I have an Access table (Logs) like this:
pk
modID
relID
DateTime
TxType
1
1234
22.3
10/1/22 04:00
1
2
1234
23.1
10/10/22 06:00
1
3
1234
23.1
10/11/22 07:00
2
4
1234
23.1
10/12/22 08:00
3
5
4321
22.3
10/2/22 06:00
7
6
4321
23.1
10/10/22 06:00
1
7
4321
23.1
10/11/22 07:30
3
Trying to write a query as part of a function that searches this table:
for all records matching a given modID and relID (e.g. 1234 and 23.1),
picks the most recent one (the MAX of DateTime),
returns the TxType for that record.
However, a bit new to Access and its query structure is vexing me. I landed on this but because I have to include a Total/Aggregate function for TxType I had to either choose Group By (not what I want) or Last (closer, but returns junk results). The SQL for my query is currently:
SELECT Last(Logs.TxType) AS LastOfTxType, Max(Logs.DateTime) AS MaxOfDateTime
FROM Logs
GROUP BY Logs.dmID, Logs.relID
HAVING (((Logs.dmID)=[EnterdmID]) AND ((Logs.relID)=[EnterrelID]));
It returns the TxType field when I pass it the right parameters, but not the correct record - I would like to be rid of the Last() bit but if I remove it Access complains that I don't have it as part of an aggregate function.
Anyone that can point me in the right direction here?
Have you tried
SELECT TOP 1 TxtType
FROM Logs
WHERE (((Logs.dmID)=[EnterdmID]) AND ((Logs.relID)=[EnterrelID]))
ORDER BY DateTime DESC;
That will give you the latest single data row based on your DateTime field and other criteria.
Related
Struggling with ms-access's flavor of SQL queries still, though I've made some progress (thanks to y'all). I have an event log table like this:
Logs Table
logID (auto#)
modID (str)
relID (str)
DateTime (date)
TxType (short)
1
1234
22.3
10/1/22 0800
6
2
1234
22.3
10/1/22 0900
7
3
1234
22.3
10/1/22 1000
13
4
1234
22.3
10/1/22 1100
15
5
4321
22.3
10/1/22 0830
1
6
4321
22.3
10/1/22 0930
13
7
4321
22.3
10/1/22 1030
15
8
4321
22.3
10/1/22 1130
13
9
1234
23.1
11/1/22 0800
1
10
1234
23.1
11/1/22 0900
15
11
1234
23.1
11/1/22 1000
13
12
1234
23.1
11/1/22 1100
15
13
4321
23.1
11/1/22 0830
13
14
4321
23.1
11/1/22 0930
7
15
4321
23.1
11/1/22 1030
13
16
4321
23.1
11/1/22 1130
15
What I need to do is:
filter the table by relID, then
count the number of modID's that have a 15 txType as the last/most recent chronological event in their rows.
So ideally I'd filter e.g. by relID=23.1 and get these results (but not logID # 10 for example) and then count them:
logID (auto#)
modID (str)
relID (str)
DateTime (date)
TxType (short)
12
1234
23.1
11/1/22 1100
15
16
4321
23.1
11/1/22 1130
15
As part of another function I have been able to count any modID's having a single txType successfully using
SELECT COUNT(*)
FROM (
SELECT DISTINCT Logs.modID, Logs.relID
FROM Logs
WHERE ((Logs.relID='23.1') AND ((Logs.TxType=13)))
);
Another stackoverflow user (exception - thanks!) showed me how to get the last event type for a given modID, relID combination using
SELECT TOP 1 TxType
FROM Logs
WHERE (((Logs.modID=[EnterModID])) AND ((Logs.relID=[EnterRelID])))
ORDER BY DateTime DESC;
But I'm having trouble combining these two. I know I can combine COUNT and GROUP BY but Access treats GROUP BY very particularly, and I'm not sure how to use SELECT TOP to get the latest events for each modID rather than just the latest events in the table, period.
This should give you the logID from the row with the latest DateTime for each combination of modIDand your target relID:
PARAMETERS which_relID Text(255);
SELECT DISTINCT
(
SELECT TOP 1 logID
FROM Logs
WHERE modID=l.modID AND relID=l.relID
ORDER BY [DateTime] DESC
) AS latest_modID
FROM Logs AS l
WHERE l.relID=[which_relID]
Use it as a subquery which you INNER JOIN to your Logs table. Note the subquery evaluates rows regardless of TxType. So have the parent query select only rows whose TxType = 15
PARAMETERS which_relID Text(255);
SELECT l2.*
FROM
Logs AS l2
INNER JOIN
(
SELECT DISTINCT
(
SELECT TOP 1 logID
FROM Logs
WHERE modID=l.modID AND relID=l.relID
ORDER BY [DateTime] DESC
) AS latest_modID
FROM Logs AS l
WHERE l.relID=[which_relID]
) AS sub
ON l2.logID=sub.latest_modID
WHERE l2.TxType=15;
Note I moved the PARAMETERS clause into the parent query. But you can eliminate it altogether if you believe it's causing trouble.
DateTime is a reserved word. I enclosed it in square brackets to ensure Access understands we mean the name of an object.
Using your sample data, I get these 2 rows when I supply 23.1 for the query parameter:
logID
modID
relID
DateTime
TxType
12
1234
23.1
11/1/2022 11:00:00 AM
15
16
4321
23.1
11/1/2022 11:30:00 AM
15
I get a single row with 22.3 for the parameter:
logID
modID
relID
DateTime
TxType
4
1234
22.3
10/1/2022 11:00:00 AM
15
seconfHere is an example:
ID Datetime1 datetime2 (Results needed)
1 1/1/2010 7:54 1/2/2010 6:54 23
1 1/1/2010 7:54 1/4/2010 6:54 48
1 1/1/2010 7:54 1/5/2010 6:54 24
2 1/5/2010 11:00 1/8/2010 11:00 72
3 1/30/2010 23:05 2/1/2010 22:05 47
notice ID 1 in the first row it did a normal datediff but in the second and third row I need it to use the startdate of datetime2 and enddate of datetime2 of thee same ID.
turnaround time column is what is the output column I need, I only tried normal datediff but it just calculates the difference between datetime1 and datetime2. my problem is that it can be many IDs with a value of 1, so I need the datediff to dynamically update the startdate if another enddate exist for the same ID.
Im' working in a RDBMS 'Microsoft SQL server'
the code i tried is as followed:
select
*
,datediff(hh,datetime1,datetime2) as 'Turnaround time'
from
my_table
order by datetime1 asc
i hope this clears it out a little bit.
thank you in advance
the answer was Lead and Lag functions URL below:
https://www.databasejournal.com/features/mssql/lead-and-lag-functions-in-sql-server-2012.html
So I have a list with datetimes, mostly there is the same datetimes twice. In the same row of the Dates there is a number which should be summed up and listed in another sheet.
List example (What I Have now):
1 07.09.2015 09:00 118
2 07.09.2015 09:00 31
3 07.09.2015 08:00 148
4 07.09.2015 08:00 56
5 07.09.2015 07:00 128
6 07.09.2015 07:00 49
The List could/should goes like this 24 hours a day 365 times a year, actually its just 3 months at the moment.
And I only want to have one Datetime with one number as sum behind.
It also could be posible that there is the same datetime more than twice
So it should look like this in the desired sheet:
1 07.09.2015 09:00 149
2 07.09.2015 08:00 204
3 07.09.2015 07:00 177
I'm not the best in excel VBA and i only can write a bit of code....
Use a pivot table.
Select all your data. (make sure you have header column and if not add)
select the insert Ribbon and - Insert -> pivot table.
Drag your the date to the rpws and the values as sum the values.
You can refrsh the table each time you add data to the data table by choosing Analyze ribbon -> refresh.
If you want to macro this process , the most simple way for starters is to copy a macro. You can view the code later and improve it.
Please note: this is not for an Access project as such, but a legacy application that uses an Access database for its back end.
Setup
Part of the application is a kind of Gantt chart, fixed to single day columns, where each row represents a single resource. Resources are booked out for a range of days and a booking is for a single resource, so they cannot overlap on a row. The range of dates that is in view is user selectable, open ended, and can be changed by various methods, including horizontal scrolling using mouse or keyboard.
Problem
I've been tasked with adding a row to the top of the chart to indicate overall resource usage for each day. Of course that's trivially easy to do by simply querying for each day in the range separately, but unfortunately that is proving to be an expensive process and therefore slows down horizontal scrolling a lot. So I'm looking for a way to do it more efficiently, hopefully with fewer database reads.
Here is a highly simplified example of the bookings table:
booking_ID | start_Date | end_Date | resource_ID
----------- -------------- ------------- -------------
1 2014-07-17 2014-07-20 21
2 2014-08-24 2014-08-29 4
3 2014-08-26 2014-09-02 21
4 2014-08-28 2014-09-04 19
Ideally, I would like a single query that returns each day within the specified range, along with a count of how many bookings there are on those days. So querying the data above for 20 days from 2014-07-17 would produce this:
check_Date | resources_Used
----------- ---------------
2014-07-17 1
2014-07-18 1
2014-07-19 1
2014-07-20 1
2014-07-21 0
2014-07-22 0
2014-07-23 0
2014-08-24 1
2014-08-25 1
2014-08-26 2
2014-08-27 2
2014-08-28 3
2014-08-29 3
2014-08-30 2
2014-08-31 2
2014-09-01 2
2014-09-02 2
2014-09-03 1
2014-09-04 1
2014-09-05 0
I can get a list of dates in the range by using a table of integers (starting at 0), with this:
SELECT CDATE('2014-07-17') + ID AS check_Date FROM Integers WHERE ID < 20
And I can get the count of resources used for a single day with something like this:
SELECT COUNT(*) AS resources_Used
FROM booking
WHERE start_Date <= CDATE('2014-09-04')
AND end_Date >= CDATE('2014-09-04')
But I can't figure out how (or if) I can tie them both together to get the desired results. Is this even possible?
Create a table called "calendar" and put a list of dates into it covering the necessary timeframe. It just needs one column called check_date with one row for each date. Use Excel, start at whatever date and just drag down, then import into the new table.
After your calendar table is set up you can run the following:
select c.check_date, count(b.resource_id) as resources_used
from calendar c, bookings b
where c.check_date between b.start_date and b.end_date
group by c.check_date
Perhaps my title is misleading, but I am not sure how else to phrase this. I have two tables, tblL and tblDumpER. They are joined based on the field SubjectNumber. This is a one (tblL) to many (tblDumpER) relationship.
I need to write a query that will give me, for all my subjects, a value from tblDumpER associated with a date in tblL. This is to say:
SELECT tblL.SubjectNumber, tblDumpER.ER_Q1
FROM tblL
LEFT JOIN tblDumpER ON tblL.SubjectNumber=tblDumpER.SubjectNumber
WHERE tblL.RandDate=tblDumpER.ER_DATE And tblDumpER.ER_Q1 Is Not Null
This is straightforward enough. My problem is the value RandDate from tblL is different for every subject. However, it needs to be displayed as Day1 so I can have tblDumpER.ER_Q1 as Day1 for every subject. Then I need RandDate+1 As Day2, etc until I hit either null or Day84. The 'dumb' solution is to write 84 queries. This is obviously not practical. Any advice would be greatly appreciated!
I appreciate the responses so far but I don't think that I'm explaining this correctly so here is some example data:
SubjectNumber RandDate
1001 1/1/2013
1002 1/8/2013
1003 1/15/2013
SubjectNumber ER_DATE ER_Q1
1001 1/1/2013 5
1001 1/2/2013 6
1001 1/3/2013 2
1002 1/8/2013 1
1002 1/9/2013 10
1002 1/10/2013 8
1003 1/15/2013 7
1003 1/16/2013 4
1003 1/17/2013 3
Desired outcome:
(Where Day1=RandDate, Day2=RandDate+1, Day3=RandDate+2)
SubjectNumber Day1_ER_Q1 Day2_ER_Q1 Day3_ER_Q1
1001 5 6 2
1002 1 10 8
1003 7 4 3
This data is then going to be plotted on a graph with Day# on the X-axis and ER_Q1 on the Y-axis
I would do this in two steps:
Create a query that gets the MIN date for each SubjectNumber
Join this query to your existing query, so you can perform a DATEDIFF calculation on the MIN date and the date of the current record.
I'm not entirely sure of what it is that you need, but perhaps a calendar table would be of help. Just create a local table that contains all of the days of the year in it, then use that table to JOIN your dates up?