Let's suppose I have this MySQL table:
id place_id area_mq n
-- -------- ------- --
1 1 50 1
2 2 90 1
3 2 20 1
4 3 10 1
5 3 10 2
6 3 10 3
7 4 20 1
8 4 20 2
9 5 15 1
10 5 25 1
id is the primary key, place_id stands for an area id, area_mq is the surface area of the place in mq.
What I have to do is find a compact query to calculate the sum of area_mq with these rules:
if n is equal for the same place_id, then count every area_mq (f.ex for place_id=2, I count 90 and 20 in the sum)
if n is different for the same place_id, then count area_mq only once (possible to do because for these kind of "places" the value will be the same; f.ex. place_id=4, there are two 20's, i sum only 20 and not 40).
In this example, my correct total would be: 50 + (90 + 20) + 10 + 20 + (15 + 25).
Can I accomplish this with a query (no code or procedures)? If requirements for n were reversed, it would be simple with a GROUP BY and a subquery... but with these conditions, I'm stuck.
select place_id, sum(area_sq)/count(distinct n)
from your_table
group by place_id;
Tested here
From what I see in your pattern all with n = 1 is added?
SELECT SUM((n = 1) * area_mq) AS total
FROM table_name
I do a validation that either returns 1 or 0, and then I multiply it with the column value.
I think you could use something like this. Take the sum and the count of n, and also the min and max (maybe overkill); use that to figure out if all values of n are the same. Along these lines:
SELECT
CASE WHEN sm/cnt = mn AND sm/cnt = mx THEN sum_area
ELSE area/cnt END
AS sum_area
FROM (
SELECT COUNT(n) cnt, SUM(n) sm, MIN(n) mn, MAX(n) mx, SUM(area_mq) sum_area
GROUP BY place_id
) a
So, say n has values of 2 and 2 => sm/cnt = mn (4/2 = 2) and mx. If it has values of 2 and 1 => sm/cnt != mn (3/2 != 1).
Related
I have a database with a table called BOOKINGS containing the following values
main-id place-id start-date end-date
1 1 2018-8-1 2018-8-8
2 2 2018-6-6 2018-6-9
3 3 2018-5-5 2018-5-8
4 4 2018-4-4 2018-4-5
5 5 2018-3-3 2018-3-10
5 1 2018-1-1 2018-1-6
4 2 2018-2-1 2018-2-10
3 3 2018-3-1 2018-3-28
2 4 2018-4-1 2018-4-6
1 5 2018-5-1 2018-5-15
1 3 2018-6-1 2018-8-8
1 4 2018-7-1 2018-7-6
1 1 2018-8-1 2018-8-18
1 2 2018-9-1 2018-9-3
1 5 2018-10-1 2018-10-6
2 5 2018-11-1 2018-11-5
2 3 2018-12-1 2018-12-25
2 2 2018-2-2 2018-2-19
2 4 2018-4-4 2018-4-9
2 1 2018-5-5 2018-5-23
What I need to do is for each main-id I need to find the largest total number of days for every place-id. Basically, I need to determine where each main-id has spend the most time.
This information must then be put into a view, so unfortunately I can't use temporary tables.
The query that gets me the closest is
CREATE VIEW `MOSTTIME` (`main-id`,`place-id`,`total`) AS
SELECT `BOOKINGS`.`main-id`, `BOOKINGS`.`place-id`, SUM(DATEDIFF(`end-date`, `begin-date`)) AS `total`
FROM `BOOKINGS`
GROUP BY `BOOKINGS`.`main-id`,`RESERVATION`.`place-id`
Which yields:
main-id place-id total
1 1 24
1 2 18
1 5 5
2 1 2
2 2 20
2 4 9
3 1 68
3 2 24
3 3 30
4 1 5
4 2 10
4 4 1
5 1 19
5 2 4
5 5 7
What I need is then the max total for each distinct main-id:
main-id place-id total
1 1 24
2 2 20
3 1 68
4 2 10
5 1 19
I've dug through a large amount of similar posts that recommend things like self joins; however, due to the fact that I have to create the new field total using an aggregate function (SUM) and another function (DATEDIFF) rather than just querying an existing field, my attempts at implementing those solutions have been unsuccessful.
I am hoping that my query that got me close will only require a small modification to get the correct solution.
Having hyphen character - in column name (which is also minus operator) is a really bad idea. Do consider replacing it with underscore character _.
One possible way is to use Derived Tables. One Derived Table is used to determine the total on a group of main id and place id. Another Derived Table is used to get maximum value out of them based on main id. We can then join back to get only the row corresponding to the maximum value.
CREATE VIEW `MOSTTIME` (`main-id`,`place-id`,`total`) AS
SELECT b1.main_id, b1.place_id, b1.total
FROM
(
SELECT `main-id` AS main_id,
`place-id` AS place_id,
SUM(DATEDIFF(`end-date`, `begin-date`)) AS total
FROM BOOKINGS
GROUP BY main_id, place_id
) AS b1
JOIN
(
SELECT dt.main_id, MAX(dt.total) AS max_total
FROM
(
SELECT `main-id` AS main_id,
`place-id` AS place_id,
SUM(DATEDIFF(`end-date`, `begin-date`)) AS total
FROM BOOKINGS
GROUP BY main_id, place_id
) AS dt
GROUP BY dt.main_id
) AS b2
ON b1.main_id = b2.main_id AND
b1.total = b2.max_total
MySQL 8+ solution would be utilizing the Row_Number() functionality:
CREATE VIEW `MOSTTIME` (`main-id`,`place-id`,`total`) AS
SELECT b.main_id, b.place_id, b.total
FROM
(
SELECT dt.main_id,
dt.place_id,
dt.total
ROW_NUMBER() OVER (PARTITION BY dt.main_id
ORDER BY dt.total DESC) AS row_num
FROM
(
SELECT `main-id` AS main_id,
`place-id` AS place_id,
SUM(DATEDIFF(`end-date`, `begin-date`)) AS total
FROM BOOKINGS
GROUP BY main_id, place_id
) AS dt
GROUP BY dt.main_id
) AS b
WHERE b.row_num = 1
I have a strange error first time seing such results maybe someone else also found how to overpass such odd error.
I have a table structure like this :
|id|uid|test1|test2|rid|
1 1 - - 1
2 1 - - 1
3 2 - - 2
4 2 - - 2
5 3 - - 3
6 3 - - 3
7 4 - - 4
8 4 - - 4
----------------------------
as "-" are varchar data all other columns are integers
My query with the odd results is this :
SELECT COUNT(uid) AS COUNT,
id AS ID,
uid AS InqID,
test1 AS A,
test2 AS B
FROM test_table
WHERE rid = (X)
GROUP BY uid
ORDER BY id DESC
As results i get
if (X) = 1 or 3 it shows me the correct last id number (2 id for 1 and 6 id for 3)
but if (X) is 2 or 4 it shows me the first in row id number (3 id for 2 instead of 4 and 7 id for 4 instead of 8)
Can anyone tell me why i get the correct results only as singles in rid and not at even numbers of rid column or how at least this query will work as it has to ?
Thank you all in advance
Use MAX(id) instead of ORDER BY.
SELECT COUNT(uid) AS COUNT, MAX(id) AS ID, uid AS InqID, test1 AS A, test2 AS B
FROM test_table
WHERE rid = (X)
GROUP BY uid
plz refer the table to provide the sql query to get result like that.
id value
1 10
2 15
3 30
4 10
5 11
6 12
Desired output:
id value
1 55
2 33
http://sqlfiddle.com/#!9/21cbc8
Divide id by 3, round it up, group it (with a sum):
SELECT
ceiling(id / 3) AS NewID,
sum(Value) AS SumValue
FROM MyTable
GROUP BY ceiling(id / 3)
With a variable:
SET #GroupVar = 3; -- Set this number to whatever you want to group by
SELECT
ceiling(id / #GroupVar) AS NewID,
sum(Value) AS SumValue
FROM MyTable
GROUP BY ceiling(id / #GroupVar);
I want to SUM two columns from two different database and output the highest value.
trying to figure it out since last 1day but no luck. can anyone please help?
Table 1
mid points
1 20
2 10
1 10
1 30
3 10
Table 2
mid points
1 20
2 10
1 10
2 20
1 10
3 10
so the total should be
mid points
1 100
2 40
3 20
output that i want highest total mid is 1 = 100
Try this untested query:
select mid , sum(points) from (
select mid,points from table1
union all
select mid,points from table2
) as table3
group by mid
order by sum(points) DESC
limit 1
I have a table of data like this:
id user_id A B C
=====================
1 15 1 2 3
2 15 1 2 5
3 20 1 3 9
4 20 1 3 7
I need to remove duplicate user ids and keep the record that sorts lowest when sorting by A then B then C. So using the above table, I set up a temp query (qry_temp) that simply does the sort--first on user_id, then on A, then on B, then on C. It returns the following:
id user_id A B C
====================
1 15 1 2 3
2 15 1 2 5
4 20 1 3 7
3 20 1 3 9
Then I wrote a Totals Query based on qry_temp that just had user_id (Group By) and then id (First), and I assumed this would return the following:
user_id id
===========
15 1
20 4
But it doesn't seem to do that--instead it appears to be just returning the lowest id in a group of duplicate user ids (so I get 1 and 3 instead of 1 and 4). Shouldn't the Totals query use the order of the query it's based upon? Is there a property setting in the query that might impact this or another way to get what I need? If it helps, here is the SQL:
SELECT qry_temp.user_id, First(qry_temp.ID) AS FirstOfID
FROM qry_temp
GROUP BY qry_temp.user_id;
You need a different type of query, for example:
SELECT tmp.id,
tmp.user_id,
tmp.a,
tmp.b,
tmp.c
FROM tmp
WHERE (( ( tmp.id ) IN (SELECT TOP 1 id
FROM tmp t
WHERE t.user_id = tmp.user_id
ORDER BY t.a,
t.b,
t.c,
t.id) ));
Where tmp is the name of your table. First, Last, Min and Max are not dependent on a sort order. In relational databases, sort orders are quite ephemeral.