Help me with next SQL:
SELECT
date_format(from_unixtime(`ticket_logs`.`created`),'%Y-%m-%d') AS `datac`,
`ticket_logs`.`ticket_id` AS `ticket_id`,
ticket_logs.value_old,
ticket_logs.value_new,
max(`ticket_logs`.`action`) AS `ultima_act`
FROM
`ticket_logs`
WHERE
(
(`ticket_logs`.`action` = 6)
OR (`ticket_logs`.`action` = 16)
)
GROUP BY
date_format(
from_unixtime(`ticket_logs`.`created`),
'%Y-%m-%d'
),
`ticket_logs`.`ticket_id`
ORDER BY
`datac` DESC,
`ticket_logs`.`ticket_id` DESC
The problem is that "value_old" and "value_new", always take the first value per date and not the value corresponding with the max value of "action"
I don't see how this is a problem. That is how SQL works -- the order by takes place after the group by. In addition, MySQL is just confusing you, because you are using an extension to group by that you don't fully understand -- having extra columns in the select that are not in the group by. (See this.)
Fortunately, MySQL supports a hack to get what you want, without writing a much more complicated SQL statement. The expressions you want are:
substring_index(group_concat(ticket_logs.value_old order by `ticket_logs`.`action` desc), ',', 1)
substring_index(group_concat(ticket_logs.value_new order by `ticket_logs`.`action` desc), ',', 1)
Found another approach. I used the "created" column to obtain a max and joined:
SELECT
date_format(
from_unixtime(`ticket_logs`.`created`),
'%Y-%m-%d'
) AS `datax`,
ticket_logs.ticket_id,
ticket_logs.action,
ticket_logs.value_old,
ticket_logs.value_new
FROM
ticket_logs
INNER JOIN (
SELECT
date_format(
from_unixtime(`ticket_logs`.`created`),
'%Y-%m-%d'
) AS `datac`,
max(ticket_logs.created) AS maxts,
ticket_id
FROM
ticket_logs
WHERE
ticket_logs.action = 6
OR ticket_logs.action = 16
GROUP BY
date_format(
from_unixtime(`ticket_logs`.`created`),
'%Y-%m-%d'
),
ticket_id
) maxtbl ON ticket_logs.ticket_id = maxtbl.ticket_id
AND ticket_logs.created = maxtbl.maxts
ORDER BY
datax DESC,
ticket_id DESC
Related
Does anyone know what's wrong with this query?
This works perfectly on its own:
SELECT * FROM
(SELECT * FROM data WHERE site = '".$id."'
AND disabled = '0'
AND carvotes NOT LIKE '0'
AND (time > ( now( ) - INTERVAL 14 DAY ))
GROUP BY car ORDER BY carvotes DESC LIMIT 0 , 10)
X order by time DESC
So does this:
SELECT * FROM data WHERE site = '".$id."' AND disabled = '0' GROUP BY car DESC ORDER BY time desc LIMIT 0 , 30
But combining them like this:
SELECT * FROM data WHERE site = '".$id."' AND disabled = '0' AND car NOT IN (SELECT * FROM
(SELECT * FROM data WHERE site = '".$id."'
AND disabled = '0'
AND carvotes NOT LIKE '0'
AND (time > ( now( ) - INTERVAL 14 DAY ))
GROUP BY car ORDER BY carvotes DESC LIMIT 0 , 10)
X order by time DESC) GROUP BY car DESC ORDER BY time desc LIMIT 0 , 30
Gives errors. Any ideas?
Please try the following...
$result = mysqli_query( $con,
"SELECT *
FROM data
WHERE site = '" . $id .
"' AND disabled = '0'
AND car NOT IN ( SELECT car
FROM ( SELECT car,
carvotes
FROM data
WHERE site = '" . $id .
"' AND disabled = '0'
AND carvotes NOT LIKE '0'
AND ( time > ( NOW( ) - INTERVAL 14 DAY ) )
GROUP BY car
ORDER BY carvotes DESC
LIMIT 10 ) X
)
GROUP BY car
ORDER BY time DESC
LIMIT 30" );
The main cause of your problem is that with car NOT IN ( SELECT * FROM ( SELECT *... you are trying to compare each record's value of car with each row returned by your subquery. IN requires you to have the same number of fields on both sides of the comparison. By using SELECT * at both levels of the subquery you were ensuring that the right side of the comparison had however many fields are in data versus your single field on the left, which confused MySQL.
Since you are aiming to compare to a single field, namely car, our subquery has to select just the car field from its dataset. Since the sort order of the subquery's results has no effect upon the IN comparison, and since our innermost query will be returning just car, I have removed the outer level of the subquery.
Beyond changing the first part of the subquery to SELECT car, the only other change that I have made to the subquery is to change LIMIT 0, 10 to LIMIT 10. The former means limit to the the 10 records that are offset by 0 from the first record. This is useful if you want records 6 to 15, but redundant for 1 to 10 as LIMIT 10 has the same affect and is slightly simpler. Ditto for LIMIT 0, 30 at the end of your overall statement.
As for the main body of the statement, I have not made any attempt to specify what fields (or aggregate functions of those fields) should be returned since you have made no statement indicating what your requirements / preferences are. If you are satisfied that GROUP BY has left you with a still valid set of values, then all the good, but if not then I recommend that you rewrite your Question to be specific about that detail.
By default, MySQL sorts the data subjected to a GROUP BY into ascending order, but if an ORDER BY clause is also present then it overrides the GROUP BY's sort pattern. As such, there is no benefit to specifying DESC after either of your GROUP BY car clauses, so I have removed it where it occurs.
Interesting Sidenote : You can override a GROUP BY's sort by specifying ORDER BY NULL.
If you have any questions or comments, then please feel free to post a Comment accordingly.
Further Reading
https://dev.mysql.com/doc/refman/5.7/en/order-by-optimization.html - on optimising your ORDER BY sorting
https://dev.mysql.com/doc/refman/5.7/en/select.html - on the SELECT statement's syntax - specifically the parts to do with LIMIT.
https://www.w3schools.com/php/php_mysql_select_limit.asp - a simpler explanation of LIMIT
This is your query:
SELECT *
FROM data
WHERE site = '".$id."' AND disabled = '0' AND
car NOT IN (SELECT *
FROM (SELECT *
FROM data
WHERE site = '".$id."' AND
disabled = '0' AND
carvotes NOT LIKE '0' AND
(time > ( now( ) - INTERVAL 14 DAY ))
GROUP BY car
ORDER BY carvotes DESC
LIMIT 0 , 10
) x
ORDER BY time DESC
)
GROUP BY car DESC
ORDER BY time desc
LIMIT 0 , 30 ;
Several comments:
Do not wrap integer constants in single quotes. This can mislead people. This can mislead optimizers.
Do not use string functions on integers (such as like). Same reason.
NOT IN with subqueries is dangerous. The construct does not handle NULL values the way you expect. Use NOT EXISTS or LEFT JOIN instead.
When using subqueries, ORDER BY is almost never appropriate.
Never use SELECT * with GROUP BY. It is just wrong. Happily, MySQL 5.7 has changed its defaults to reject this anti-pattern
So, a better way to write this query is something like this:
SELECT d.car, MAX(time) as time
FROM data d LEFT JOIN
(SELECT d2.*
FROM data d2
WHERE d2.site = '".$id."' AND
d2.disabled = 0 AND
d2.carvotes NOT LIKE 0 AND
(d2.time > ( now( ) - INTERVAL 14 DAY ))
GROUP BY d2.car
ORDER BY carvotes DESC
LIMIT 0 , 10
) car10
ON d.car = car10.car
WHERE d.site = '".$id."' AND d.disabled = 0' AND
car10.car IS NOT NULL
GROUP BY car DESC
ORDER BY MAX(time) desc
LIMIT 0 , 30 ;
Alternatively, use SELECT * and remove the GROUP BY in the outer query.
I have a single table with rows like this: (Date, Score, Name)
The Date field has two possible dates, and it's possible that a Name value will appear under only one date (if that name was recently added or removed).
I'm looking to get a table with rows like this: (Delta, Name), where delta is the score change for each name between the earlier and later dates. In addition, only a negative change interests me, so if Delta>=0, it shouldn't appear in the output table at all.
My main challenge for me is calculating the Delta field.
As stated in the title, it should be an SQL query.
Thanks in advance for any help!
I assumed that each name can have it's own start/end dates. It can be simplified significantly if there are only two possible dates for the entire table.
I tried this out in SQL Fiddle here
SELECT (score_end - score_start) delta, name_start
FROM
( SELECT date date_start, score score_start, name name_start
FROM t t
WHERE NOT EXISTS
( SELECT 1
FROM t x
WHERE x.date < t.date
AND x.name = t.name
)
) AS start_date_t
JOIN
( SELECT date date_end, score score_end, name name_end
FROM t t
WHERE NOT EXISTS
( SELECT 1
FROM t x
WHERE x.date > t.date
AND x.name = t.name
)
) end_date_t ON start_date_t.name_start = end_date_t.name_end
WHERE score_end-score_start < 0
lets say you have a table with date_value, sum_value
Then it should be something like that:
select t.date_value,sum_value,
sum_value - COALESCE((
select top 1 sum_value
from tmp_num
where date_value > t.date_value
order by date_value
),0) as sum_change
from tmp_num as t
order by t.date_value
The following uses a "trick" in MySQL that I don't really like using, because it turns the score into a string and then back into a number. But, it is an easy way to get what you want:
select t.name, (lastscore - firstscore) as diff
from (select t.name,
substring_index(group_concat(score order by date asc), ',', 1) as firstscore,
substring_index(group_concat(score order by date desc), ',', 1) as lastscore
from table t
group by t.name
) t
where lastscore - firstscore < 0;
If MySQL supported window functions, such tricks wouldn't be necessary.
Ok, so I have the following query:
SELECT MIN(`date`), `player_name`
FROM `player_playtime`
GROUP BY `player_name`
I then need to use this result inside the following query:
SELECT DATE(`date`) , COUNT(DISTINCT `player_name`)
FROM `player_playtime /*Use previous query result here*/`
GROUP BY DATE( `date`) DESC LIMIT 60
How would I go about doing this?
You just need to write the first query as a subquery (derived table), inside parentheses, pick an alias for it (t below) and alias the columns as well.
The DISTINCT can also be safely removed as the internal GROUP BY makes it redundant:
SELECT DATE(`date`) AS `date` , COUNT(`player_name`) AS `player_count`
FROM (
SELECT MIN(`date`) AS `date`, `player_name`
FROM `player_playtime`
GROUP BY `player_name`
) AS t
GROUP BY DATE( `date`) DESC LIMIT 60 ;
Since the COUNT is now obvious that is only counting rows of the derived table, you can replace it with COUNT(*) and further simplify the query:
SELECT t.date , COUNT(*) AS player_count
FROM (
SELECT DATE(MIN(`date`)) AS date
FROM player_playtime
GROUP BY player_name
) AS t
GROUP BY t.date DESC LIMIT 60 ;
Folks
when i m running the below query , i m getting the error for invalid use of group by function
SELECT `Margin`.`destination`,
ROUND(sum(duration),2) as total_duration,
sum(calls) as total_calls
FROM `ilax`.`margins` AS `Margin`
WHERE `date1` = '2013-08-30' and `destination` like "af%"
AND ROUND(sum(duration),2) like "3%"
group by `destination`
ORDER BY duration Asc LIMIT 0, 20;
let me know the work around
The WHERE clause is evaluated before grouping takes place, so SUM() cannot be used therein; use the HAVING clause instead, which is evaluated after grouping:
SELECT destination,
ROUND(SUM(duration), 2) AS total_duration,
SUM(calls) AS total_calls
FROM ilax.margins
WHERE date1 = '2013-08-30'
AND destination LIKE 'af%'
GROUP BY destination
HAVING total_duration LIKE '3%'
ORDER BY total_duration ASC
LIMIT 0, 20
Note also that one really ought to use numeric comparison operations for numeric values, rather than string pattern matching. For example:
HAVING total_duration >= 3000 AND total_duration < 4000
can any one help me to convert the following query into mssql which is working on postgresql now
query is to take the updated datetime of the report in the asc order of the date
select
count(*) as count,
TO_CHAR(RH.updated_datetime,'dd-mm-YYYY') as date,
SUM(
extract (
epoch from (
RH.updated_datetime - PRI.procedure_performed_datetime
)
)
)/count(*) as average_reporting_tat
from
report R,
report_history RH,
study S,
procedure_runtime_information PRI,
priorities PP,
patient P,
procedure PR
where
RH.report_fk=R.pk and RH.pk IN (
select pk from (
select * from report_history where report_fk=r.pk order by revision desc limit 1
) as result
where old_status_fk IN (21, 27)
) AND R.study_fk = S.pk
AND S.procedure_runtime_fk = PRI.pk
AND PRI.procedure_fk = PR.pk
AND S.priority_fk = PP.pk
AND PRI.patient_fk = P.pk
AND RH.updated_datetime >= '2013-05-01'
AND RH.updated_datetime <= '2013-05-12'
group by date
If I read your query properly, your problem is that you need to list everything in the group by clause that is in your column list which is not part of an aggregate. So your group by needs to be:
GROUP BY RH.updated_datetime
If this doesn't fix it, please post the error message you are getting.