T SQL select last sale of each customer - sql

I'm trying to retrieve the last sale date for each customer as follows but it is just returning the last entry in the table:
Select top 1 InvoiceDate
,Customer
from salestable a
order by InvoiceDate desc
Help will be greatly appreciated.

Don't use TOP 1 - that's why you're returning only 1 result.
Try using MAX and GroupBy Customer
SELECT Customer, MAX(InvoiceDate)
FROM SalesTable
GROUP By Customer
ORDER By MAX(InvoiceDate) DESC

Related

SQL QUERY - Filter date from the beginning

How to write SQL query that will sum the amount from the previous days/years. Like from the start.
Scenario I want to compute accumulated sales of the store from the day it was opened.
Example
SELECT SUM(AMOUNT)
FROM TransactionTable
WHERE TransactionDate = ???
The plan that I have is to query on this table and get the oldest transaction date record, then I will use that in the WHERE condition. Do you think that it is the best solution?
You can try below using having min(transaction) which will give you the date when transaction first started
select sum (amt) from
(
SELECT SUM(AMOUNT) as amt from TransactionTable
group by TransactionDate
having TransactionDate between min(TransactionDate) and getdate()
)A
To compute accumulated sales of the store from the day it started you can use SUM with OVER clause
SELECT TransactionDate, SUM(AMOUNT) OVER (ORDER BY TransactionDate) AS AccumulatedSales
FROM TransactionTable
use group by TransactionDate
SELECT convert(date,TransactionDate), SUM(AMOUNT) from TransactionTable
group by convert(date,TransactionDate)

Query on MAX on date column, and COUNT of another column

I performed the following query with cte's, but I was wondering if there was a simpler way of writing the code, maybe with subqueries? I'm retrieving everything from one table SALES, but I'm using 3 columns: AgentID, SaleDate, and OrderID.
WITH RECENT_SALE AS(
SELECT AGENTID,(
SALEDATE,
ROW_NUMBER() OVER (PARTITION BY AGENTID ORDER BY SALEDATE DESC) AS RN
FROM SALES
)
,
COUNT_SALE AS (
SELECT AGENTID,
COUNT(ORDERID) AS COUNTORDERS
FROM SALES
)
SELECT RECENT_SALE.MRN,
SALEDATE,
COUNTORDERS
FROM RECENT_SALE
INNER JOIN COUNT_SALE ON RECENT_SALE.AGENTID = COUNT_SALE.AGENTID;
It looks to me like you're just trying to get the total number of sales per agent as well as the date of his or her most recent sale? If I understand your structure correctly (and I may not), then it seems pretty straightforward. I'm guessing orderid is the primary key of SALES?
SELECT agentid, MAX(saledate) AS saledate -- Most recent sale date
, COUNT(orderid) AS countsales -- total sales
FROM sales
GROUP BY agentid;
There does not seem to be any need for CTEs or subqueries here.
Try this:
SELECT
saledate,
AGENTID,
count(orderid) over(partition by AGENTID order by saledate)
FROM SALES
group by
saledate,
AGENTID

Teradata - Group the amount by product with the latest date of purchase in Teradata

I am new to Teradata, can anyone help me with below query.
I've a custom table with millions of records like given below :
Basically, I need to group the amount by product with the latest date of purchase. The Columns I need is Cust_id, Cust_name, date, Product and amount.
Need the result set as below:
Please help me with this.
Thanks in advance!
You can use aggregation along with qualify and rank to get your desired result.
select Custid, custname, Date1, product, sum(amount) as amount
from table1
group by custid, custname, product, date1
qualify rank() over(partition by custid, custname order by date1 desc) = 1
order by custname asc, date1 desc;
Result:
P.S. It's not clear why records with id 601 are missing from your sample desired output

Sql Subquery Syntax

I want to execute a subquery using the current customer ID as I try to describe below
SELECT DISTINCT Customer_Id,
(SELECT SUM (total) FROM Orders where Customer_Id = Customer_Id AND CAST(Date) > DayIspecify )
FROM Orders where shop_id= '1-9THT'
What I want is to calculate the SUM each customer spent over a specified time period on the specific shop.
SELECT Customer_Id, SUM(total) SumTotal
FROM Orders
where shop_id= '1-9THT'
group by Customer_id
Not require subquery
Try this:
SELECT Customer_Id,SUM(total)FROM Orders WHERE shop_id='1-9THT' GROUP BY Customer_Id
(Updated) Try:
select Customer_Id,
sum(case when o.shop_id = '1-9THT' and Date > DayIspecify
then total else 0 end) total
from Orders
group by Customer_Id
- to return all customers recorded on the Orders table, together with the values of any of their orders placed through shop 1-9THT after the date specified. (Change > to >= to make it on or after the date specified.)
Use SQL GroupBy
SELECT DISTINCT Customer_Id, SUM (total) FROM Orders where shop_id= '1-9THT' group by customer_Id

Can I limit the amount of rows to be used for a group in a GROUP BY statement

I'm having an odd problem
I have a table with the columns product_id, sales and day
Not all products have sales every day. I'd like to get the average number of sales that each product had in the last 10 days where it had sales
Usually I'd get the average like this
SELECT product_id, AVG(sales)
FROM table
GROUP BY product_id
Is there a way to limit the amount of rows to be taken into consideration for each product?
I'm afraid it's not possible but I wanted to check if someone has an idea
Update to clarify:
Product may be sold on days 1,3,5,10,15,17,20.
Since I don't want to get an the average of all days but only the average of the days where the product did actually get sold doing something like
SELECT product_id, AVG(sales)
FROM table
WHERE day > '01/01/2009'
GROUP BY product_id
won't work
If you want the last 10 calendar day since products had a sale:
SELECT product_id, AVG(sales)
FROM table t
JOIN (
SELECT product_id, MAX(sales_date) as max_sales_date
FROM table
GROUP BY product_id
) t_max ON t.product_id = t_max.product_id
AND DATEDIFF(day, t.sales_date, t_max.max_sales_date) < 10
GROUP BY product_id;
The date difference is SQL server specific, you'd have to replace it with your server syntax for date difference functions.
To get the last 10 days when the product had any sale:
SELECT product_id, AVG(sales)
FROM (
SELECT product_id, sales, DENSE_RANK() OVER
(PARTITION BY product_id ORDER BY sales_date DESC) AS rn
FROM Table
) As t_rn
WHERE rn <= 10
GROUP BY product_id;
This asumes sales_date is a date, not a datetime. You'd have to extract the date part if the field is datetime.
And finaly a windowing function free version:
SELECT product_id, AVG(sales)
FROM Table t
WHERE sales_date IN (
SELECT TOP(10) sales_date
FROM Table s
WHERE t.product_id = s.product_id
ORDER BY sales_date DESC)
GROUP BY product_id;
Again, sales_date is asumed to be date, not datetime. Use other limiting syntax if TOP is not suported by your server.
Give this a whirl. The sub-query selects the last ten days of a product where there was a sale, the outer query does the aggregation.
SELECT t1.product_id, SUM(t1.sales) / COUNT(t1.*)
FROM table t1
INNER JOIN (
SELECT TOP 10 day, Product_ID
FROM table t2
WHERE (t2.product_ID=t1.Product_ID)
ORDER BY DAY DESC
)
ON (t2.day=t1.day)
GROUP BY t1.product_id
BTW: This approach uses a correlated subquery, which may not be very performant, but it should work in theory.
I'm not sure if I get it right but If you'd like to get the average of sales for last 10 days for you products you can do as follows :
SELECT Product_Id,Sum(Sales)/Count(*) FROM (SELECT ProductId,Sales FROM Table WHERE SaleDAte>=#Date) table GROUP BY Product_id HAVING Count(*)>0
OR You can use AVG Aggregate function which is easier :
SELECT Product_Id,AVG(Sales) FROM (SELECT ProductId,Sales FROM Table WHERE SaleDAte>=#Date) table GROUP BY Product_id
Updated
Now I got what you meant ,As far as I know it is not possible to do this in one query.It could be possible if we could do something like this(Northwind database):
select a.CustomerId,count(a.OrderId)
from Orders a INNER JOIN(SELECT CustomerId,OrderDate FROM Orders Order By OrderDate) AS b ON a.CustomerId=b.CustomerId GROUP BY a.CustomerId Having count(a.OrderId)<10
but you can't use order by in subqueries unless you use TOP which is not suitable for this case.But maybe you can do it as follows:
SELECT PorductId,Sales INTO #temp FROM table Order By Day
select a.ProductId,Sum(a.Sales) /Count(a.Sales)
from table a INNER JOIN #temp AS b ON a.ProductId=b.ProductId GROUP BY a.ProductId Having count(a.Sales)<=10
If this is a table of sales transactions, then there should not be any rows in there for days on which there were no Sales. I.e., If ProductId 21 had no sales on 1 June, then this table should not have any rows with productId = 21 and day = '1 June'... Therefore you should not have to filter anything out - there should not be anything to filter out
Select ProductId, Avg(Sales) AvgSales
From Table
Group By ProductId
should work fine. So if it's not, then you have not explained the problem completely or accurately.
Also, in yr question, you show Avg(Sales) in the example SQL query but then in the text you mention "average number of sales that each product ... " Do you want the average sales amount, or the average count of sales transactions? And do you want this average by Product alone (i.e., one output value reported for each product) or do you want the average per product per day ?
If you want the average per product alone, for just thpse sales in the ten days prior to now? or the ten days prior to the date of the last sale for each product?
If the latter then
Select ProductId, Avg(Sales) AvgSales
From Table T
Where day > (Select Max(Day) - 10
From Table
Where ProductId = T.ProductID)
Group By ProductId
If you want the average per product alone, for just those sales in the ten days with sales prior to the date of the last sale for each product, then
Select ProductId, Avg(Sales) AvgSales
From Table T
Where (Select Count(Distinct day) From Table
Where ProductId = T.ProductID
And Day > T.Day) <= 10
Group By ProductId