I am having trouble calculating differences between two rows. The current query is as follow
Sessiontype Question Average
Admission Question 1 2.25
Discharge Question 1 4.25
I need to calculate discharge average - admission average for question 1. Note this is just a snipplet of the query, there are actually 5 questions. So the problem is I am unsure how to approach it in MS Access .
Related
I'm trying to obtain the average time of an "activity" in a moodle database, i am not an sql expert, but i have managed to get to the point showed in the picture, my question is if exists a way to obtain, first the timestamp/time difference (this "activity" does not have a starting time column like many others) by day and then sum them all to get the average of that activity , for the first i tried with the function 'EXTRACT()' and comparing the dates in the format "%Y-%m-%d" but only sums the first row where they are equal, by the way i have been doing this just by a sql statement, i know the existence of store procedures but my level of sql is not that high.
Thanks in advance!
data obtained so far
Data on table logs (the most important i think)
component
action
objecttable
userid
courseid
timecreated
mod_quiz*
viewed
quiz_attempts
6
2
1645287525
mod_forum
viewed
forum
5
2
1645288525
core
loggedout
user
2
0
1645291745
mod_page
viewed
page
5
2
1645291955
Data i've trying to get:
Activity
StartTime
EndTime
Total
forum
19:01
19:10
9 minute(s)
quiz
15:45
16:00
15 minute(s)
page
...
...
...
workshop
...
...
...
but so far i get to assort the data in a column
Time
2022-x-x h:m
....
but when i try to sum by day with the function EXTRACT() and trying to match the dates in a very long query it just get the first record.
NOTE: * half of the "activities" were easy to calculate since they have a "timestart" and "timeend" columns but i can not figure out how to solve the ones that do not have a "timestart" column.
I'm trying to use data that is labeled by year (2012 - 2016) to calculate CAGR. The data was originally in one column indicating the total population with another column indicating the year. I've isolated the 2012 and 2016 data into two separate columns and am trying to use SQL to calculate the CAGR rate ((data from 2016)/(data from 2012)^(1/4))-1.
Is this the correct way to calculate CAGR/cummulative growth? I've tried simply using the two columns of data but because they are mismatched and have nulls, it doesn't work. Please let me know if you have any ideas.
Compound Annual Growth Rate (CAGR) doesn't really lend itself to what you're trying to do.
Usually this is used when you say, invest $1000 in a fund, and you calculate the annual growth based on the ending value.
Example - if you invest $1000 and in 5 years it's worth $5000:
( 5,000 / 1,000)1/5 - 1 = .37973 = 37.97%
If I was to write that in SQL Server it would be:
SELECT SUM(POWER((5000.0/1000.0),(1.0/5.0))-1.0)
You can replace the 5000 and 1000 to be the specific columns you want to compare, or a range of data you need to compare.
If you elaborate your question I will update this answer.
I have a database with 169461 records. Within one field is begin_milepost that numerically counts up from 0 at 0.01 intervals. I want to change the interval from 0.01 to 0.1 by making a new column that averages ten records at a time to create one record, and having it do this all the way down. I'm using access 2013.
Example would be 0.01,0.02,0.03,0.04,0.05,0.06,0.07,0.08,0.09,0.1 being turned into 0.055 and repeating on the next ten records.
See if this gives you what you are looking for:
SELECT (([Marker]-0.01)*100)\10 AS MarkerGroup, Sum([Marker])/Count([Marker]) AS AvgMarker
FROM tblMarkers
GROUP BY (([Marker]-0.01)*100)\10;
I have two database in SQL Server. I wanted to find out the data older than (let say 3) years.
I know the database creation date, currently I have around 550 GB (both the database) of data spanned for 7 years, I wanted to know 'how much of the DB data (out of total 550 GB)is older than 3 years OR (5 years)'?
I was going through this link but couldn't get the expected data.
SQL SERVER – Query to find number Rows, Columns, ByteSize for each table in the current database – Find Biggest Table in Database
One of the solution coming in my mind right now is to find out the total number of rows accounted for 7 years (easily get this number), total number of rows accounted for 5 years (starting from the date creation) (don't know how to get this number).
then for row_count_7_years accounts for 550 GB of data , what will be the row_count_5_years? i will get the approx data.
Please Help
For such purposes you should keep some datetime field as marc mentioned. I suppose you don't have it.
In you suggested solution you can get the whole count of rows from your table (for 7 years i suppose), but you wouldn't be able to get the rows for 5 years, because there is no date.
You can get the whole number of records for 7 years and divide them on the number of years, and ONLY IN CASE you have your database avarage fulfill, you can make query for top (numberOFRows in one year)*5 and order them by row_number(). The result - the rows, you should delete. But I wouldn't recommend you to use this solution.
I would recommend you to alter your tables and add the datetime columns for each of them. Before that you should make the backup for the whole date and copy it somewhere. After 3 years you would be able to make your clean up.
as mentioned above u shud have a date column , however if you dont , depending on the realtionships in your tables u might be able to estimate the number of rows looking up realtionships with some other table that has the datetime column , else if you have a backup ( unlikely but still) you can restore that to identify the delta
Suppose ,I have a table which has all the billing records. Now I want to see the sales trend for a user given time duration group by each 3 days ...what should be the sql query regarding this?
please help,Otherwise I am gone ...
I can only give a vague suggestion as per the question, however you may want to have a derived column with a standardised date (as per MS date format, just a number per day) that you could then use a modulus (3) on so that days are equal per 3 day period. You can then group and aggregate over this column to get the values for a 3 day period. Obviously to display the date nicely you would have to multiply back and convert your column as well.
Again I'm not sure of the specifics, but I think this general idea could be achieved to get a result (may well not be the best way so it would help to add more to the question...)