I have this table that is already sorted but I want it to only display the maximum values... so instead of this table:
+------+-------+
| id | value |
+------+-------+
| 1 | 3 |
| 5 | 3 |
| 4 | 3 |
| 9 | 2 |
| 8 | 2 |
| 3 | 2 |
| 2 | 1 |
| 6 | 1 |
| 7 | 1 |
+------+-------+
I want this:
+------+-------+
| id | value |
+------+-------+
| 1 | 3 |
| 5 | 3 |
| 4 | 3 |
+------+-------+
I'm using SQLite. thanks for any help.
You can do this using a subquery. Here is one way:
select t.*
from t
where t.value = (select max(value) from t);
Related
Hi i have a table like this;
+----+----------+-------------+
| id | room_id | house_id |
+----+----------+-------------+
| 1 | 1 | 1 |
| 2 | 2 | 1 |
| 3 | 3 | 1 |
| 4 | 1 | 2 |
| 5 | 2 | 2 |
| 6 | 3 | 2 |
| 7 | 1 | 3 |
| 8 | 2 | 3 |
| 9 | 3 | 3 |
+----+-------+----------------+
and i want to create a view like this
+----+----------+-------------+
| id | house_id | rooms |
+----+----------+-------------+
| 1 | 1 | [1,2,3] |
| 2 | 2 | [1,2,3] |
| 3 | 3 | [1,2,3] |
+----+-------+----------------+
i tried many ways but i cant gruop them in one line
Thanks for any help.
You can use array_agg():
select house_id, array_agg(room_id order by room_id) as rooms
from t
group by house_id;
If you want the first column to be incremental, you can use row_number():
select row_number() over (order by house_id) as id, . . .
So I have an accounts table in witch row may or may not have a parent account (0 means it doesn't have a parent):
+----+-----------+
| id | parent_id |
+----+-----------+
| 1 | 2 |
| 2 | 0 |
| 3 | 1 |
| 4 | 3 |
| 5 | 4 |
+----+-----------+
I was trying to add the top 3 parents for each row, so I would get something like this:
+----+-----------+----------+----------+----------+
| id | parent_id | parent_1 | parent_2 | parent_3 |
+----+-----------+----------+----------+----------+
| 1 | 2 | 2 | null | null |
| 2 | 0 | null | null | null |
| 3 | 1 | 2 | 1 | null |
| 4 | 3 | 2 | 1 | 3 |
| 5 | 4 | 2 | 1 | 3 |
+----+-----------+----------+----------+----------+
I figured I can do it with recursive queries, but I haven't managed to build a working query.
Any help would be appreciated.
Is there a way, in SQL, to create an Id for 'linked groups'?
Source Table
+----+-----+
| Id | Id |
+----+-----+
| 1 | 2 |
| 1 | 3 |
| 2 | 3 |
| 4 | 5 |
+----+-----+
Desired Result Table
+----+-----+-----------+
| Id | Id | Group Id |
+----+-----+-----------+
| 1 | 2 | A |
| 1 | 3 | A |
| 2 | 3 | A |
| 4 | 5 | B |
+----+-----+-----------+
see Diagram
I have two tables, A and B, and a join table M. I want to, for each A.id, get the top 2 B.id's sorting on the value in table M, producing the results below. This is running on an Azure SQL database
Table A Table M Table B
+-----+ +-----+-----+-------+ +-----+
| Id | | AId | BId | Value | | Id |
+-----+ +-----+-----+-------+ +-----+
| 1 | | 1 | 3 | 4 | | 1 |
| 2 | | 1 | 2 | 3 | | 2 |
| 3 | | 3 | 2 | 3 | | 3 |
| 4 | | 3 | 5 | 6 | | 4 |
+-----+ | 3 | 3 | 4 | | 5 |
| 4 | 1 | 2 | +-----+
| 4 | 2 | 1 |
| 4 | 4 | 3 |
+-----+-----+-------+
Result
+-----+-----+-------+
| AId | BId | Value |
+-----+-----+-------+
| 1 | 3 | 4 |
| 1 | 2 | 3 |
| 3 | 5 | 6 |
| 3 | 3 | 4 |
| 4 | 1 | 2 |
| 4 | 4 | 3 |
+-----+-----+-------+
I know that I can select all the M.AId rows where they equal 1, sort it, and limit by 2, but I need to do this for every row in Table A. I've made an attempt to use group by, but I wasn't sure how to sort and limit it. I've also tried to search for resources associated with this issue but I couldn't find any resources.
(I also wasn't sure how to word the title for this issue)
You can just use ROW_NUMBER:
SELECT
AId, BId, Value
FROM (
SELECT *,
Rn = ROW_NUMBER() OVER(PARTITION BY AId ORDER BY Value DESC)
FROM M
) t
WHERE Rn <= 2
i have table like this:
| ID | id_number | a | b |
| 1 | 1 | 0 | 215 |
| 2 | 2 | 28 | 8952 |
| 3 | 3 | 10 | 2000 |
| 4 | 1 | 0 | 215 |
| 5 | 1 | 0 |10000 |
| 6 | 3 | 10 | 5000 |
| 7 | 2 | 3 |90933 |
I want to sum a*b where id_number is same, what the query to get all value for every id_number? for example the result is like this :
| ID | id_number | result |
| 1 | 1 | 0 |
| 2 | 2 | 523455 |
| 3 | 3 | 70000 |
This is a simple aggregation query:
select id_number, sum(a*b)
from t
group by id_number
I'm not sure what the first column is for.