Reference Date 2 Months Prior Access SQL - sql

I'm doing a Self Join, but having trouble doing it with dates. I have a date column, mm/dd/yyyy in intervals of a month (1/1/2006, 2/1/2006,...) and a number column of a variety of numbers. See code below...
SELECT t.ADate,
Sum(pre.liquid)/3 AS IP90
FROM [Table2] t
LEFT JOIN [Table2] pre ON pre.ADate >= (t.ADate -3)
AND pre.ADate <= t.ADate
GROUP BY t.ADate;
I'm taking the average of the records 2 months prior to the current date and the current date. So, for 5/1/2006 I want the average amount of liquid for 3/1/2006, 4/1/2006, and 5/1/2006. How can I do that in my code? Thank you.

Can you specify the dates in the query? Also I believe there is an average function in Access.
SELECT AVG(pre.liquid) As IP90
FROM [Table2] t
LEFT JOIN [Table2] pre
ON pre.ADate = t.ADate
WHERE t.ADate BETWEEN '3/1/2006' AND '5/1/2006';
Note you might have to give the dates a bit of leeway depending on the date values.

Related

trouble joining two date tables with consecutive dates starting at customer create date and ending at current date?

I am creating a customer activity by day table, which requires 9 CTEs.
The first table I want to cross join all customer unique IDs with the dates of a calendar table. So there will be multiple rows with the same unique ID for each day.
The problem is making sure the days are consecutive, regardless of the dates in the following CTEs.
This is a shortened example of what it would look like this:
GUID DATE CONDITIONS
1 3/13/2015 [NULL]
1 3/14/2015 Y
1 3/15/2015 [NULL]
....
1 9/2/2020 Y
2 4/15/2015 Y
2 4/16/2015 [NULL]
2 4/17.2015 [NULL]
2 4/18/2015 Y
...
2 9/2/2020 [NULL]
And so on - so that each customers has consecutive dates with their GUID, beginning with the creation date of their account (i.e. 3/13/2015) and ending on the current date.
the create date is on Table 1 with the unique ID, and I'm joining it with a date table.
My problem is that I can't get the query to run with a minimum create date per unique ID. Because if I don't create a minimum start date, the query runs forever (it's trying to create every unique ID for every consecutive date, even before the customer account was created.)
This is the code I have now.
Can anyone tell me if I have made the min. create date right? It's still just timing out when I run the query.
with
cte_carrier_guid (carrier_guid, email, date, carrier_id) as
(
SELECT
guid as carrier_guid
,mc.email
,dt2.date as date
,mc.id as carrier_id
FROM ctms_db_public.msd_carrier mc
CROSS JOIN public.dim_calendar dt2
WHERE dt2.date <= CURRENT_DATE
AND mc.created_at >= dt2.date
GROUP BY guid, mc.id, dt2."date", mc.email
ORDER BY guid, dt2.date asc
)
Select top 10 * from cte_carrier_guid
Here:
dt2.date <= CURRENT_DATE AND mc.created_at >= dt2.date
Since you want dates between the creation date of the user and today, you probably want the inequality condition on the creation date the other way around. I find it easier to follow when we put the lower bound first:
dt2.date >= mc.created_at AND dt2.date <= CURRENT_DATE
Other things about the query:
You want an INNER JOIN in essence, so use that instead of CROSS JOIN ... WHERE; it is clearer
ORDER BY in a cte makes no sense to me
Do you really need GROUP BY? The columns in the SELECT clause are the same as in the GROUP BY, so all this does is remove potential duplicates (but why would there be duplicates?)
You could probably phrase the cte as:
SELECT ...
FROM ctms_db_public.msd_carrier mc
INNER JOIN public.dim_calendar dt2 ON dt2.date >= mc.created_at
WHERE dt2.date <= CURRENT_DATE

Can someone help me with this join

I need it to give me me a total of 0 for week 33 - 39, but I'm really bad with joining 3 tables and I cant figure it out
Right now it only gives me an answer for dates that there are actual records in the tracker_weld_table.
SELECT SUM(tracker_parts_archive.weight),
WEEK(mycal.dt) as week
FROM
tracker_parts_archive, tracker_weld_archive
RIGHT JOIN
(SELECT dt FROM calendar_table WHERE dt >= '2018-7-1' AND dt <= '2018-10-1') as mycal
ON
weld_worker = '133'AND date(weld_dateandtime) = mycal.dt
WHERE
tracker_weld_archive.tracker_partsID = tracker_parts_archive.id
GROUP BY week
I think you are trying for something like this:
SELECT WEEK(c.dt) as week, COALESCE(SUM(tpa.weight), 0)
FROM calendar_table c left join
tracker_weld_archive tw
on date(tw.weld_dateandtime) = c.dt left join
tracker_parts_archive tp
on tw.tracker_partsID = tp.id and tp.weld_worker = 133
WHERE c.dt >= '2018-07-01' AND c.dt <= '2018-10-01'
GROUP BY week
ORDER BY week;
Notes:
You want to keep all (matching) rows in the calendar table, so it should be first.
All subsequent joins should be LEFT JOINs.
Never use commas in the FROM clause. Always use proper, explicit, standard JOIN syntax.
Write out the full proper date constant -- YYYY-MM-DD. This is an ISO-standard format.
I am guessing that weld_worker is a number, so single quotes are not needed for the comparison.
First, lets start with understanding what you want.. You want totals per week. This means there will be a "GROUP BY" clause (also for any MIN(), MAX(), AVG(), SUM(), COUNT(), etc. aggregates). What is the group BY basis. In this scenario, you want per week. Leading to the next part that you want for a specific date range qualified per your calendar table.
I would start in order what WHAT filtering criteria first. Also, ALWAYS TRY to identify all table( or alias).column in your queries so anyone after you knows where the columns are coming from, especially when multiple tables. In this case "ct" is the ALIAS for "Calendar_Table"
SELECT
ct.dt
from
calendar_table ct
where
ct.dt >= '2018-07-01'
AND ct.dt <= '2018-10-01'
Now, the above date looks to be INCLUSIVE of October 1 and looks like you are trying to generate a quarterly sum from July, Aug, Sept. I would change to LESS than Oct 1.
Now, your calendar has many days and you want it grouped by week, so the WEEK() function gets you that distinct reference without explicitly checking every date. Also, try NOT to use reserved keywords as final column names... makes for confusion later on sometimes.
I have aliased the column name as "WeekBasis". Here, I did a COUNT(*) just to show the total days and the group by showing it in context.
SELECT
WEEK( ct.dt ) WeekBasis,
MIN( ct.dt ) as FirstDayOfThisWeek,
MAX( ct.dt ) as LastDayOfThisWeek,
COUNT(*) as DaysInThisWeek
from
calendar_table ct
where
ct.dt >= '2018-07-01'
AND ct.dt <= '2018-10-01'
group by
WEEK( ct.dt )
So, at this point, we have 1 record per week within the date period you are concerned,
but I also grabbed the earliest and latest dates just to show other components too.
Now, lets get back to your extra tables. We know the dates in question, now need to
get the details from the other tables (which is lacking in the post. You should post
critical components such as how tables are related via common / joined column basis.
How is tracker_part_archive related to tracker_weld_archive??
To simplify your query, you dont even NEED your calendar table as the welding
table HAS a date field and you know your range. Just query against that directly.
IF your worker's ID is numeric, don't add quotes around it, just leave as a number.
SELECT
WEEK( twa.Weld_DateAndTime ) WeekBasis,
COUNT(*) WeldingEntriesDone,
SUM(tpa.weight) TotalWeight
from
tracker_weld_archive twa
JOIN tracker_parts_archive tpa
-- GUESSING on therelationship here.
-- may also be on a given date too???
-- all pieces welded by a person on a given date
ON twa.weld_worker = tpa.weld_worker
AND twa.Weld_DateAndTime = tpa.Weld_DateAndTime
where
twa.Weld_Worker = 133
AND twa.Weld_DateAndTime >= '2018-07-01'
AND twa.Weld_DateAndTime <= '2018-10-01'
group by
WEEK( twa.Weld_DateAndTime )
IF you provide the table structures AND sample data, this can be refined a bit more for you.

How to calculate difference between two rows in a date interval?

I'm trying to compare data from an Access 2010 database based on a date interval. Example I have items from various purchase orders and I want to maintain the history of these item's delivery to a warehouse. So my purchase order has a request for a quantity of 10 of a material, for example, and it can be partially delivered in many deliveries and I want to know how this delivery varied in a date interval. To fill the date field the criteria used is the following: if the item had an update in the QtyPending field, I copy the current row deactivating it with a booelan field, create a new entry with the current update date updating the QtyPending field, so the active record is the actual state of the item. So I have a table that holds informations about these items like that
PO POItem QtyPending Date Active
4500000123 10 10 01/09/2014 FALSE
4500000123 10 8 05/09/2014 TRUE
4500000122 30 5 03/09/2014 FALSE
4500000122 30 1 04/09/2014 TRUE
With this example, for the first item, it means that from date 01/09 to 04/09 the QtyPending field didn't suffer a variation, meaning that the supplier didn't make any delivery to me, but from 01/09 to 05/08 he delivered me a qty of 2 of a material. For the second one, from date 03/09 to 04/09 the supplier delivered me a qty of 4 of a material. So, if I were to be making a report query from 02/09/2014 to 04/09/2014, the expected output is like this:
PO POItem QtyDelivered
4500000123 10 0
4500000122 30 4
And a report from 31/08/2014 to 10/09/2014, would have this output
PO POItem QtyDelivered
4500000123 10 2
4500000122 30 4
I'm not coming up with a query to make this report. Can anyone help me?
There are many ways of solving this. The easiest one would be to simply make a query of all the necessary records between two dates, loop over them and insert into a temporary table the result. This temporary table can then be the source of your report. A lot of people will scream at you for not using a big query instead but getting the result that you want in the fastest and simplest way should be your priority.
Your problem with your schema is that you don't have the QtyDelivered stored for each record. If you would have it, it would be an easy thing to sum over it in order to get needed result. By not storing this value, you have transformed a simple and fast query into a much harder and slower one because you need to recalculate this value in some way or other and you must do this without forgetting the fact that it's possible to have more than two records.
For calculating this value, you can either use a sub-query to retrieve the value from the previous row or a Left join do to the same. Once you have this value, you can subtract these two to get the needed difference; allowing for the possibility of Null value if there is no previous row. Once you have these values, you can now sum over them to get the final result with a Group By. Notice that in order to perform these calculations, you need to have one or two more levels of subquery. The first query should be something like:
Select PO, POItem, QtyPending, (Select Top 1 QtyPending from MyTable T2 where T1.PO = T2.PO and T2.Date < T1.Date And (T2.Date between #Date1 and #Date2) Order by T2.Date Desc) as QtyPending2 from MyTable T1 Where T1.Date between #Date1 and #Date2) ...
With this as either another subquery or as a View, you can then compute the desired difference by comparing the values of QtyPending and QtyPending2; without forgetting that QtyPendin2 may be Null. The remaining steps are easy to do.
Notice that the above example is for SQL-Server, you might have to change it a little for Access. In any case, you can find here many examples on how to compare two rows under Access. As noted earlier, you can also use a Left Join instead of a subquery to compare your rows.
I came up with this query that solved the problem, it wasn't that simple
SELECT
ItmDtIni.PO
,ItmDtIni.POItem AS [PO Item]
,ROUND(ItmDtIni.QtyPending - ItmDtEnd.QtyPending, 3) AS [Qty Delivered]
,ROUND((ItmDtIni.QtyPending - ItmDtEnd.QtyPending) * ItmDtEnd.Price, 2) AS [Value delivered(US$)]
//Filtering subqueries to bring only the items in the date interval to make a self join
FROM (((SELECT
PO
,POItem
,QtyPending
,MIN(Date) AS MinDate
FROM Item
WHERE Date BETWEEN FORMAT(begin_date, 'dd/mm/yyyy') AND FORMAT(end_date, 'dd/mm/yyyy')
GROUP BY
PO
,POItem
,QtyPending) AS ItmDtIni
//Self join filtering to bring only items in the date interval with the previously filtered table
INNER JOIN (SELECT
PO
,POItem
,QtyPending
,Price
,MAX(Date) AS MaxDate
FROM Item
WHERE Date BETWEEN FORMAT(begin_date, 'dd/mm/yyyy') AND FORMAT(end_date, 'dd/mm/yyyy')
GROUP BY
PO
,POItem
,QtyPending
,Price) AS ItmDtEnd
ON ItmDtIni.PO = ItmDtEnd.PO
AND ItmDtIni.POItem = ItmDtEnd.POItem)
INNER JOIN PO
ON ItmDtEnd.PO = PO.Numero)
WHERE
//Showing only items that had a variation in the date interval
ROUND(ItmDtIni.QtyPending - ItmDtEnd.QtyPending, 3) <> 0
//Anchoring min date in the interval for each item found by the first subquery
AND ItmDtIni.MinDate = (SELECT MIN(Item.Date)
FROM Item
WHERE
ItmDtIni.PO = Item.PO
AND ItmDtIni.POItem = Item.POItem
AND Date BETWEEN FORMAT(begin_date, 'dd/mm/yyyy') AND FORMAT(end_date, 'dd/mm/yyyy'))
//Anchoring max date in the interval for each item found by the second subquery
AND ItmDtEnd.MaxDate = (SELECT MAX(Item.Date)
FROM Item
WHERE
ItmDtEnd.PO = Item.PO
AND ItmDtEnd.POItem = Item.POItem
AND Date BETWEEN FORMAT(begin_date, 'dd/mm/yyyy') AND FORMAT(end_date, 'dd/mm/yyyy'))

How to have GROUP BY and COUNT include zero sums?

I have SQL like this (where $ytoday is 5 days ago):
$sql = 'SELECT Count(*), created_at FROM People WHERE created_at >= "'. $ytoday .'" AND GROUP BY DATE(created_at)';
I want this to return a value for every day, so it would return 5 results in this case (5 days ago until today).
But say Count(*) is 0 for yesterday, instead of returning a zero it doesn't return any data at all for that date.
How can I change that SQLite query so it also returns data that has a count of 0?
Without convoluted (in my opinion) queries, your output data-set won't include dates that don't exist in your input data-set. This means that you need a data-set with the 5 days to join on to.
The simple version would be to create a table with the 5 dates, and join on that. I typically create and keep (effectively caching) a calendar table with every date I could ever need. (Such as from 1900-01-01 to 2099-12-31.)
SELECT
calendar.calendar_date,
Count(People.created_at)
FROM
Calendar
LEFT JOIN
People
ON Calendar.calendar_date = People.created_at
WHERE
Calendar.calendar_date >= '2012-05-01'
GROUP BY
Calendar.calendar_date
You'll need to left join against a list of dates. You can either create a table with the dates you need in it, or you can take the dynamic approach I outlined here:
generate days from date range

Confused on count(*) and self joins

I want to return all application dates for the current month and for the current year. This must be simple, however I can not figure it out. I know I have 2 dates for the current month and 90 dates for the current year. Right, Left, Outer, Inner I have tried them all, just throwing code at the wall trying to see what will stick and none of it works. I either get 2 for both columns or 180 for both columns. Here is my latest select statement.
SELECT count(a.evdtApplication) AS monthApplicationEntered,
count (b.evdtApplication) AS yearApplicationEntered
FROM tblEventDates a
RIGHT OUTER JOIN tblEventDates b ON a.LOANid = b.loanid
WHERE datediff(mm,a.evdtApplication,getdate()) = 0
AND datediff(yy,a.evdtApplication, getdate()) = 0
AND datediff(yy,b.evdtApplication,getdate()) = 0
You don't need any joins at all.
You want to count the loanID column from tblEventDates, and you want to do it conditionally based on the date matching the current month or the current year.
SO:
SELECT SUM( CASE WHEN Month(a.evdtApplication) = MONTH(GEtDate() THEN 1 END) as monthTotal,
count(*)
FROM tblEventDates a
WHERE a.evdtApplication BETWEEN '2008-01-01' AND '2008-12-31'
What that does is select all the event dates this year, and add up the ones which match your conditions. If it doesn't match the current month it won't add 1. Actually, don't even need to do a condition for the year because you're just querying everything for that year.