I have have this query but cannot make it work properly when I specify a distinct count. I know the syntax must be off somewhere but I am at a loss where.
The group by query that accurately counts by hour is:
SELECT HOUR(dateAdded) AS Hour,
COUNT(dateAdded) AS `user_count`
FROM Track
WHERE dateAdded BETWEEN '2014-04-01' AND '2014-05-02'
OR dateAdded IS NULL
GROUP BY HOUR(dateAdded)
ORDER BY Hour
The new statement with the distinct count adjustments is as follows:
SELECT HOUR(dateAdded) AS Hour,
COUNT(DISTINCT remoteAddr, xForwardedFor) AS `user_count`
FROM Track
WHERE dateAdded BETWEEN '2014-05-01' AND '2014-05-02'
OR dateAdded IS NULL
AND accessMask = '1iczo'
GROUP BY HOUR(dateAdded)
ORDER BY Hour
I know this might be abstract without reference to actual data, I can update the question if you need it for reference.
UPDATE
The answer that was posted put me in the right direction in terms of thinking about the solution but I don't believe it was returning an accurate result. I came up with this solution instead and in case it is useful for anyone else, posted it. This can probably be done much better but its what I was able to come up with and gives accurate results.
SELECT HOUR( dateAdded ) AS HOUR , COUNT( DISTINCT remoteAddr, xForwardedFor ) AS cnt
FROM Track
WHERE accessMask = '1iczo'
AND destination = 'lp_include.php'
AND dateAdded
BETWEEN '2014-05-01'
AND '2014-05-02'
GROUP BY HOUR
ORDER BY HOUR
I think you should do that with a subquery
Don't think you can't do a count(distinct ...) on two columns.
SELECT hour, count(*) as user_count
from
(SELECT HOUR(dateAdded) AS Hour,
remoteAddr,
xForwardedFor
FROM Track
WHERE dateAdded BETWEEN '2014-05-01' AND '2014-05-02'
OR dateAdded IS NULL
AND accessMask = '1iczo'
GROUP BY HOUR(dateAdded), remoteAddr, xForwardedFor) s
group by hour
order by hour
Related
I have question about a MySQL query that is logging error's since updating the MySQL-5.7.
The error is the "only_full_group_by" which is will spoken off on stackoverflow.
In many answers it's stated not to disable this option but improve your sql query.
The query that I'm using is returning the minimum and maximum values of a counter per hour.
SELECT MAX( counter ) AS max,
MIN( counter ) AS min,
DATE_FORMAT(date_time, '%H:%i') AS dt
FROM table1
WHERE date_time >= NOW() - INTERVAL 1 DAY
GROUP BY YEAR(date_time), MONTH(date_time), DAY(date_time), HOUR(date_time)
as I understand from the error message I'm missing one of the items from the SELECT cause in the GROUP BY cause. But however I restort/remove/add items I'm not getting the result I got before the upgrade to MySQL-5.7.
I tried to subquery the main query to improve the SQL query. But somehow I can't recreate the results.
What is it I'm missing?
MySQL isn't able to determine the functional dependence ... between the expressions in the GROUP BY clause, and the expressions in the SELECT list.
The non-aggregate expression in the SELECT list (DATE_FORMAT(date_time, '%H:%i') includes a minutes component. The GROUP BY clause is going to collapse the rows into groups by just hour. So the value of the minutes is indeterminate... we know it's going to come from some row in the group, but there's no guarantee which one.
(The question reference to ONLY_FULL_GROUP_BY seems to indicate that we've got some understanding of indeterminate values...)
The easiest (fewest) changes fix would be to wrap that expression in a MIN or MAX function.
SELECT MAX(t.counter) AS `max`
, MIN(t.counter) AS `min`
, MIN(DATE_FORMAT(t.date_time,'%H:%i')) AS `dt`
FROM table1 t
WHERE t.date_time >= NOW() - INTERVAL 1 DAY
GROUP
BY YEAR(t.date_time)
, MONTH(t.date_time)
, DAY(t.date_time)
, HOUR(t.date_time)
ORDER
BY YEAR(t.date_time)
, MONTH(t.date_time)
, DAY(t.date_time)
, HOUR(t.date_time)
If we want rows returned in a particular order, we should include an ORDER BY clause, and not rely on MySQL-specific extension or behavior of GROUP BY (which may disappear in future releases.)
It's a bit odd to be doing a GROUP BY year, month, day and not including those values in the SELECT list. (It's not invalid to do that, just kind of strange. The conditions in the WHERE clause are guaranteeing that we don't have more than 24 hours span for date_time.
My preference would to do the GROUP BY on the same expression as the non-aggregate in the SELECT list. If I ever needed more than 24 hours, I'd include the date component:
SELECT MAX(t.counter) AS `max`
, MIN(t.counter) AS `min`
, DATE_FORMAT(t.date_time,'%Y-%m-%d %H:00') + INTERVAL 0 DAY AS `dt`
FROM table1 t
WHERE t.date_time >= NOW() - INTERVAL 1 DAY
GROUP
BY DATE_FORMAT(t.date_time,'%Y-%m-%d %H:00') + INTERVAL 0 DAY
ORDER
BY DATE_FORMAT(t.date_time,'%Y-%m-%d %H:00') + INTERVAL 0 DAY
--or--
if we always know it's just one day's worth of date_time, and we only want to return the hour, then we can group by just the hour. The same expression as in the SELECT list.
SELECT MAX(t.counter) AS `max`
, MIN(t.counter) AS `min`
, DATE_FORMAT(t.date_time,'%H:00') AS `dt`
FROM table1 t
WHERE t.date_time >= NOW() - INTERVAL 1 DAY
GROUP
BY DATE_FORMAT(t.date_time,'%H:00')
, DATE_FORMAT(t.date_time,'%Y-%m-%d %H')
ORDER
BY DATE_FORMAT(t.date_time,'%Y-%m-%d %H')
SELECT MAX( counter ) AS max,
MIN( counter ) AS min,
YEAR(date_time) AS g_year,
MONTH(date_time)AS g_month,
DAY(date_time) AS g_day,
HOUR(date_time) AS g_hour
FROM table1
WHERE date_time >= NOW() - INTERVAL 1 DAY
GROUP BY g_year, g_month, g_day, g_hour
Or you can get rid of redundant data if you always do it for 1 day:
SELECT MAX( counter ) AS max,
MIN( counter ) AS min,
DAY(date_time) AS g_day,
HOUR(date_time) AS g_hour
FROM table1
WHERE date_time >= NOW() - INTERVAL 1 DAY
GROUP BY g_day, g_hour
SO i have a task and i need to group my results by Date and by Provider_name but currently my code is listing out multiple dates and Providers. (need to have one provider per day (25 days in all) so my table shows how many messages the provider got that day and how much did they earn)
This needs to be my result. Result table
But this is what i'm currently getting
This is my code currently
SELECT date_format( time, '%Y-%m-%d' ) AS Date, provider_name, COUNT( message_id ) AS Messages_count, SUM( price ) AS Total_price
FROM mobile_log_messages_sms
INNER JOIN service_instances ON service_instances.service_instance_id = mobile_log_messages_sms.service_instance_id
INNER JOIN mobile_providers ON mobile_providers.network_code = mobile_log_messages_sms.network_code
WHERE time
BETWEEN '2017-02-26 00:00:00'
AND time
AND '2017-03-22 00:00:00'
AND price IS NOT NULL
AND price <> ''
AND service IS NOT NULL
AND service <> ''
AND enabled IS NOT NULL
AND enabled >=1
GROUP BY provider_name, time
ORDER BY time DESC
Can you tell me where i've messed up, i really can't figure out the answer.
Try like this:
....
GROUP BY provider_name, date_format( time, '%Y-%m-%d' )
ORDER BY time DESC
You are grouping time which will group the result by time including hour, minute and second so on ... that is why you getting different count from same day. Try grouping by day instead.
time column is datetime. So its grouped by date and time both rather than just date.
Change GROUP BY statement to
GROUP BY provider_name, date_format( time, '%Y-%m-%d' )
I need to select first value for every hour from my db. But I don't know how to reverse order on GROUP BY statement.
How can i rewrite my query (now it selects last value in hour)?
SELECT HOUR(`time`) as hour, mytable.*
FROM mytable
WHERE DATE(`time`) ="2015-09-12" GROUP BY HOUR(`time`) ORDER BY `time` ASC;
This query gave me expected result:
SELECT HOUR(`time`) as hour, sortedTable.* FROM
(SELECT electrolysis.* FROM electrolysis
WHERE DATE(`time`)='2015-09-12' ORDER BY `time`) as sortedTable
GROUP BY HOUR(`time`);
You can just select the MIN HOUR in sub query , try using the query:
SELECT * from mytable WHERE `time` IN (
SELECT MIN(HOUR(`time`)) as `hour`
FROM mytable
WHERE DATE(`time`) ="2015-09-12"
GROUP BY HOUR(`time`) ) ORDER BY `time` ASC;
You can do something like this:-
SELECT sub0.min_time,
mytable.*
FROM mytable
INNER JOIN
(
SELECT MIN(`time`) AS min_time
FROM mytable
GROUP BY HOUR(`time`)
) sub0
ON mytable.`time` = sub0.min_time
WHERE DATE(`time`) ="2015-09-12"
ORDER BY `time` ASC
This is using a sub query to get the smallest time in each hour. This is then joined back against your main table on this min time to get the record that has this time.
Note that there is a potential problem here if there are multiple records that share the same time as the smallest one for an hour. There are ways around this, but that will depend on your data (eg, if you have a unique id field which is always ascending with time then you could select the min id for each hour and join based on that)
You can use below query, which is more optimized just make sure that time field should be indexed.
SELECT HOUR(m.time), m.*
FROM mytable AS m
JOIN
(
SELECT MIN(`time`) AS tm
FROM mytable
WHERE `time` >= '2015-09-12 00:00:00' AND `time` <= '2015-09-12 23:59:59'
GROUP BY HOUR(`time`)
) AS a ON m.time=a.tm
GROUP BY HOUR(m.time)
ORDER BY m.time;
I am at a loss of how to accomplish this but have seen online ISNULL() and COALESCE() used to return a zero if the query is null. I am unsure though how to use it properly though I am intuitively thinking i need to have in a subquery then have ISNULL or COALESCE around that subquery?
The query goes:
SELECT HOUR( dateAdded ) AS HOUR , COUNT( DISTINCT remoteAddr, xForwardedFor) AS cnt
FROM Track
WHERE accessMask = '1iczo'
AND destination = 'lp_include.php'
AND dateAdded
BETWEEN '2014-05-01'
AND '2014-05-02'
GROUP BY HOUR
ORDER BY HOUR
Some help in the right direction would be greatly appreciated!
UPDATE
I used what #Barmar had suggested but it wasn't returning accurate results. I used what he provided and also another topic with a similar situation, Group by should return 0 when grouping by hours. How to do this? . I actually didn't find this topic till after posting this one, :( unfortunately. Here is the final code that appears to return accurate results, distinct across two columns with empty data being returned as 0.
SELECT a.hour, COALESCE(cnt, 0) AS cnt
FROM (SELECT 0 AS hour
UNION ALL
SELECT 1
UNION ALL
SELECT 2 .....
UNION ALL
SELECT 23) a
LEFT JOIN
(SELECT COUNT(DISTINCT remoteAddr, xForwardedFor) AS cnt, HOUR(dateAdded) AS hour
FROM Track
WHERE accessMask = '1iczo'
AND destination = 'lp_include.php'
AND dateAdded
BETWEEN '2014-05-01 00:00:00' AND '2014-05-01 23:59:59') AS totals
ON a.hour = totals.hour
Fiddle for better reference: http://sqlfiddle.com/#!2/9ab660/7
Thanks again to #Barmar, he really put me in the right direction to get to the solution!
You have to join with a table that contains all the hours. This must be a LEFT JOIN so that the results will include hours that have no matches in Track table.
SELECT allHours.hour, IFNULL(cnt, 0) AS cnt
FROM (SELECT 0 AS hour
UNION
SELECT 1
UNION
SELECT 2
UNION
SELECT 3
...
UNION
SELECT 23) AS allHours
LEFT JOIN
(SELECT HOUR(dateAdded) AS hour, COUNT(DISTINCT remoteAddr, xForwardedFor) AS cnt
FROM Track
WHERE accessMask = '1iczo'
AND destination = 'lp_include.php'
AND dateAdded
BETWEEN '2014-05-01' AND '2014-05-02') AS totals
ON allHours.hour = totals.hour
If you assume that you have some data for every hour, you can move the conditional part into the select:
SELECT HOUR(dateAdded) AS HOUR ,
COUNT(DISTINCT CASE WHEN accessMask = '1iczo' AND destination = 'lp_include.php'
THEN CONCAT(remoteAddr, ',', xForwardedFor)
END) AS cnt
FROM Track
WHERE dateAdded BETWEEN '2014-05-01' AND '2014-05-02'
GROUP BY HOUR
ORDER BY HOUR;
Lets say I have a table of messages that users have sent, each with a timestamp.
I want to make a query that will tell me (historically) the most number of messages a user ever sent in an hour.
So in other words, in any given 1 hour period, what was the most number of messages sent.
Any ideas?
Assuming timestamp to be a DATETIME - otherwise, use FROM_UNIXTIME to convert to a DATETIME...
For a [rolling] count within the last hour:
SELECT COUNT(*) AS cnt
FROM MESSAGES m
WHERE m.timestamp BETWEEN DATE_SUB(NOW(), INTERVAL 1 HOUR)
AND NOW()
GROUP BY m.user
ORDER BY cnt DESC
LIMIT 1
If you want a specific hour, specify the hour:
SELECT COUNT(*) AS cnt
FROM MESSAGES m
WHERE m.timestamp BETWEEN '2011-06-06 14:00:00'
AND '2011-06-06 15:00:00'
GROUP BY m.user
ORDER BY cnt DESC
LIMIT 1
Need more details on table structure etc. but something like:
select date(timestmp), hour(timestmp) , count(*)
from yourtable group by date(timestmp) , hour(timestmp)
order by count(*) DESC
limit 100;
would give you hte desired result.
Something like this should work:
SELECT MAX(PerHr) FROM
(SELECT COUNT(*) AS PerHr FROM messages WHERE msg_uid=?
GROUP BY msg_time/3600) t
I suspect this would be horribly slow, but for an arbitrary historical max hour, something like this might work (downvote me if I'm way off, I'm not a MySQL person):
SELECT base.user, base.time, COUNT(later.time)
FROM messages base
INNER JOIN messages later ON later.time BETWEEN base.time AND DATE_ADD(base.time, INTERVAL 1 HOUR) AND base.user = later.user
WHERE base.user = --{This query will only work for one user}
GROUP BY base.user, base.time
ORDER BY COUNT(later.time) DESC
LIMIT 1