I have a table like this one:
+----+---------+----------+
| id | group | value |
+----+---------+----------+
| 1 | GROUP A | 0.641028 |
| 2 | GROUP B | 0.946927 |
| 3 | GROUP A | 0.811552 |
| 4 | GROUP C | 0.216978 |
| 5 | GROUP A | 0.650232 |
+----+---------+----------+
If I perform the following query:
SELECT `id`, SUM(`value`) AS `sum` FROM `test` GROUP BY `group`;
I, obviously, get:
+----+-------------------+
| id | sum |
+----+-------------------+
| 1 | 2.10281205177307 |
| 2 | 0.946927309036255 |
| 4 | 0.216977506875992 |
+----+-------------------+
But I need a table like this one:
+----+-------------------+
| id | sum |
+----+-------------------+
| 1 | 2.10281205177307 |
| 2 | 0.946927309036255 |
| 3 | 2.10281205177307 |
| 4 | 0.216977506875992 |
| 5 | 2.10281205177307 |
+----+-------------------+
Where summed rows are explicitly repeated.
Is there a way to obtain this result without using multiple (nested) queries?
IT would depend on your SQL server, in Postgres/Oracle I'd use Window Functions. In MySQL... not possible afaik.
Perhaps you can fake it like this:
SELECT a.id, SUM(b.value) AS `sum`
FROM test AS a
JOIN test AS b ON a.`group` = b.`group`
GROUP BY a.id, b.`group`;
No there isn't AFAIK. You will have to use a join like
SELECT t.`id`, tsum.sum AS `sum`
FROM `test` as t GROUP BY `group`
JOIN (SELECT `id`, SUM(`value`) AS `sum` FROM `test` GROUP BY `group`) AS tsum
ON tsum.id = t.id
Related
I have a simple Entity-Attribute table in my database describing simply if an Entity has some Attribute by the existance of a row consisting of (Entity, Attribute).
I want to find out, of all the Entities with two and only two Attributes, what are the most common Attribute pairs
For example, if my table looked like:
+--------+-----------+
| Entity | Attribute |
+--------+-----------+
| Bob | A |
| Sally | B |
| Terry | C |
| Bob | B |
| Sally | A |
| Terry | D |
| Larry | C |
+--------+-----------+
I would want it to return
+-------------+-------------+-------+
| Attribute-1 | Attribute-2 | Count |
+-------------+-------------+-------+
| A | B | 2 |
| C | D | 1 |
+-------------+-------------+-------+
I currently have a short query that looks like:
WITH TwoAtts (
SELECT entity
FROM table
GROUP BY entity
HAVING COUNT(att) = 2
)
SELECT t1.att, t2.att, COUNT(entity)
FROM table t1
JOIN table t2
ON t1.entity = t2.entity
WHERE t1.entity IN (SELECT * FROM TwoAtts)
AND t1.att != t2.att
GROUP BY t1.att, t2.att
ORDER BY COUNT(entity) DESC
but is only capable of producing "duplicate" results like
+-------------+-------------+-------+
| Attribute-1 | Attribute-2 | Count |
+-------------+-------------+-------+
| A | B | 2 |
| B | A | 2 |
| D | C | 1 |
| C | D | 1 |
+-------------+-------------+-------+
In a sense I would like to be able to run a unordered DISTINCT / set operator over the two attribute columns, but I am not sure how to acheive this functionality in SQL?
Hmmm, I think you want two levels of aggregation, with some filtering:
select attribute_1, attribute_2, count(*)
from (select min(ea.attribute) as attribute_1, max(ea.attribute) as attribute_2
from entity_attribute ea
group by entity
having count(*) = 2
) aa
group by attribute_1, attribute_2;
Here is a db<>fiddle
How do I correctly join a table on two columns. My issue is that the result is not correct as it only joins on a single column.
This question started of in this other question: SQL query returns product of results instead of sum . I am creating a new question as there is an other issue I am trying to solve.
I join a table of materials on a table which contains multiple supply and disposal movements. Each movement references a material id. I would like to join the material on each movement.
My query:
SELECT supply_material_refer, disposal_material_refer, material_id, material_name
FROM "construction_sites"
JOIN projects ON construction_sites.project_refer = projects.project_id
JOIN addresses ON construction_sites.address_refer = addresses.address_id
cross join lateral ( select *
from (select row_number() over () as rn, *
from supplies
where supplies.supply_project_refer = projects.project_id) as supplies
full join (select row_number() over () as rn, *
from disposals
where disposals.disposal_project_refer = projects.project_id
) as disposals
on (supplies.rn = disposals.rn)
) as combined
LEFT JOIN materials material ON combined.disposal_material_refer = material.material_id
OR combined.supply_material_refer = material.material_id
WHERE (projects.project_name = 'Project 15')
ORDER BY construction_site_id asc;
The result of the query:
+-----------------------+-------------------------+-------------+---------------+
| supply_material_refer | disposal_material_refer | material_id | material_name |
+-----------------------+-------------------------+-------------+---------------+
| 1 | 1 | 1 | Materialtest |
| 2 | 1 | 1 | Materialtest |
| 2 | 1 | 2 | Dirt |
| 1 | 1 | 1 | Materialtest |
| 2 | 1 | 1 | Materialtest |
| 2 | 1 | 2 | Dirt |
| 1 | (null) | 1 | Materialtest |
| 4 | (null) | 4 | Stones |
+-----------------------+-------------------------+-------------+---------------+
An example line I have issues with:
+------------------------+-------------------------+-------------+---------------+
| supply_material_refer | disposal_material_refer | material_id | material_name |
+------------------------+-------------------------+-------------+---------------+
| 2 | 1 | 1 | Materialtest |
+------------------------+-------------------------+-------------+---------------+
A prefered output would be like:
+------------------------+----------------------+-------------------------+------------------------+
| supply_material_refer | supply_material_name | disposal_material_refer | disposal_material_name |
+------------------------+----------------------+-------------------------+------------------------+
| 2 | Dirt | 1 | Materialtest |
+------------------------+----------------------+-------------------------+------------------------+
I have created a sqlfiddle with dummy data: http://www.sqlfiddle.com/#!17/863d78/2
To my understanding the solution would be to have a disposal_material column and and supply_material column for the material names. I do not know how I can achieve this goal though...
Thanks for any help!
Given this table I want to retrieve for each different url the row with the maximum count. For this table the output should be: 'dell.html' 3, 'lenovo.html' 4, 'toshiba.html' 5
+----------------+-------+
| url | count |
+----------------+-------+
| 'dell.html' | 1 |
| 'dell.html' | 2 |
| 'dell.html' | 3 |
| 'lenovo.html' | 1 |
| 'lenovo.html' | 2 |
| 'lenovo.html' | 3 |
| 'lenovo.html' | 4 |
| 'toshiba.html' | 1 |
| 'toshiba.html' | 2 |
| 'toshiba.html' | 3 |
| 'toshiba.html' | 4 |
| 'toshiba.html' | 5 |
+----------------+-------+
What SQL query do I need to write to do this?
Try to use this query:
select url, max(count) as count
from table_name
group by url;
use aggregate function
select max(count) ,url from table_name group by url
From your comments it seems you need corelated subquery
select t1.* from table_name t1
where t1.count = (select max(count) from table_name t2 where t2.url=t1.url
)
If row_number support on yours sqllite version
then you can write query like below
select * from
(
select *,row_number() over(partition by url order by count desc) rn
from table_name
) a where a.rn=1
I have two tables in Access, Table A and Table B:
Table MasterLockInsNew:
+----+-------+----------+
| ID | Value | Date |
+----+-------+----------+
| 1 | 123 | 12/02/13 |
| 2 | 1231 | 11/02/13 |
| 4 | 1265 | 16/02/13 |
+----+-------+----------+
Table InitialPolData:
+----+-------+----------+---+
| ID | Value | Date |Type
+----+-------+----------+---+
| 1 | 123 | 12/02/13 | x |
| 2 | 1231 | 11/02/13 | x |
| 3 | 1238 | 10/02/13 | y |
| 4 | 1265 | 16/02/13 | a |
| 7 | 7649 | 18/02/13 | z |
+----+-------+----------+---+
All I want are the rows from table B for IDs not contained in A. My current code looks like this:
SELECT Distinct InitialPolData.*
FROM InitialPolData
WHERE InitialPolData.ID NOT IN (SELECT Distinct InitialPolData.ID
from InitialPolData INNER JOIN
MasterLockInsNew
ON InitialPolData.ID=MasterLockInsNew.ID);
But whenever I run this in Access it crashes!! The tables are fairly large but I don't think this is the reason.
Can anyone help?
Thanks
or try a left outer join:
SELECT b.*
FROM InitialPolData b left outer join
MasterLockInsNew a on
b.id = a.id
where
a.id is null
Simple subquery will do.
select * from InitialPolData
where id not in (
select id from MasterLockInsNew
);
Try using NOT EXISTS:
SELECT Distinct i.*
FROM InitialPolData AS i
WHERE NOT EXISTS (SELECT 1
FROM MasterLockInsNew AS m
WHERE m.ID = i.ID)
I have two tables, post_categories and posts. I'm trying to select * from post_categories;, but also return a temporary column with the count for each time a post category is used on a post.
Posts
| id | name | post_category_id |
| 1 | test | 1 |
| 2 | nest | 1 |
| 3 | vest | 2 |
| 4 | zest | 3 |
Post Categories
| id | name |
| 1 | cat_1 |
| 2 | cat_2 |
| 3 | cat_3 |
Basically, I'm trying to do this without subqueries and with joins instead. Something like this, but in real psql.
select * from post_categories some-type-of-join posts, count(*)
Resulting in this, ideally.
| id | name | count |
| 1 | cat_1 | 2 |
| 2 | cat_2 | 1 |
| 3 | cat_3 | 1 |
Your help is greatly appreciated :D
You can use a derived table that contains the counts per post_category_id and left join it to the post_categories table
select p.*, coalesce(t1.p_count,0)
from post_categories p
left join (
select post_category_id, count(*) p_count
from posts
group by post_category_id
) t1 on t1.post_category_id = p.id
select post_categories.id, post_categories.name , count(posts.id)
from post_categories
inner join posts
on post_category_id = post_categories.id
group by post_categories.id, post_categories.name