANOLETIVO = 2015)
GROUP BY Materia.M_CODIGO
Simple use of group by in firebird,group by all columns
select * from T1 t
where t.id in
(SELECT t.id FROM T1 t
INNER JOIN T2 j ON j.id = t.jid
WHERE t.id = 1
GROUP BY t.id)
Using GROUP BY doesn't make sense in your example code. It is only useful when using aggregate functions (+ some other minor uses). In any case, Firebird requires you to specify all columns from the SELECT column list except those with aggregate functions in the GROUP BY clause.
Note that this is more restrictive than the SQL standard, which allows you to leave out functionally dependent columns (ie if you specify a primary key or unique key, you don't need to specify the other columns of that table).
You don't specify why you want to group (because it doesn't make much sense to do it with this query). Maybe instead you want to ORDER BY, or you want the first row for each M_CODIGO.