I am trying to create a subquery in MS Access where the having clause compares a value on the current record. I created the queries separate, but am having a hard time trying to combine them.
I have the following query, which is a Purchase Order list (POsFullDetail), and should show the first occurrence of the date of a PO given the Stock number (Stockum):
SELECT POsFullDetail.PO, POsFullDetail.OrderDate, POsFullDetail.StockNum,
(SELECT First(POsFullDetail.OrderDate) AS FirstOfOrderDate
FROM POsFullDetail
GROUP BY POsFullDetail.StockNum
HAVING POsFullDetail.StockNum = POsFullDetail.StockNum.Value
ORDER BY First(POsFullDetail.OrderDate)
) AS First_Date
FROM POsFullDetail;
The statement that I am trying to work with is POsFullDetail.StockNum.Value
The way it is set up, it's asking for a value. When I created the subquery separate I entered the stock number directly.
The subquery gives you the first order date per stocknum.
When using it as a subquery, you are no longer interested in the first order date per stocknum, but in the first order date for the stocknum.
SELECT POsFullDetail.PO, POsFullDetail.OrderDate, POsFullDetail.StockNum,
(
SELECT First(SameStockNum.OrderDate) AS FirstOfOrderDate
FROM POsFullDetail AS SameStockNum
WHERE SameStockNum.StockNum = POsFullDetail.StockNum
) AS First_Date
FROM POsFullDetail;
As you see, you must use a table alias, so you can link the table to itself. Though working with the same table you call it one time POsFullDetail and one time SameStockNum which enables you to link by SameStockNum.StockNum = POsFullDetail.StockNum.
Related
I am struggling with a SQL query.
My query looks something like this:
Select
Count(user-id),
sum(distinct(date),
Sum(characters-posted)
From (
Select
Date,
User-Id,
Session-Id,
Characters—posted,
Variant-id
From database-name
Where date between ‘2022-09-01’ and ‘2022-09-31’)
This works ok. But, there is another field in the table “mailing-list”, which is just 0 or 1. I want to only get activity for members from the date when they join the mailing list onwards, even if they then leave the list, so can’t just do “where mailing-list=1”.
How can I do this?
It's not obvious what works fine for you as it seems to be uncommon to sum dates, given it is a regular date format. Are you trying to get number of active dates? as for the bottom question you might.
As for your buttom line quesiton, it seems that you might want to use a cte or subselect in a join.
your query...
from db_name dbn
inner join (select user_id, min(date) date from database_name
where mailing_list = 1 group by 1) start_date
on start_date.user_id = dbn.user_id
and start_date.date <= dbn.date
That way you're only getting activity starting from the first time your users join the mailing list.
But I still think you have an error in your final query, check it out.
I am trying to assign a specific code to a client based on the number of gifts that they have given in the past 6 months using a CASE. I am unable to use WITH (screenshot) due to the limitations of the software that I am creating the query in. It only allows for select functions. I am unsure how to get a distinct count from another table (transaction data) and use that as parameters in the CASE I have currently built (based on my client information table). Does anyone know of any workarounds for this? I am unable to GROUP BY clientID at the end of my query because not all of my columns are aggregate, and I only need to GROUP BY clientID for this particular WHEN statement in the CASE. I have looked into the OVER() clause, but I am needing my date range that I am evaluating to be dynamic (counting transactions over the last six months), and the amount of rows that I would be including is variable, as the transaction count month to month varies. Also, the software that I am building this in does not recognize the PARTITIONED BY parameter of the over clause.
Any help would be great!
EDIT:
it is not letting me attach an image... -____- I have added the two sections of code that I am looking for assistance with!
WITH "6MonthGIftCount" (
"ConstituentID"
,"GiftCount"
)
AS (
SELECT COUNT(DISTINCT "GiftView"."GiftID" FROM "GiftView" WHERE MONTHS_BETWEEN("GiftView"."GiftDate", getdate()) <= 6 GROUP BY "GiftView"."ConstituentID")
SELECT...CASE
WHEN "6MonthGiftCount"."GiftCount" >= 4
THEN 'A010'
)
Perform your grouping/COUNT(1) in a subquery to obtain the total # of donations by ConstituentID, then JOIN this total into your main query that uses this new column to perform its CASE statement.
select
hist.*,
case when timesDonated > 5 then 'gracious donor'
when timesDonated > 3 then 'repeated donor'
when timesDonated >= 1 then 'donor'
else null end as donorCode
from gifthistory hist
left join ( /* your grouping subquery here, pretending to be a new table */
select
personID,
count(1) as timesDonated
from gifthistory i
WHERE abs(months_between(giftDate, sysdate)) <= 6
group by personid ) grp on hist.personid = grp.personID
order by 1;
*Naturally, syntax changes will vary by DB; you didn't specify which it was based on, but you should be able to use this template with whichever you utilize. This works in both Oracle and SQL Server after tweaking the month calculation appropriately.
I have a view in SQL Server with prices of items over time. My users will be passing a date variable and I want to return the closest record without going over, or if no such record exists return the oldest record present. For example, with the data below, if the user passes April for item A it will return the March record and for item B it will return the June record.
I've tried a lot of variations with Union All and Order by but keep getting a variety of errors. Is there a way to write this using a Case Statement?
example:
case when min(Month)>Input Date then min(Month)
else max(Month) where Month <= Input Date?
Sincere apologies for attaching sample dataset as an image, I couldn't get it to format right otherwise.
Sample Dataset
You can use SELECT TOP (1) with order by DATE DESC + Item type + date comparison to get the latest. ORDER BY will order records by date, then you get the latest either this month (if exists) or earlier months.
Here's a rough outline of a query (without more of your table it's hard to be exact):
WITH CTE AS
(
SELECT
ITEM,
PRICE,
MIN(ACTUAL_DATE) OVER (PARTITION BY ITEM ORDER BY ITEM) AS MIN_DATE,
MAX(INPUT_DATE<=ACTUAL_DATE) OVER (PARTITION BY ITEM ORDER BY ITEM,ACTUAL_DATE) AS MATCHED_DATE
FROM TABLE
)
SELECT
CTE.ITEM,
CTE.PRICE,
CASE
WHEN
CTE.MATCHED_DATE IS NOT NULL
THEN
CTE.MATCHED_DATE
ELSE
CTE.MIN_DATE
END AS MOSTLY_MATCHED_DATE
FROM CTE
GROUP BY
CTE.ITEM,
CTE.PRICE
The idea is that in a Common Table Expression, you use the PARTITION BY function to identify the key date for each item, record by record, and then you do a test in aggregate to pull either your matched record or your default record.
I have a SQL statement that I am currently using to return a number of rows from a database:
SELECT
as1.AssetTagID, as1.TagID, as1.CategoryID,
as1.Description, as1.HomeLocationID, as1.ParentAssetTagID
FROM Assets AS as1
INNER JOIN AssetsReads AS ar ON as1.AssetTagID = ar.AssetTagID
WHERE
(ar.ReadPointLocationID='Readpoint1' OR ar.ReadPointLocationID='Readpoint2')
AND (ar.DateScanned between 'LastScan' AND 'Now')
AND as1.TagID!='000000000000000000000000'
I am wanting to do a query that will get the row with the oldest DateScanned from this query and also get another row from the database if there was one that was within a certain period of time from this row (say 5 seconds for an example). The oldest record would be relatively simple by selecting the first record in a descending sort, but how would I also get the second record if it was within a certain time period of the first?
I know I could do this process with multiple queries, but is there any way to combine this process into one query?
The database that I am using is SQL Server 2008 R2.
Also please note that the DateScanned times are just placeholders and I am taking care of that in the application that will be using this query.
Here is a fairly general way to approach it. Get the oldest scan date using min() as a window function, then use date arithmetic to get any rows you want:
select t.* -- or whatever fields you want
from (SELECT as1.AssetTagID, as1.TagID, as1.CategoryID,
as1.Description, as1.HomeLocationID, as1.ParentAssetTagID,
min(DateScanned) over () as minDateScanned, DateScanned
FROM Assets AS as1
INNER JOIN AssetsReads AS ar ON as1.AssetTagID = ar.AssetTagID
WHERE (ar.ReadPointLocationID='Readpoint1' OR ar.ReadPointLocationID='Readpoint2')
AND (ar.DateScanned between 'LastScan' AND 'Now')
AND as1.TagID!='000000000000000000000000'
) t
where datediff(second, minDateScanned, DateScanned) <= 5;
I am not really sure of sql server syntax, but you can do something like this
SELECT * FROM (
SELECT
TOP 2
as1.AssetTagID,
as1.TagID,
as1.CategoryID,
as1.Description,
as1.HomeLocationID,
as1.ParentAssetTagID ,
ar.DateScanned,
LAG(ar.DateScanned) OVER (order by ar.DateScanned desc) AS lagging
FROM
Assets AS as1
INNER JOIN AssetsReads AS ar
ON as1.AssetTagID = ar.AssetTagID
WHERE (ar.ReadPointLocationID='Readpoint1' OR ar.ReadPointLocationID='Readpoint2')
AND (ar.DateScanned between 'LastScan' AND 'Now')
AND as1.TagID!='000000000000000000000000'
ORDER BY
ar.DateScanned DESC
)
WHERE
lagging IS NULL or DateScanned - lagging < '5 SECONDS'
I have tried to sort the results by DateScanned desc and then just the top most 2 rows. I have then used the lag() function on DateScanned field, to get the DateScanned value for the previous row. For the topmost row the DateScanned shall be null as its the first record, but for the second one it shall be value of the first row. You can then compare both of these values to determine whether you wish to display the second row or not
more info on the lagging function: http://blog.sqlauthority.com/2011/11/15/sql-server-introduction-to-lead-and-lag-analytic-functions-introduced-in-sql-server-2012/
We have a ERP that integrates nicely with Crystal Reports.
Now, we can add filters through this application, and it passes these to the report (not as parameters but somehow adds this to the WHERE clause).
The problem is, when filtering dates, we have no way in the report to determine what date range the user selected (as we want to show this date on the report).
Any idea how I can show this through SQL?
I was thinking of using the dual table, and selecting a huge list of dates, then using the MIN and MAX of these dates to determine which was selected. The problem is, I can't join this onto my original query without adding LOTS of rows.
I have this so far:
SELECT
MIN(DTE) MIN_DTE,
MAX(DTE) MAX_DTE
FROM
(
SELECT
TRUNC(SYSDATE)-(5*365) + ROWNUM AS DTE
FROM
DUAL
CONNECT BY
ROWNUM <= (10*365)
)
WHERE
DTE >= '12-NOV-07'
AND DTE <= '12-DEC-07'
But the problem is I can't work out how to join that to my original query without upsetting the row cont.
Any other ideas?
That query returns only one row, so it won't upset the row count at all, unless there is something else going on (like, maybe, the automatic filtering doesn't work in subqueries).
Otherwise, this should work as expected:
SELECT q.*, max_min.*
FROM ( ... put your original query here ...) q,
( ... put the subquery that returns one row with max & min here ...) max_min
That's all to it.