I have the below table in MS Access.
Day ABC
365 25
548 35
730 37
913 58
1095 146
I want to query it such that I get the row before and after a given value of the Day column. This value is variable and can be e.g. value = 432
For this example the query would result the following table.
Day ABC
365 25
548 35
Because the given value = 432 is larger than the Day value of 365 and smaller than the Day value of 548.
What I managed to do is get one field, but not both. The following query gave me correct rows of the Day field.
Select Max(Day) As Day From Table Where Day < 432
UNION
Select Min(Day) As Day From Table Where Day > 432
When I use this code and add another field like ABC I get an error.
You tried to execute a query that does not include the specified
expression 'ABC' as part of an aggregate function.
Could you help me? I think this should be a really easy task. Thank you!
There's a couple of problems with your SQL. The error message occurs because you didn't add a GROUP BY ABC clause to both the SELECT statements.
You'll also get a circular reference as due to MAX(DAY) as DAY - you need to change the as Day to something else maybe as lDay.
You'll probably (I did) get a error Syntax Error calling it Table - pretty sure that's a reserved word.
Maybe this query will work better:
Select Top 1 Day, ABC From Table3 Where Day <= 913 ORDER BY Day Desc
UNION ALL
Select Top 1 Day, ABC From Table3 Where Day >= 913 ORDER BY Day Asc
You could also be a little fancier:
Select Top 2 Day, ABC From Table3 Order By Abs(Day - 432) Desc
Note please, that the result will match the title of the question, not necessarily your detailed explanation ...
Related
Say I have this table:
month
num_of_fruits
harvested
2022-01-01
133
3
2022-02-01
145
12
2022-03-01
123
5
2022-04-01
111
4
2022-05-01
164
9
..
..
..
I want to be able to set a new column called lost based on the month and num_of_fruits columns. To set this lost column, requires a calculation. The calculation is harvested - (num_of_fruits - num_of_fruits(last_month))
I'm having trouble in the parenthesis part - getting the last month's num_of_fruits. I have this to start:
select
id,
"month",
num_of_fruits,
harvested,
harvested - (num_of_fruits - num_of_fruits WHERE date_trunc('month', "month" - interval '1' month)) as lost,
selecting other columns..
It's giving me an error in the where clause.
Can you have a where clause inside a select statement? How would I take the last month's num_of_fruits and subtract it with this month's num_of_fruits - all while inside the select statement?
Any help or advice will greatly help me! Thank you so much in advance!
If you want to check other rows in the table, you will likely want either a subquery in your SELECT or to join the table to itself.
I think you are probably trying to do:
SELECT
harvested - (num_of_fruits - (SELECT num_of_fruits FROM mytable t2 WHERE t2.month = date_trunc('month', t1."month" - interval '1' month))) as lost
FROM mytable t1
Note that I created a whole new subquery (SELECT/FROM/WHERE) within your existing SELECT statement, instead of just adding a stray WHERE clause.
I also changed your condition so that it actually has a compares the result of DATETRUNC with something.
It's not clear to me that you actually need the DATETRUNC here (and, if you do, you might want it on both sides of the comparison), but you can use the basic idea above and fix the condition to match your needs.
An alternative (joining to self) to consider might be:
SELECT
t1.harvested - (t1.num_of_fruits - t2.num_of_fruits)
FROM mytable t1 LEFT OUTER JOIN mytable t2
ON t2.month = date_trunc('month', t1."month" - interval '1' month)))
If you know that you always have one row per month, so the previous row (ordered by month) is also the previous month, you could just use LAG:
SELECT
harvested - (num_of_fruits - LAG(num_of_fruits, 1) OVER (ORDER BY month)
FROM mytable
LAG(num_of_fruits, 1) OVER (ORDER BY month) means "the num_of_fruits from the previous row in the table when the table is ordered by month".
Scratching my head here. I have a very simple postgres table from which I need to select a unique row per day, based solely on a text column which updates as follows.
First update= 'AA1', 2nd update= 'AB', 3rd update= 'D4'
id item date run value
---------------------------------------
23 apple 01/01/16 AA1 232
25 apple 01/01/16 AB 254
26 apple 01/01/16 D4 212
Depending on the time of day, running a query based on the date ('01/01/2016') would return 1, 2 or 3 rows. However I only need the latest row e.g. Run = D4 above.
How can I write a simple select query that always returns just the latest row based of a text based column? I presume i need to create a ranking based on the 'run' column but Im not sure how to do this.
regards
Using the handy distinct on:
select distinct on (date) *
from t
order by date, run desc
I have a list of time-intervals (in seconds) between consecutive datetime-stamped records in a dataset in Access 2010. I want to find the median time interval for each Animal on each Date.
Please can someone tell me how to go about this - either in SQL or VBA?
Example data:
Animal Date Time_interval
1 18/07/14 1
1 18/07/14 18
1 18/07/14 100
1 18/07/14 121
1 18/07/14 156
2 18/07/14 14
2 18/07/14 35
(I also have a field for Time, not included here to keep things simple)
Thanks very much!!
You could run a query with to compare the 2 date/time entries using the DateDiff function.
Here is the setup for DateDiff:
DateDiff ( interval, date1, date2, [firstdayofweek], [firstweekofyear])
From what I understand, create a new query and add a field like this:
median_time_interval: DateDiff ("s", Date, Time)
I have a pretty huge table with columns dates, account, amount, etc. eg.
date account amount
4/1/2014 XXXXX1 80
4/1/2014 XXXXX1 20
4/2/2014 XXXXX1 840
4/3/2014 XXXXX1 120
4/1/2014 XXXXX2 130
4/3/2014 XXXXX2 300
...........
(I have 40 months' worth of daily data and multiple accounts.)
The final output I want is the average amount of each account each month. Since there may or may not be record for any account on a single day, and I have a seperate table of holidays from 2011~2014, I am summing up the amount of each account within a month and dividing it by the number of business days of that month. Notice that there is very likely to be record(s) on weekends/holidays, so I need to exclude them from calculation. Also, I want to have a record for each of the date available in the original table. eg.
date account amount
4/1/2014 XXXXX1 48 ((80+20+840+120)/22)
4/2/2014 XXXXX1 48
4/3/2014 XXXXX1 48
4/1/2014 XXXXX2 19 ((130+300)/22)
4/3/2014 XXXXX2 19
...........
(Suppose the above is the only data I have for Apr-2014.)
I am able to do this in a hacky and slow way, but as I need to join this process with other subqueries, I really need to optimize this query. My current code looks like:
<!-- language: lang-sql -->
select
date,
account,
sum(amount/days_mon) over (partition by last_day(date))
from(
select
date,
-- there are more calculation to get the account numbers,
-- so this subquery is necessary
account,
amount,
-- this is a list of month-end dates that the number of
-- business days in that month is 19. similar below.
case when last_day(date) in ('','',...,'') then 19
when last_day(date) in ('','',...,'') then 20
when last_day(date) in ('','',...,'') then 21
when last_day(date) in ('','',...,'') then 22
when last_day(date) in ('','',...,'') then 23
end as days_mon
from mytable tb
inner join lookup_businessday_list busi
on tb.date = busi.date)
So how can I perform the above purpose efficiently? Thank you!
This approach uses sub-query factoring - what other RDBMS flavours call common table expressions. The attraction here is that we can pass the output from one CTE as input to another. Find out more.
The first CTE generates a list of dates in a given month (you can extend this over any range you like).
The second CTE uses an anti-join on the first to filter out dates which are holidays and also dates which aren't weekdays. Note that Day Number varies depending according to the NLS_TERRITORY setting; in my realm the weekend is days 6 and 7 but SQL Fiddle is American so there it is 1 and 7.
with dates as ( select date '2014-04-01' + ( level - 1) as d
from dual
connect by level <= 30 )
, bdays as ( select d
, count(d) over () tot_d
from dates
left join holidays
on dates.d = holidays.hol_date
where holidays.hol_date is null
and to_number(to_char(dates.d, 'D')) between 2 and 6
)
select yt.account
, yt.txn_date
, sum(yt.amount) over (partition by yt.account, trunc(yt.txn_date,'MM'))
/tot_d as avg_amt
from your_table yt
join bdays
on bdays.d = yt.txn_date
order by yt.account
, yt.txn_date
/
I haven't rounded the average amount.
You have 40 month of data, this data should be very stable.
I will assume that you have a cold body (big and stable easily definable range of data) and hot tail (small and active part).
Next, I would like to define a minimal period. It is a data range that is a smallest interval interesting for Business.
It might be year, month, day, hour, etc. Do you expect to get questions like "what was averege for that account between 1900 and 12am yesterday?".
I will assume that the answer is DAY.
Then,
I will calculate sum(amount) and count() for every account for every DAY of cold body.
I will not create a dummy records, if particular account had no activity on some day.
and I will save day, account, total amount, count in a TABLE.
if there are modifications later to the cold body, you delete and reload affected day from that table.
For hot tail there might be multiple strategies:
Do the same as above (same process, clear to support)
always calculate on a fly
use materialized view as an averege between 1 and 2.
Cold body table totalc could also be implemented as materialized view, but if data never change - no need to rebuild it.
With this you go from (number of account) x (number of transactions per day) x (number of days) to (number of account)x(number of active days) number of records.
That should speed up all following calculations.
I've hit a little snag with one of my queries. I'm throwing together a simple chart to plot a number of reports being submitted by day of week.
My query to start was :
SELECT Weekday(incidentdate) AS dayOfWeek
, Count(*) AS NumberOfIncidents
FROM Incident
GROUP BY Weekday(incidentdate);
This works fine and returns what I want, something like
1 200
2 323
3 32
4 322
5 272
6 282
7 190
The problem is, I want the number returned by the weekday function to read the corresponding day of week, like case when 1 then 'sunday' and so forth. Since Access doesn;t have the SQL server equivalent that returns it as the word for the weekday, I have to work around.
Problem is, it's not coming out the way I want. So I wrote it using iif since I can't use CASE. The problem is, since each iif statement is treated like a column selection (the way I'm writing it), my data comes out unusable, like this
SELECT
iif(weekday(incidentdate) =1,'Sunday'),
iif(weekday(incidentdate) =2,'Monday')
'so forth
, Count(*) AS NumberOfIncidents
FROM tblIncident
GROUP BY Weekday(incidentdate);
Expr1000 Expr1001 count
Sunday 20
Monday 106
120
186
182
164
24
Of course, I want my weekdays to be in the same column as the original query. Halp pls
Use the WeekdayName() function.
SELECT
WeekdayName(Weekday(incidentdate)) AS dayOfWeek,
Count(*) AS NumberOfIncidents
FROM Incident
GROUP BY WeekdayName(Weekday(incidentdate));
As BWS Suggested, Switch was what I wanted. Here's what I ended up writing
SELECT
switch(
Weekday(incidentdate) = 1, 'Sunday',
Weekday(incidentdate) = 2,'Monday',
Weekday(incidentdate) = 3,'Tuesday',
Weekday(incidentdate) = 4,'Wednesday',
Weekday(incidentdate) = 5,'Thursday',
Weekday(incidentdate) = 6,'Friday',
Weekday(incidentdate) = 7,'Saturday'
) as DayOfWeek
, Count(*) AS NumberOfIncidents
FROM tblIncident
GROUP BY Weekday(incidentdate);
Posting this here so there's actual code for future readers
Edit: WeekdayName(weekday(yourdate)) as HansUp said it probably a little easier :)
check this previous post:
What is the equivalent of Select Case in Access SQL?
Why not just create a 7 row table with day number & day name then just join to it?