UPDATE: yes, the result is for a single record. I want to put this on a "computed by" field in firebird (PRODUCTS.PRODU_AVGCOST). It just takes the last 3 buyings for a product and calculates the average cost of it.
I have three tables, witch follows the revelant fields:
PRODUCTS
PRODU_ID PK,
PRODU_AVGCOST calculated
BUYINGS
BUYIN_ID PK
BUYING_ITENS
ITEN_ID PK,
ITEN_BUYING_ID FK
ITEN_COST numeric
I want to take the average cost of last three buyings from ITEN_COST field, using "select" for the PRODU_AVGCOST field of the PRODUCTS table
I tried as follows on table PRODUCTS, but this didn't work
select avg(iten_cost) from buying_itens b
where (select first 3 (iten_cost) from buying_itens where c.iten_id = produ_id)
order by b.iten_id desc
Assuming you want this for a single product (assuming ACTUAL_PRODU_ID is that value), you can do:
select avg(a.iten_cost)
from (
select first 3 iten_cost
from buying_itens
where produ_id = ACTUAL_PRODU_ID
order by iten_id desc
) a
As far as I can tell the datamodel in your question is not complete (or I fail to see how products and buying_itens are linked), so I have 'added' produ_id to buying_itens.
If you want to do this for all products in a single query, things get more complicated.
Related
I'm having trouble understanding this error through all the researching I have done. I have the following query
SELECT M.[PO Concatenate], Sum(M.SumofAward) AS TotalAward, (SELECT TOP 1 M1.[Material Group] FROM
[MGETCpreMG] AS M1 WHERE M1.[PO Concatenate]=M.[PO Concatenate] ORDER BY M1.SumofAward DESC) AS TopGroup
FROM MGETCpreMG AS M
GROUP BY M.[PO Concatenate];
For a brief instance it reviews the results I want, but then the "At most one record can be returned by this subquery" error comes and wipes all the data to #Name?
For context, [MGETCpreMG] is a query off a main table [MG ETC] that was used to consolidate Award for differing Material Groups on a PO transaction ([PO Concatenate])
SELECT [MG ETC].[PO Concatenate], Sum([MG ETC].Award) AS SumOfAward, [MG ETC].[Material Group]
FROM [MG ETC]
GROUP BY [MG ETC].[PO Concatenate], [MG ETC].[Material Group]
ORDER BY [MG ETC].[PO Concatenate];
I'm thinking it lies in my inability to understand how to utilize a subquery.
In the case in which the query can return more then one value? Simply add an additonal sort by.
So, a common sub query might be to get the last invoice. So you might have:
select ID, CompanyName,
(SELECT TOP 1 InvoiceDate from tblInvoice
where tblInvoice.CustomerID = tblCompany.ID
Order by InvoiceDate DESC)
As LastInvoiceDate
From tblCustomers
Now the above might work for some time, but then it will blow up since you might have two invoices for the same day!
So, all you have to do is add that extra order by clause - say on the PK of the child table like this:
Order by InvoiceDate DESC,ID DESC)
So top 1 will respect the "additional" order columns you add, and thus only ever return one row - even if there are multiple values that match the top 1 column.
I suppose in the above we could perhaps forget the invoiceDate and always take the top most last autonumber ID, but for a lot of queries, you can't always be sure - it might be we want the last most expensive invoice amount. And again, if the max value (top) was the same for two large invoice amounts, then again two rows could be return. So, simply add the extra ORDER BY clause with an 2nd column that further orders the data. And thus top 1 will only pull the first value. Your example of a top group is such an example. Just tack on the extra order by "ID" or whatever the auto number ID column is.
On a report builder 3.0, i retreived some items and counted them using a Count aggregate. Now i want to order them from highest to lowest. How do i use the ORDER BY function on the aggregated column? The picture below show the a column that i want to ORDER BY it, it is ticked.
Pic
The code is vers simple as shown bellow:
SELECT DISTINCT act_id,NameOfAct,
FROM Acts
Your picture indicates you also want a Total row at the bottom:
SELECT
COALESCE(NameOfAct,'Total') NameOfAct,
COUNT(DISTINCT act_id) c
FROM Acts
GROUP BY ROLLUP(NameOfAct)
ORDER BY
CASE WHEN NameOfAct is null THEN 1 ELSE 0 END,
c DESC;
Result of example data:
NameOfAct count
-------------- -------
Act_B 3
Act_A 2
Act_Z 1
Total 6
Try it with example rows at: http://sqlfiddle.com/#!18/dbd6c/2
I looked at the Pic. So you might have duplicate acts with the same name. And you want to know the number of acts that have the same unique name.
You might want to group the results by name:
GROUP BY NameOfAct
And include the act names and their counts in the query results:
SELECT NameOfAct, COUNT(*) AS ActCount
(Since the act_id column is not included in the groups, you need to omit it in the SELECT. The DISTINCT is also not necessary anymore, since all groups are unique already.)
Finally, you can sort the data (probably descending to get the acts with the largest count on top):
ORDER BY ActCount DESC
Your complete query would become something like this:
SELECT NameOfAct, COUNT(*) AS ActCount
FROM Acts
GROUP BY NameOfAct
ORDER BY ActCount DESC
Edit:
By the way, you use field "act_id" in your SELECT clause. That's somewhat confusing. If you want to know counts, you want to look at either the complete table data or group the table data into smaller groups (with the GROUP BY clause). Then you can use aggregate functions to get more information about those groups (or the whole table), like counts, average values, minima, maxima...
Single record information, like an act's ID in your case, is typically not important if you want to use statistic/aggregate methods on grouped data. Suppose your query returns an act name which is used 10 times. Then you have 10 records in your table, each with a unique act_id, but with the same name.
If you need just one act_id that represents each group / act name (and assuming act_id is an autonumbering field), you might include the latest / largest act_id value in the query using the MAX aggregate function:
SELECT NameOfAct, COUNT(*) AS ActCount, MAX(act_id) AS LatestActId
(The rest of the query remains the same.)
Basically, I'm trying to retrieve only 1 record from a table based on catalog_no and packing_list_no. However, the table I'm retrieving the information from has additional details that I don't need but makes the 1 record I need into 3 distinct records.
I tried summing and grouping the info, but I'm still getting 3 records instead of 1.
Any ideas of how to solve this issue?
Your GROUP BY groups your result on the columns quantity picked, quantity shipped and weight shipped. A different value in any of those columns will result into a different row.
You can drop the GROUP BY clause all together, if the desirable result is the packing list and catalog no that you have specified. You can use the GROUP BY clause to columns that you do not use sum to group the result set.
SELECT catalog_no, sum(qty_picked), sum(qty_shipped), sum(weight_shipped), packing_list_no, bay_no, carrier_code, tracking_no FROM oeorder_shipping
WHERE packing_list_no='CP12618525' AND catalog_no='437656500'
GROUP BY bay_no, carrier_code, tracking_no;
I am working on a database with products and lot numbers. Each entry in the Lots table has a Lot Number and a Product description.
Sometimes there are multiple records of the same lot number, for example when an item is repacked a new record is created, but with the same Lot Number and same product description - this is fine. But other times there are problem cases, namely when two different products share the same Lot Number. I am trying to find those.
In other words, there are 3 possibilities:
Lot numbers for which there is only one record in the table.
Lot numbers for which there are multiple records, but the Product description is the same for all of them
Lot numbers for which there are multiple records, and the product descriptions are not all the same.
I need to return only #3, with a separate record for each instance of that Lot Number and product description.
Any help would be greatly appreciated.
Thanks Juan for the sample data. Using this example, I want to return the data contained in Id 2-8, but not 1, 9, 10, 11.
This wasn't easy because lot of time don't use access.
First select unique values using distinct.
Then count how many diferent product appear on each lotnumber using group by
Last join both result and show only the lots with more than one description where total >1
.
SELECT id, Product.lotnumber, Product.Product, total
FROM
Product Inner join
(
SELECT lotnumber, count(*) as total
FROM
(SELECT distinct lotnumber, product
FROM Product)
GROUP BY lotnumber
) SubT On Product.lotnumber = SubT.lotnumber
WHERE total > 1
ORDER BY id
As you can see :
lot 2 have two products (yy and zz)
lot 3 have thre products (aa, bb, cc)
I include my product table:
Sorry for spanish. Field types are Autonumeric, Short Text, and Number
Let's say I have two tables in my database.
TABLE:Categories
ID|CategoryName
01|CategoryA
02|CategoryB
03|CategoryC
and a table that references the Categories and also has a column storing some random number.
TABLE:CategoriesAndNumbers
CategoryType|Number
CategoryA|24
CategoryA|22
CategoryC|105
.....(20,000 records)
CategoryB|3
Now, how do I filter out this data? So, I want to know what the 3 smallest numbers are out of each category and delete the rest. The end result would be like this:
TABLE:CategoriesAndNumbers
CategoryType|Number
CategoryA|2
CategoryA|5
CategoryA|18
CategoryB|3
CategoryB|500
CategoryB|1601
CategoryC|1
CategoryC|4
CategoryC|62
Right now, I can get the smallest numbers between all the categories, but I would like each category to be compared individually.
EDIT: I'm using Access and here's my code so far
SELECT TOP 10 cdt1.sourceCounty, cdt1.destCounty, cdt1.distMiles
FROM countyDistanceTable as cdt1, countyTable
WHERE cdt1.sourceCounty = countyTable.countyID
ORDER BY cdt1.sourceCounty, cdt1.distMiles, cdt1.destCounty
EDIT2: Thanks to Remou, here would be the working query that solved my problem. Thank you!
DELETE
FROM CategoriesAndNumbers a
WHERE a.Number NOT IN (
SELECT Top 3 [Number]
FROM CategoriesAndNumbers b
WHERE b.CategoryType=a.CategoryType
ORDER BY [Number])
You could use something like:
SELECT a.CategoryType, a.Number
FROM CategoriesAndNumbers a
WHERE a.Number IN (
SELECT Top 3 [Number]
FROM CategoriesAndNumbers b
WHERE b.CategoryType=a.CategoryType
ORDER BY [Number])
ORDER BY a.CategoryType
The difficulty with this is that Jet/ACE Top selects duplicate values where they exist, so you will not necessarily get three values, but more, if there are ties. The problem can often be solved with a key field, if one exists :
WHERE a.Number IN (
SELECT Top 3 [Number]
FROM CategoriesAndNumbers b
WHERE b.CategoryType=a.CategoryType
ORDER BY [Number], [KeyField])
However, I do not think it will help in this instance, because the outer table will include ties.
Order it by number and take 3, find out what the biggest number is and then remove rows where Number is greater than the Number.
I imagine it would need to be two seperate queries as your business tier would hold the value for the biggest number out of the 3 results and dynamically build the query to delete the rest.