I have the following 2 queries.
Query 1 :
select distinct(thread_id) from records where client_name='MyClient'
Query 2 :
select max(thread_no) from records
where thread_id='loop_result_from_above_query' AND action='Reviewed'
Is it possible to combine them into a single query ?
The second query is run on every result of the first query.
Thank you.
See attached image of a small snippet of mysql records.
I need a single mysql query to output only records which have action="MyAction" as the latest records for a given set of thread_ids. In the sample data set : record with Sr: 7201
I hope this helps in helping me :)
SELECT client_name, thread_id, MAX(thread_no) max_thread
FROM records
WHERE action='Reviewed' AND client_name='MyClient'
GROUP BY client_name, thread_id
UPDATE 1
SELECT a.*
FROM records a
INNER JOIN
(
SELECT thread_id, max(sr) max_sr
FROM records
GROUP BY thread_id
) b ON a.thread_id = b.thread_id AND
a.sr = b.max_sr
WHERE a.action = 'MyAction'
You can use SELF JOIN, but it is not advisable and will impact your query performance. Please check below query for your reference
SELECT DISTINCT r1.thread_id, MAX(r2.thread_no) from records r1 LEFT JOIN records r2 ON r2.thread_id=r1.thread_id WHERE r1.client_name='MyClient' AND r2.action='Reviewed'
SELECT a.maxthreadid,
b.maxthreadno
FROM (SELECT DISTINCT( thread_id ) AS MaxThreadId
FROM records
WHERE client_name = 'MyClient') a
CROSS JOIN (SELECT Max(thread_no) AS MaxThreadNo
FROM records
WHERE thread_id = 'loop_result_from_above_query'
AND action = 'Reviewed') b
Try this.
SELECT *
FROM (SELECT Row_number()
OVER (
partition BY thread_id
ORDER BY thread_no) no,
Max(thread_no)
OVER(
partition BY thread_id ) Maxthread_no,
thread_id,
action,
client_name
FROM records
Where client_name = 'MyClient') AS T1
WHERE no = 1
AND action = 'Reviewed'
Related
This has to be a no brainer, but I am stumped. I'm used to using aggregate 'FIRST' in MsAccess, but MySql has no such thing.
Here is a simple table. I want to return the most recent record based on the date,
for each unique 'group ID'. I need the three records in yellow.
I was asked to add my full query. I tried one of the suggestions using the JOIN feature replacing 't' with the temp table name, but it failed to work. "Can't reopen table 't'"
The code is below. I know it's ugly, but it does return the correct data set.
I cleaned up the code a bit and added the JOIN code. Error: "Can't reopen table 't'"
enter code here
DROP TABLE IF EXISTS `tmpMaxLookupResults`;
create temporary table tmpMaxLookupResults
as
SELECT
REPORTS.dtmReportCompleted,
RESULTS.lngMainReport_ID, RESULTS.lngLocationGroupSub_ID
FROM
(tbl_010_040_ProcedureVsTest_Sub as ProcVsSub
INNER JOIN tbl_010_050_CheckLog_RESULTS as RESULTS
ON (ProcVsSub.lngLocationGroupSub_ID = RESULTS.lngLocationGroupSub_ID)
AND (ProcVsSub.lngProcedure_ID = RESULTS.lngProcedure_ID)
AND (ProcVsSub.lngItemizedTestList_ID = RESULTS.lngItemizedTestList_ID)
AND (ProcVsSub.strPasscodeAdmin = RESULTS.strPasscodeAdmin)
AND (ProcVsSub.strCFICode = RESULTS.strCFICode))
INNER JOIN
tbl_000_010_MAIN_REPORT_INFO as REPORTS ON (RESULTS.lngPCC_ID =
REPORTS.lngPCC_ID)
AND (RESULTS.lngProcedure_ID = REPORTS.lngProcedure_ID)
AND (RESULTS.lngMainReport_ID = REPORTS.idMainReport_ID)
AND (RESULTS.strPasscodeAdmin = REPORTS.strPasscodeAdmin)
AND (RESULTS.strCFICode = REPORTS.strCFICode)
WHERE
(((RESULTS.lngProcedure_ID) = 143)
AND ((RESULTS.dtmExpireDate) IS NOT NULL)
AND ((RESULTS.strCFICode) = 'ems'))
GROUP BY RESULTS.lngMainReport_ID, RESULTS.lngLocationGroupSub_ID
ORDER BY (REPORTS.dtmReportCompleted) DESC;
SELECT t.*
FROM tmpMaxLookupResults AS t
JOIN (
SELECT lngLocationGroupSub_ID,
MAX(dtmReportCompleted) AS max_date_completed
FROM tmpMaxLookupResults
GROUP BY lngLocationGroupSub_ID ) AS dt
ON dt.lngLocationGroupSub_ID = t.lngLocationGroupSub_ID AND
dt.max_date_completed = t.dtmReportCompleted
enter code here
Try this
SELECT
tn.*
FROM
tableName tn
RIGHT OUTER JOIN
(
SELECT
groupId, MAX(date_completed) as max_date_completed
FROM
tableName
GROUP BY
groupId
) AS gt
ON
(gt.max_date_completed = nt.date_completed AND gt.groupId = nt.groupId)
You can use the following SQL.
select * from table1 order by date_completed desc Limit 1;
Use Order By
SELECT *
FROM table_name
ORDER BY your_date_column_name
DESC
LIMIT 1
In a Derived Table, get the maximum date_completed value for every group_id.
Join this result-set back to the main table, in order to get the complete row corresponding to maximum date_completed value for every group_id
Try the following query:
SELECT t.*
FROM your_table_name AS t
JOIN (
SELECT group_id,
MAX(date_completed) AS max_date_completed
FROM your_table_name
GROUP BY group_id
) AS dt
ON dt.group_id = t.group_id AND
dt.max_date_completed = t.date_completed
I have such a query:
SELECT
*,
(
SELECT COUNT(DISTINCT client_id)
FROM 1097_course_students_tbl
WHERE course_cycl_id=id
AND stts_id <> 8
AND client_id IN(SELECT id FROM 1097_clients_tbl WHERE is_removed=0)
) AS cnt
FROM 1097_course_cycle_tbl
WHERE (course_id IN (SELECT id FROM 1097_courses_tbl WHERE is_removed=2))
ORDER BY start_date DESC
I need to make it more efficient because it takes too long
any suggestions ?
thanks
Try the following
SELECT cc.*,IFNULL(q.cnt,0) cnt
FROM 1097_course_cycle_tbl cс
JOIN 1097_courses_tbl с ON c.id=cc.course_id AND c.is_removed=2
LEFT JOIN
(
SELECT cs.course_cycl_id,COUNT(DISTINCT cs.client_id) cnt
FROM 1097_course_students_tbl cs
JOIN 1097_clients_tbl c ON cs.client_id=c.id AND c.is_removed=0
WHERE cs.stts_id<>8
GROUP BY cs.course_cycl_id
) q
ON q.course_cycl_id=cс.id
ORDER BY cc.start_date DESC
I think id in 1097_courses_tbl and 1097_clients_tbl is primary key.
Therefore I replaced IN into JOIN.
And I converted the subquery from SELECT block wich executed for each rows into the subquery with GROUP BY which using in LEFT JOIN. Here it'll execute only one time and return all the necessary information.
I have two tables in MySql db.
1) networks (NetworkId, NetworkType)
2) users (Id, NetworkId, IpAddress)
Using [NetworkId and IpAddress] defines unique users.
Now, I want to use group by clause on NetworkType and at the same time want to list count of all users as like below:
SELECT (SELECT Count(distinct IpAddress) FROM users
WHERE NetworkId in nr.NetworkId ) as UsersCount
FROM networks as nr
GROUP BY NetworkType;
But due to any reason I always gets zero users.
When I run following queries
SELECT GROUP_CONCATE(nr.NetworkId)
FROM networks as nr
GROUP BY NetworkType;
Then I am getting valid values with ',' separated.
Thanks in advance.
Updated per your new information about what you needed with the group by.
How about an upvote for my efforts at least.
Latest SQLFIDDLE
select
mysub.count,
nr.`networkid`
from
`networks` as nr,
(select
count(`ipaddress`) as count,
`networkid`
from
`users`
where
`networkid`
in (
select
`networkid`
from
`networks`
)
group by
`networkid`) as mysub
where nr.`networkid` = mysub.`networkid`
group by nr.`networkid`
Something like this perhaps:
select n.networktype, count(distinct u.ipaddress)
from networks n
join users u on n.networkid = u.networkid
group by n.networktype
I am trying to retrieve the max(date_entered) for a group of computer_ids.
The first query won't return accurate results. The second query gives me accurate results but essentially hangs unless I filter by a specific computer_id.
I'd rather use this first query
SELECT *, max(reports.date_entered)
FROM reports, hardware_reports
WHERE reports.report_id=hardware_reports.report_id
GROUP BY computer_id;
than this second query
SELECT *
FROM reports a
JOIN hardware_reports
ON a.report_id=hardware_reports.report_id
AND a.date_entered = (
SELECT MAX(date_entered)
FROM reports AS b
WHERE a.computer_id = b.computer_id)
and computer_id = 1648;
I need to either optimize second or get max to work in first.
You can alternative join it on a subquery that gets the latest record for every computer_ID.
SELECT a.*, c.*
FROM reports a
INNER JOIN
(
SELECT computer_ID, MAX(date_entered) date_entered
FROM reports
GROUP BY computer_ID
) b ON a.computer_ID = b.computer_ID
AND a.date_entered = b.date_entered
INNER JOIN hardware_reports c
ON a.report_id = c.report_id
To make it more efficient, provide an index on columns:
ALTER TABLE reports INDEX idx_report_compDate (computer_ID, date_entered)
I have the following query. If I run it I get this error message.
Query-
SELECT account_name,ABC,date FROM entries
LEFT JOIN accounts ON accounts.id = entries.accounts_id
LEFT JOIN voucher ON voucher.id = entries.trans_id
WHERE trans_id IN ( SELECT trans_id, amount AS ABC FROM entries
WHERE accounts_id='$accounts_id' AND side='C')
AND accounts_id!='$accounts_id' AND side='D'
AND voucher.date between '$dateragne1' AND '$dateragne2'
I think the problem is with the value ABC. It is unable to fetch the value from the second query.
Could you please tell me how to fix this query?
Thanks in Advance :)
Try this:
SELECT account_name, _inner.ABC, date
FROM
(
SELECT amount AS ABC FROM entries
WHERE accounts_id='$accounts_id' AND side='C'
) AS _inner, entries
LEFT JOIN accounts ON accounts.id = entries.accounts_id
LEFT JOIN voucher ON voucher.id = entries.trans_id
WHERE trans_id IN
(
SELECT trans_id FROM entries WHERE accounts_id='$accounts_id' AND side='C'
)
AND accounts_id!='$accounts_id' AND side='D'
AND voucher.date between '$dateragne1' AND '$dateragne2'`
Notes:
Using subquery like this doesn't allow you to request a fields from it.
Also, IN statement use data from only only column, not two.