Select nearest date in the interval - mysql

I'm trying to select rows in which 3+ posts is in the interval 14 days.
For example:
User | id_post | date
1 | 12 | 2018-01-01
1 | 13 | 2018-01-05
1 | 14 | 2018-01-21
1 | 15 | 2018-01-27
1 | 16 | 2018-01-29
2 | 17 | 2018-01-01
2 | 18 | 2018-01-20
2 | 19 | 2018-02-17
2 | 20 | 2018-03-07
2 | 21 | 2018-04-29
User = OwnerUserId
date = CreationDate
In this case I need to return just User 1 because he has posts which are in 14 days.
Please, help me how I can get it. Thank you
Update: A user should have posts which were published in the interval of 14 days. It can be more, for example if the last day is in 2019 but in 2018 there was 3posts published within 14 days - it's ok
now i have (data get from data.stackexchange stackoverflow) and tried to apply
select OwnerUserId from Posts as p
where OwnerUserId in (select Users.id from Users WHERE YEAR (Users.CreationDate) >= 2017)
AND YEAR (p.CreationDate) >= 2018
AND p.Tags like '%sql%'
join (select OwnerUserId, CreationDate as startdate, dateadd(day,14,CreationDate) as enddate
from Posts) as r
on p.OwnerUserId = r.OwnerUserId and p.CreationDate between r.startdate and r.enddate
group by p.OwnerUserId, CreationDate
having count(*) >= 3
but it replies
Incorrect syntax near the keyword 'join'.
Incorrect syntax near the keyword 'as'.
I'm a begginner here and in the sql, so i dont exactly know how to combine my previous 'filtr' and current join with date

I'll not tell you the solution, but give you some pseudo-code and you figure out how to code it in SQL-
a) You should restrict your data for just 14 days.
b) Now, make groupings by User and find the count of records/lines present (for each User).
c) Now, again do a filter check to find users whose count of records is greater than 3.
Now, tell us which SQL keywords will be used for each points above.

I think something like
select p.user_id
from posts p
join (select user_id, xdate start_date, date_add(xdate, interval 14 day) end_date
from posts) r
on p.user_id = r.user_id and p.xdate between r.start_date and r.end_date
group by user_id, start_date
having count(*) >= 3
can help. It may not be the best possible solution, but it works.
Check it on SQL Fiddle

If you just want to select users by id you may try
Select id_post, date from yourtable where user = 2 order by id DESC limit 10;
You should have Colum called id with auto increment so new posts will have higher id so when it's sorted in descending it will start with post with higher id also you should have index on that id colum auto increment and index
If you don't want to use the above method then you will do that with date range like this
$date = gmdate() - (3600*24); 24 is 24 hours past
Select id_post, title from mutable where add_date > 'value of $date'
In both cases you should have index on user id
The second query is what you need but you should get the date from the equation first then apply it to the query

First, I think you mean user 1 not 2.
In MySQL 8+, this is pretty easy. If you want the first such post:
select t.*
from (select t.*,
lead(date, 2) over (partition by user order by date) as next_date2
from t
) t
where next_date2 <= date + interval 14 day;

Related

SQL consecutive occurrences for availability based query

I am a bit stuck trying to create a pretty complex on SQL, and more specifically MySQL.
The database deals with car rentals, and the main table of what is a snowflake patters looks a bit like:
id | rent_start | rent_duration | rent_end | customerID | carId
-----------------------------------------------------------------------------------
203 | 2016-10-03 | 5 | 2016-11-07 | 16545 | 4543
125 | 2016-10-20 | 9 | 2016-10-28 | 54452 | 5465
405 | 2016-11-01 | 2 | 2016-01-02 | 43565 | 346
My goal is to create a query that allows given
1) A period range like, for example: from 2016-10-03 to 2016-11-03
2) A number of days, for example: 10
allows me to retrieve the cars that are actually available for at least 10 CONSECUTIVE days between the 10th of October and the 11th.
A list of IDs for those cars is more than enough... I just don't really know how to setup a query like that.
If it can help: I do have a list of all the car IDs in another table.
Either way, thanks!
I think it is much simpler to work with availability, rather than rentals, for this purpose.
So:
select r.car_id, r.rent_end as avail_start,
(select min(r2.rent_start
from rentals r2
where r2.car_id = r.car_id and r2.rent_start > r.rent_start
) as avail_end
from rentals r;
Then, for your query, you need at least 10 days. You can use a having clause or subquery for that purpose:
select r.*
from (select r.car_id, r.rent_end as avail_start,
(select min(r2.rent_start
from rentals r2
where r2.car_id = r.car_id and r2.rent_start > r.rent_start
) as avail_end
from rentals r
) r
where datediff(avail_end, avail_start) >= $days;
And finally, you need for that period to be during the dates you specify:
select r.*
from (select r.car_id, r.rent_end as avail_start,
(select min(r2.rent_start
from rentals r2
where r2.car_id = r.car_id and r2.rent_start > r.rent_start
) as avail_end
from rentals r
) r
where datediff(avail_end, avail_start) >= $days and
( (avail_end > $end and avail_start < $start) or
(avail_start <= $start and avail_end >= $start + interval 10 day) or
(avail_start > $start and avail_start + interval 10 day <= $end)
);
This handles the various conditions where the free period covers the entire range or starts/ends during the range.
There are no doubt off-by-one errors in this logic (is a car available the same date it returns). The this should give you a solid approach for solving the problem.
By the way, you should also include cars that have never been rented. But that is not possible with the tables you describe in the question.

Mysql Unique records, where multiple records exist

I am struggling with a Mysql call and was hoping to borrow your expertise.
I believe that what I want may only be possible using two selects and I have not yet done one of these and am struggling to wrap my head around this.
I have a table like so:
+------------------+----------------------+-------------------------------+
| username | acctstarttime | acctstoptime |
+------------------+----------------------+-------------------------------+
| bill | 22.04.2014 | 23.04.2014 |
+------------------+----------------------+-------------------------------+
| steve | 16.09.2014 | |
+------------------+----------------------+-------------------------------+
| fred | 12.08.2014 | |
+------------------+----------------------+-------------------------------+
| bill | 24.04.2014 | |
+------------------+----------------------+-------------------------------+
I wish to select only unique records from the username column ie I only want one record for bill and I need the one with most recent start_date, providing they were weren't in the last three months (end_date is not important to me here) else I do not want any data. In summary I just need anyone where there most recent start date is over 3 months old.
The command I am using currently is:
SELECT DISTINCT(username), ra.acctstarttime AS 'Last IP', ra.acctstoptime
FROM radacct AS ra
WHERE ra.acctstarttime < DATE_SUB(now(), interval 3 month)
GROUP BY ra.username
ORDER BY ra.acctstarttime DESC
However, this simply gives me details about the date_start for that particular customer where they had a start date over 3 months ago.
I have tired a few other combinations of this and have tried a command with a double select but I'm currently hitting brick walls. Any help or a push in the right direction would be much appreciated.
Update
I have created the following:
http://sqlfiddle.com/#!2/f47b2/1
Effectively I should only see 1 row when the query is as it should be. This would be the row for bill. As he is the only one that does not have a start date within the last three months. The result I would expect to see is the following:
24 bill April, 11 2014 12:11:40+0000 (null)
As this is the latest start date for bill, but this start date is not within the last three months. Hopefully this will help clarify. Many thanks for your help thus far.
http://sqlfiddle.com/#!2/f47b2/14
This is another example. If the acctstartdate for bill would show as the April entry, then I could add my where clause for the last three months and this would give me my desired result.
SQLFiddle
http://sqlfiddle.com/#!2/444432/9 (MySQL 5.5)
I am looking at the question in 2 ways based on the current text:
I only want one record for bill and I need the one with most recent start_date, providing they were in the last three months (end_date is not important to me here) else I do not want any data
Structure
create table test
(
username varchar(20),
date_start date
);
Data
Username date_start
--------- -----------
bill 2014-09-25
bill 2014-09-22
bill 2014-05-26
andy 2014-05-26
tim 2014-09-25
tim 2014-05-26
What we want
Username date_start
--------- -----------
bill 2014-09-25
tim 2014-09-25
Query
select *
from test a
inner join
(
select username, max(date_start) as max_date_start
from test
where date_start > date_sub(now(), interval 3 month)
group by username
) b
on
a.username = b.username
and a.date_start = b.max_date_start
where
date_start > date_sub(now(), interval 3 month)
Explanation
For the most recent last 3 months, let's get maximum start date for each user. To limit the records to the latest 3 months we use where date_start > date_sub(now(), interval 3 month) and to find the maximum start date for each user we use group by username.
We, then, join main data with this small subset based on user and max date to get the desired result.
Another angle
If we desire to NOT look at the latest 3 months and instead find the most recent date for each user, we would be looking at this kind of data:
What we want
Username date_start
--------- -----------
bill 2014-05-26
tim 2014-05-26
andy 2014-05-26
Query
select *
from test a
inner join
(
select username, max(date_start) as max_date_start
from test
where date_start < date_sub(now(), interval 3 month)
group by username
) b
on
a.username = b.username
and a.date_start = b.max_date_start
where
date_start < date_sub(now(), interval 3 month)
Hopefully you can change these queries to your liking.
EDIT
Based on your good explanation, here's the query
SQLFiddle: http://sqlfiddle.com/#!2/f47b2/17
select *
from activity a
-- find max dates for users for records with dates after 3 months
inner join
(
select username, max(acctstarttime) as max_date_start
from activity
where acctstarttime < date_sub(now(), interval 3 month)
group by username
) b
on
a.username = b.username
and a.acctstarttime = b.max_date_start
-- find usernames who have data in the recent three months
left join
(
select username, count(*)
from activity
where acctstarttime >= date_sub(now(), interval 3 month)
group by username
) c
on
a.username = c.username
where
acctstarttime < date_sub(now(), interval 3 month)
-- choose users who DONT have data from recent 3 months
and c.username is null
Let me know if you would like me to add explanation
Try this:
select t.*
from radacct t
join (
select ra.username, max(ra.acctstarttime) as acctstarttime
from radacct as ra
WHERE ra.acctstarttime < DATE_SUB(now(), interval 3 month)
) s on t.username = s.username and t.acctstarttime = s.acctstarttime
SQLFiddle

MySQL: query with condition on one-to-many table

I have a table with schema like this:
clients_actions
id | client_id | action | date_done
1 | 1 | ... | 1394785392
2 | 2 | ... | 1394786392
3 | 2 | ... | 1394787392
date_done can be set both in the past, and in the future from current unix timestamp. I need to select all 'forgotten' clients, which don't have date_done set in future (in all his actions) and last his action is older than 604800 seconds (7 days). Client can have many actions. And also, if it's possible, I need in the same query to select his last action (which is in past and more than 7 days old).
How can it be done?
One way to do it as
select * from clients_actions
where from_unixtime(date_done) < date_sub(now(),INTERVAL 7 day)
AND client_id
NOT IN
(
select client_id from
clients_actions
where from_unixtime(date_done) > now()
)
;
DEMO
In the demo I have added some data with future dates so that they can be ignored and just by getting data older than 7 days. You can do group by in case there are repeated data in your table.
Select client_id, action, MAX(date_done) from clients_actions
WHERE date_done < (UNIX_TIMESTAMP(SYSDATE() - 7)
AND id NOT IN (SELECT id FROM clients_actions
WHERE date_done > (UNIX_TIMESTAMP(SYSDATE()))
GROUP BY client_id;
For the first part you want a query that has Where date_done < SysDate - 7 days and client_id not in (select id from clients_actions where date_done > SysDate (also converted to UNIX). This says I want all records whose date_done is older than 7 days ago, but that don't have any actions due in the future.
the MAX and group by client_id limit it to only the latest record of those selected by client_id.
The following query will get you the desired result.
SELECT *
FROM clients_actions ca
INNER JOIN
(SELECT client_id, MAX(date_done) as date_done
FROM clients_actions
WHERE DATEDIFF(CURRENT_TIMESTAMP, FROM_UNIXTIME(date_done)) >= 7
GROUP BY client_id) latest_date
ON ca.client_id = latest_date.client_id AND ca.date_done = latest_date.date_done;

MySQL: Cascade filtering by date intervals

Can any help me with such type of query.
I have:
posts table
comments table
They are linked through comments.post_id = posts.post_id columns.
I user can filter post by comments for the past:
1 hour
24 hours
2 days, etc.
If user selected to show posts for the past 1 hour, but there no posts this period, we need to go step by step:
Select posts for past 1 hour, if empty - for past 24 hours, if empty - for past 2 days, if empty - since inception (without any conditions).
Could anyone please help me to build such query?
UPD
"Filter posts by comments" means sort by comments count.
So actually goal is request "Show me posts sorted by comments count that have been left for the past XXX hours".
And if is selected "for the past hour" but there are no posts with comments left for the past 1 hour, we need to fetch posts with comments left for the past 24 hours (sorted by comments count) and so on.
Tables structure
Posts:
post_id
title
content
date_added
Comments
comment_id
content
post_id
date_added
So link is posts.post_id = comments.post_id.
I would like to have next result when user view most commented posts for the past hour:
posts.post_id | comments_count | posts.date_added | group
---------------+----------------+------------------+----------------
156 | 8 | 2013-04-02 | hour
154 | 3 | 2013-04-02 | hour
129 | 1 | 2013-03-10 | 24 hours
13 | 14 | 2013-02-18 | 48 hours
138 | 6 | 2013-03-29 | week
137 | 4 | 2013-03-29 | week
161 | 21 | 2013-04-11 | month
6 | 2 | 2013-01-24 | year
103 | 8 | 2013-03-02 | since inception
Results sorted by:
Top of the list is 2 posts that have been commented due the past hour, and ordered by comments count.
Next we place posts that have been commented due the past day.
Next — posts commented due past 2 days
posts commented due past week, and again they should be ordered by comments count
For the past month
For the past year
In the end of this list we need to place articles that have been commented more than year ago, and they also should be ordered by comments count.
Thanks in advance.
Calculate the most recent comment for each group. Then use this to choose which group you want. You can do this calculation with a subquery:
select p.* c.*
from posts p join
comments c
on p.post_id = posts.post_id join
(select post_id, max(postdate) as postdate
from comments
group by post_id
) cmax
on cmax.post_id = p.post_id
where (case when timestampdiff(minute, now(), cmax.timestamp) <= 60
then timestampdiff(minute, now(), c.timestamp) <= 60
when timestampdiff(minute, now(), cmax.timestamp) <= 60*24
then timestampdiff(minute, now(), c.timestamp) <= 60*24
. . .
)
The syntax for the time comparison depends on whether the values are stored as timestamps or datetimes.
If you want the top 5 posts in the last hour, assuming your date_added fields are timestamps, you can use:
SELECT post_id,
count(comment_id) as comments_count,
posts.date_added, 'hour' as grouptime
FROM posts
INNER JOIN comments
ON posts.post_id = comments.post_id
WHERE TIMESTAMPDIFF(HOUR, comments.date_added, NOW()) = 0
GROUP BY posts.post_id
ORDER BY count(comment_id) DESC
LIMIT 5
If you want all of them, just remove LIMIT. For the last 24 hours:
SELECT post_id,
count(comment_id) as comments_count,
posts.date_added, '24 hours' as grouptime
FROM posts
INNER JOIN comments
ON posts.post_id = comments.post_id
WHERE TIMESTAMPDIFF(HOUR, comments.date_added, NOW()) < 24
GROUP BY posts.post_id
ORDER BY count(comment_id) DESC
LIMIT 5
and so on for different time periods.
If you want to get all of them in one go, use UNION between these queries.

MySQL query help with grouping and adding

I have a table called user_logins which tracks user logins into the system. It has three columns, login_id, user_id, and login_time
login_id(INT) | user_id(INT) | login_time(TIMESTAMP)
------------------------------------------------------
1 | 4 | 2010-8-14 08:54:36
1 | 9 | 2010-8-16 08:56:36
1 | 9 | 2010-8-16 08:59:19
1 | 3 | 2010-8-16 09:00:24
1 | 1 | 2010-8-16 09:01:24
I am looking to write a query that will determine the number of unique logins for each day if that day has a login and only for the past 30 days from the current date. So for the output should look like this
logins(INT) | login_date(DATE)
---------------------------
1 | 2010-8-14
3 | 2010-8-16
in the result table 2010-8-16 only has 3 because the user_id 9 logged in twice that day and him logging into the system only counts as 1 login for that day. I am only looking for unique logins for a particular day. Remember I only want the past 30 days so its like a snapshot of the last month of user logins for a system.
I have attempted to create the query with little success what I have so far is this,
SELECT
DATE(login_time) as login_date,
COUNT(login_time) as logins
FROM
user_logins
WHERE
login_time > (SELECT DATE(SUBDATE(NOW())-1)) FROM DUAL)
AND
login_time < LAST_DAY(NOW())
GROUP BY FLOOR(login_time/86400)
I know this is wrong and this returns all logins only starting from the beginning of the current month and doesn't group them correctly. Some direction on how to do this would be greatly appreciated. Thank you
You need to use COUNT(DISTINCT ...):
SELECT
DATE(login_time) AS login_date,
COUNT(DISTINCT login_id) AS logins
FROM user_logins
WHERE login_time > NOW() - interval 30 day
GROUP BY DATE(login_time)
I was a little unsure what you wanted for your WHERE clause because your question seems to contradict itself. You may need to modify the WHERE clause depending on what you want.
As Mark suggests you can use COUNT(DISTINCT...
Alternatively:
SELECT login_day, COUNT(*)
FROM (
SELECT DATE_FORMAT(login_time, '%D %M %Y') AS login_day,
user_id
FROM user_logins
WHERE login_time>DATE_SUB(NOW(), INTERVAL 1 MONTH)
GROUP BY DATE_FORMAT(login_time, '%D %M %Y'),
user_id
)
GROUP BY login_day