I'm currently re-working the size filter i built earlier this year for our website. The size filter query works off the stock_id's found in the products query. On occassions, the same product can appear many times, due to it being a single listing as well as appearing inside a mix and match listing.
Because the stock_id remains the same however, whenever i run a query using stock_id In (#products.stock_id#), i only get the one row, when because lets say products.stock_id equals 1234,1234,1235. 1234 will only be shown once rather than twice, how do i get this record to be counted twice? I know it's not the most straightforward of questions but i don't have much time to dedicate to this post unfortunately.
EDIT 1 - Size Filter Query
<cfquery datasource="#application.datasource#" name="size_filter">
Select size_id,
size_description,
size_count
From sizes
Inner Join (
Select stock_sizeid,
Count(*) As size_count
From stock
Where stock_id In (#valueList(products.stock_id)#)
And stock_sizeid Not In ('33','218')
And stock_instock > 0
Group By stock_sizeid
) As stock
On size_id = stock_sizeid
Order By size_description Asc
</cfquery>
Cheat, and JOIN to your id list (instead of using an IN clause):
<cfquery datasource="#application.datasource#" name="size_filter">
Select size_id,
size_description,
size_count
From sizes
Inner Join (Select stock_sizeid,
Count(*) As size_count
From stock
Join (Select stock_id
From (VALUES(#valueList(products.stock_id)#)) a(stock_id)) As ids
On ids.stock_id = stock.stock_id
Where stock_sizeid Not In ('33','218')
And stock_instock > 0
Group By stock_sizeid) As stock
On size_id = stock_sizeid
Order By size_description Asc
</cfquery>
To make VALUES() give rows instead of columns, the correct form is VALUES(1), (2), ...(n). I'm assuming valueList(...) is some client-side procedure that gets run when the statement gets prepared; you'll need to provide an equivalent function to produce this output.
(Note, I've never used coldfusion, so I don't know if this actually works. This type of thing works in most RDBMSs, although some complain)
What this is doing is turning your list into a virtual table, which has all your entries in it, so the JOIN will be assessed multiple times, as normal.
Related
Given a fairly stereotypical scenario with an item table referenced by an images table holding multiple images for the same item, I'm trying to figure out how to retrieve a specific number of items, while collecting all of the image rows.
The setup is trivial, and looks like:
CREATE TABLE items (
id INTEGER PRIMARY KEY,
...
...
)
CREATE TABLE images (
item_id INTEGER PRIMARY KEY,
url STRING,
...
...
)
LIMIT 20 clamps the maximum number of rows in the entire result set, and incidentally truncates mid-way through an item record.
I'm currently doing two queries, but besides being architecturally not at all ideal, it's practically proving quite awkward to coordinate (which makes a lot of sense since I'm definitely doing it wrong). I'm not finding any info on how to coordinate LIMIT with LEFT JOINs, so I thought I'd ask. Thanks!
NB. Similar questions to this do indeed exist, but are asking how to do things like retrieving eg the first (say) 5 images for each item. I'm looking to retrieve (say) 10 items and get all the images for each.
A query like:
SELECT * FROM items ORDER BY ? LIMIT 10
will return 10 rows (at most) from items.
You need to provide the column(s) for the ORDER BY clause if you have some specific sorting condition in mind.
If not then remove the ORDER BY clause, but in this case nothing guarantees the resultset that you will get.
So all you have to do is LEFT join the above query to images:
SELECT it.*, im.*
FROM (SELECT * FROM items ORDER BY ? LIMIT 10) it
LEFT JOIN images im
ON im.item_id = it.id
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.
Overall what I'm trying to achieve is a query that shows the most ordered item from a customer in a database. To achieve this I've tried making a query showing how many times a customer has ordered an item, and now I am trying to create a sub-query in it using TOP1 to discern the most bought items.
With the SQL from the first query (looking weird because I made it with the Access automatic creator):
SELECT
Customers.CustomerFirstName,
Customers.CustomerLastName,
Products.ProductName,
COUNT(SalesQuantity.ProductCode) AS CountOfProductCode
FROM (Employees
INNER JOIN (Customers
INNER JOIN Sales
ON Customers.CustomerCode = Sales.CustomerCode)
ON Employees.EmployeeCode = Sales.EmployeeCode)
INNER JOIN (Products
INNER JOIN SalesQuantity
ON Products.ProductCode = SalesQuantity.ProductCode)
ON Sales.SalesCode = SalesQuantity.SalesCode
GROUP BY
Customers.CustomerFirstName,
Customers.CustomerLastName,
Products.ProductName
ORDER BY
COUNT(SalesQuantity.ProductCode) DESC;
I have tried putting in a subquery after FROM line:
(SELECT TOP1 CountOfProduct(s)
FROM (.....)
ORDER by Count(SalesQuantity.ProductCode) DESC)
I'm just not sure what to put in for the "from"-every other tutorial has the data from an already created table, however this is from a query that is being made at the same time. Just messing around I've put "FROM" and then listed every table, as well as
FROM Count(SalesQuantity.ProductCode)
just because I've seen that in the order by from the other code, and assume that the query is discerning from this count. Both tries have ended with an error in the syntax of the "FROM" line.
I'm new to SQL so sorry if it's blatantly obvious, but any help would be greatly appreciated.
Thanks
As I understand, you want the most purchased product for each customer.
So, begin by building aggregate query that counts product purchases by customer (appears to be done in the posted image). Including customer ID in the query would simplify the next step which is to build another query with TOP N nested query.
Part of what complicates this is unique record identifier is lost because of aggregation. Have to use other fields from the aggregate query to provide unique identifier. Consider:
SELECT * FROM Query1 WHERE CustomerID & ProductName IN
(SELECT TOP 1 CustomerID & ProductName FROM Query1 AS Dupe
WHERE Dupe.CustomerID = Query1.CustomerID
ORDER BY Dupe.CustomerID, Dupe.CountOfProductCode DESC);
Overall what I'm trying to achieve is a query that shows the most ordered item from a customer in a database.
This answers your question. It does not modify your query which is only tangentially related.
SELECT s.CustomerCode, sq.ProductCode, SUM(sq.quantity) as qty
FROM Sales as s INNER JOIN
SalesQuantity as sq
ON s.SalesCode = sq.SalesCode
GROUP BY s.CustomerCode, sq.ProductCode;
To get the most ordered items, you can use this twice:
SELECT s.CustomerCode, sq.ProductCode, SUM(sq.quantity) as qty
FROM Sales as s INNER JOIN
SalesQuantity as sq
ON s.SalesCode = sq.SalesCode
GROUP BY s.CustomerCode, sq.ProductCode
HAVING sq.ProductCode IN (SELECT TOP 1 sq2.ProductCode
FROM Sales as s2 INNER JOIN
SalesQuantity as sq2
ON s2.SalesCode = sq2.SalesCode
WHERE s2.CustomerCode = s.CustomerCode
GROUP BY sq2.ProductCode
);
In almost any other database, this would be simpler, because you would be able to use window functions.
I have a table of existing customers and another table of potential customers. I want to return a list of potential customers rank ordered by the number of radii of existing purchasers that they appear in.
There are many rows in the potential customers table per each existing customer, and the radius around a given existing customer could encompass multiple potential customers. I want to return a list of potential customers ordered by the count of the existing customer radii that they fall within.
SELECT pur.contact_id AS purchaser, count(pot.*) AS nearby_potential_customers
FROM purchasers_geocoded pur, potential_customers_geocoded pot
WHERE ST_DWithin(pur.geom,pot.geom,1000)
GROUP BY purchaser;
Does anyone have advice on how to proceed?
EDIT:
With some help, I wrote this query, which seems to do the job, but I'm verifying now.
WITH prequalified_leads_table AS (
SELECT *
FROM nearby_potential_customers
WHERE market_val > 80000
AND market_val < 120000
)
, proximate_to_existing AS (
SELECT pot.prop_id AS prequalified_leads
FROM purchasers_geocoded pur, prequalified_leads_table pot
WHERE ST_DWithin(pot.geom,pur.geom,100)
)
SELECT prequalified_leads, count(prequalified_leads)
FROM proximate_to_existing
GROUP BY prequalified_leads
ORDER BY count(*) DESC;
I want to return a list of potential customers ordered by the count of the existing customer radii that they fall within.
Your query tried the opposite of your statement, counting potential customers around existing ones.
Inverting that, and after adding some tweaks:
SELECT pot.contact_id AS potential_customer
, rank() OVER (ORDER BY pur.nearby_customers DESC
, pot.contact_id) AS rnk
, pur.nearby_customers
FROM potential_customers_geocoded pot
LEFT JOIN LATERAL (
SELECT count(*) AS nearby_customers
FROM purchasers_geocoded pur
WHERE ST_DWithin(pur.geom, pot.geom, 1000)
) pur ON true
ORDER BY 2;
I suggest a subquery with LEFT JOIN LATERAL ... ON true to get counts. Should make use of the spatial index that you undoubtedly have:
CREATE INDEX ON purchasers_geocoded USING gist (geom);
Thereby retaining rows with 0 nearby customers in the result - your original join style would exclude those. Related:
What is the difference between LATERAL and a subquery in PostgreSQL?
Then ORDER BY the resulting nearby_customers in the outer query (not: nearby_potential_customers).
It's not clear whether you want to add an actual rank. Use the window function rank() if so. I made the rank deterministic while being at it, breaking ties with an additional ORDER BY expression: pot.contact_id. Else, peers are returned in arbitrary order which can change for every execution.
ORDER BY 2 is short syntax for "order by the 2nd out column". See:
Select first row in each GROUP BY group?
Related:
How do I query all rows within a 5-mile radius of my coordinates?
I wrote several SQL queries and executed them against my table. Each individual query worked. I kept adding functionality until I got a really ugly working query. The problem is that I have to manually change a value every time I want to use it. Can you assist in making this query automatic rather than “manual”?
I am working with DB2.
Table below shows customers (cid) from 1 to 3. 'club' is a book seller, and 'qnty' is the number of books the customer bought from each 'club'. The full table has 45 customers.
Image below shows all the table elements for the first 3 users (cid=1 OR cid=2 OR cid=3). The final purpose of all my queries (once combined) is it to find the single 'club' with the largest 'qnty' for each 'cid'. So for 'cid =1' the 'club' is Readers Digest with 'qnty' of 3. For 'cid=2' the 'club' is YRB Gold with 'qnty' of 5. On and on until cid 45 is reached.
To give you a background on what I did here are my queries:
(Query 1-starting point for cid=1)
SELECT * FROM yrb_purchase WHERE cid=1
(Query 2 - find the 'club' with the highest 'qnty' for cid=1)
SELECT *
FROM
(SELECT club,
sum(qnty) AS t_qnty
FROM yrb_purchase
WHERE cid=1
GROUP BY club)results
ORDER BY t_qnty DESC
(Query 3 – combine the record from the above query with it’s cid)
SELECT cid,
temp.club,
temp.t_qnty
FROM yrb_purchase AS p,
(SELECT *
FROM
(SELECT club,
sum(qnty) AS t_qnty
FROM yrb_purchase
WHERE cid=1
GROUP BY club)results
ORDER BY t_qnty DESC FETCH FIRST 1 ROWS ONLY) AS TEMP
WHERE p.cid=1
AND p.club=temp.club
(Query 4) make sure there is only one record for cid=1
SELECT cid,
temp.club,
temp.t_qnty
FROM yrb_purchase AS p,
(SELECT *
FROM
(SELECT club,
sum(qnty) AS t_qnty
FROM yrb_purchase
WHERE cid=1
GROUP BY club)results
ORDER BY t_qnty DESC FETCH FIRST 1 ROWS ONLY) AS TEMP
WHERE p.cid=1
AND p.club=temp.club FETCH FIRST ROWS ONLY
To get the 'club' with the highest 'qnty' for customer 2, I would simply change the text cid=1 to cid=2 in the last query above. My query seems to always produce the correct results. My question is, how do I modify my query to get the results for all 'cid's from 1 to 45 in a single table? How do I get a table with all the cid values along with the club which sold that cid the most books, and how many books were sold within one tablei? Please keep in mind I am hoping you can modify my query as opposed to you providing a better query.
If you decide that my query is way too ugly (I agree with you) and choose to provide another query, please be aware that I just started learning SQL and may not be able to understand your query. You should be aware that I already asked this question: For common elements, how to find the value based on two columns? SQL but I was not able to make the answer work (due to my SQL limitations - not because the answer wasn't good); and in the absence of a working answer I could not reverse engineer it to understand how it works.
Thanks in advance
****************************EDIT #1*******************************************
The results of the answer is:
You could use OLAP/Window Functions to achieve this:
SELECT
cid,
club,
qnty
FROM
(
SELECT
cid,
club,
qnty,
ROW_NUMBER() OVER (PARTITION BY cid order by qnty desc) as cid_club_rank
FROM
(
SELECT
cid,
club,
sum(qnty) as qnty
FROM yrb_purchase
GROUP BY cid, club
) as sub1
) as sub2
WHERE cid_club_rank = 1
The inner most statement (sub1) just grabs a total quantity for each cid/club combination. The second inner most statement (sub2) creates a row_number for each cid/club combination ordering by the quantity (top down). Then the outer most query chooses only records where that row_number() is 1.