I need to generate a report of customers with the account status of COLLECTIONS and has more than 1 consecutive DECLINED charged.
Customer Table
=====================
CustomerID
FirstName
LastName
Email
Status (Collections)
Charge
=====================
ChargeID
CustomerID
DateCharged
Amount
ACK (Declined)
SELECT Customer.CustomerID, Customer.FirstName, Customer.LastName,
Customer.Status, Charge.ChargeID, Charge.Amount, Charge.DateCharged, Charge.ACK
FROM Customers
INNER JOIN Charge
ON Customer.CustomerID=Charge.CustomerID
AND Charge.ACK = 'Declined'
A customer has to have at least 2 DECLINED charges before they are sent to collections. How can I check to see if a customer has 2 declines?
Normally, I would say just do an aggregation with a having clause.
However, your query suggests that you also want the details on the declines. Instead, using a window function to calculate the total number of declines:
SELECT *
FROM (SELECT c.CustomerID, c.FirstName, c.LastName,
c.Status, ch.ChargeID, ch.Amount, ch.DateCharged, ch.ACK,
sum(case when ch.ACK = 'Declined' then 1 else 0 end) over
(partition by c.customerId) as NumDeclines
FROM Customers c INNER JOIN
Charge ch
ON c.CustomerID = ch.CustomerID
) cc
WHERE ACK = 'Declined' and NumDeclines >= 2
ORDER BY CustomerId, DateCharged;
If you just want the customers and not the detail, then do:
SELECT c.CustomerID, c.FirstName, c.LastName, c.Status
FROM Customers c INNER JOIN
Charge ch
ON c.CustomerID = ch.CustomerID
WHERE ACK = 'Declined'
GROUP BY c.CustomerID, c.FirstName, c.LastName, c.Statu
HAVING count(*) >= 2;
Per my comment, this is how I would accomplish the task at hand.
SELECT
*
FROM (
SELECT
Row_Number() OVER (PARTITION BY Customer.CustomerID ORDER BY Charge.DateCharged DESC) AS [Row],
Customer.CustomerID, Customer.FirstName, Customer.LastName,
Customer.Status, Charge.ChargeID, Charge.Amount, Charge.DateCharged, Charge.ACK
FROM Customers
INNER JOIN Charge ON Customer.CustomerID=Charge.CustomerID
) a
INNER JOIN (
SELECT
Row_Number() OVER (PARTITION BY Customer.CustomerID ORDER BY Charge.DateCharged DESC) AS [Row],
Customer.CustomerID, Customer.FirstName, Customer.LastName,
Customer.Status, Charge.ChargeID, Charge.Amount, Charge.DateCharged, Charge.ACK
FROM Customers
INNER JOIN Charge ON Customer.CustomerID=Charge.CustomerID
) b ON a.CustomerID=b.CustomerID
WHERE a.[Row]=b.[Row]-1
AND a.ACK = 'Declined'
AND b.ACK = 'Declined'
AND a.[Row] IN (1,2)
AND b.[Row] IN (1,2)
Related
I have 2 tables:
CUSTOMERS (ID, FIRSTNAME, LASTNAME, ADDRESS);
ORDERS (ID, PRODUCT_NAME, PRODUCT_PRICE, DATE_ORDER DATE, ID_CUSTOMER, AMOUNT);
Get the first and last names of the customers who bought the biggest amount of a product in one order.
The orders without customer should not be considered. Please sort by FIRSTNAME and LASTNAME
SELECT firstname, lastname
FROM customers
LEFT JOIN orders ON customers.id = orders.id_customer
GROUP BY customers.firstname
HAVING (SELECT MAX(orders.amount) FROM orders);
What I'm doing wrong? thx
If you want one customer with the largest value of amount, then simplest method is order by and then fetching only one row:
select c.firstname, c.lastname
from customers c join
orders o
on c.id = o.id_customer
order by o.amount desc
fetch first 1 row only;
If you want the biggest amount per product, then window functions are the right approach
select pc.*
from (select o.product, c.firstname, c.lastname, o.amount,
rank() over (partition by o.product order by o.amount desc) as seqnum
from customers c join
orders o
on c.id = o.id_customer
) pc
where seqnum = 1;
I'm asked to find the top user for different countries, however, one of the countries has 2 users with the same amount spent so they should both be the top users, but I can't get the max value for 2 values in this country.
Here is the code:
WITH t1 AS (
SELECT c.customerid,SUM(i.total) tot
FROM invoice i
JOIN customer c ON c.customerid = i.customerid
GROUP BY 1
ORDER BY 2 DESC
),
t2 AS (
SELECT c.customerid as CustomerId ,c.firstname as FirstName,c.lastname as LastName, i.billingcountry as Country,MAX(t1.tot) as TotalSpent
FROM t1
JOIN customer c
ON c.customerid = t1.customerid
JOIN invoice i ON i.customerid = c.customerid
GROUP BY 4
ORDER BY 4
)
SELECT *
FROM t2
BILLINGCOUNTRY is in Invoice, and it has the name of all the countries.
TOTAL is also in invoice and it shows how much is spent for each purchase by Customer (so there are different fees and taxes for each purchase and total shows the final price payed by the user at each time)
Customer has id,name,last name and from its' ID I'm extracting the total of each of his purchases
MAX was used after finding the sum for each Customer and it was GROUPED BY country so that i could find the max for each country, however I can't seem to find the max of the last country that had 2 max values
Use rank() or dense_rank():
SELECT c.*, i.tot
FROM (SELECT i.customerid, i.billingCountry, SUM(i.total) as tot,
RANK() OVER (PARTITION BY i.billingCountry ORDER BY SUM(i.total) DESC) as seqnum
FROM invoice i
GROUP BY 1, 2
) i JOIN
customer c
ON c.customerid = i.customerid
WHERE seqnum = 1;
The subquery finds the amount per customer in each country -- and importantly calculates a ranking for the combination with ties having the same rank. The outer query just brings in the additional customer information that you seem to want.
here is how it worked for me since i was restricted from using many Commands such RIGHT JOIN and RANK() (As what Gordon Linoff suggessted) so i had to create a 3rd case for the anamoly and join it using union. this solution works only on this case, the good solution is the one posted by Gordon Linoff:
WITH t1 AS (
SELECT c.customerid,SUM(i.total) tot
FROM invoice i
JOIN customer c ON c.customerid = i.customerid
GROUP BY 1
ORDER BY 2 DESC
),
t2 AS (
SELECT c.customerid as CustomerId ,c.firstname as FirstName,c.lastname as LastName, i.billingcountry as Country,MAX(t1.tot) as TotalSpent
FROM t1
JOIN customer c
ON c.customerid = t1.customerid
JOIN invoice i ON i.customerid = c.customerid
GROUP BY 4
ORDER BY 4
) ,
t3 AS (
SELECT DISTINCT c.customerid as CustomerId ,c.firstname as FirstName,c.lastname as LastName, i.billingcountry as Country,t1.tot as TotalSpent
FROM t1
JOIN customer c
ON c.customerid = t1.customerid
JOIN invoice i ON i.customerid = c.customerid
WHERE i.billingcountry = 'United Kingdom'
ORDER BY t1.tot DESC
LIMIT 2
)
SELECT *
FROM t2
UNION
SELECT * FROM t3
ORDER BY t2.country
I have this DB and I need help with this query
Find the customer ID, first name, last name and the movie Name
of the customer that bought the most ticket in that day
I found the customer who bought the highest number of tickets in that day, now I need to find the movies that he bought tickets for
SELECT c.*, COUNT(*) 'bought'
FROM customer c JOIN ticket t ON c.customerId=t.customerId
GROUP BY c.customerId
HAVING bought=(SELECT MAX(T1.CNT)
FROM (SELECT COUNT(*) AS CNT
FROM customer c JOIN ticket t ON c.customerId=t.customerId
GROUP BY c.customerId) AS T1)
So without building the database and populating it with dummy data I can't test this, but I think I found a solution for you.
SELECT C.CUSTOMERID, C.FIRSTNAME, C.LASTNAME, M.TITLE
FROM CUSTOMER C JOIN TICKET T ON C.CUSTOMERID = T.CUSTOMERID JOIN SHOWS S ON T.SHOWNUMBER = S.SHOWNUMBER JOIN MOVIE M ON M.MOVIEID = S.MOVIEID
WHERE C.CUSTOMERID IN(
SELECT C1.CUSTOMERID FROM(
SELECT CUST.CUSTOMERID, COUNT(*) 'BOUGHT'
FROM CUSTOMER CUST JOIN TICKET TICK ON CUST.CUSTOMERID = TICK.CUSTOMERID
GROUP BY CUST.CUSTOMERID
HAVING BOUGHT = (SELECT MAX(T1.CNT) FROM (SELECT COUNT(*) AS CNT FROM CUSTOMER CUSTO JOIN TICKET TICKE ON CUSTO.CUSTOMERID = TICKE.CUSTOMERID GROUP BY CUSTO.CUSTOMERID)AS T1) AS C1);
For example I have to write a query that shows the customer who had spent the most in each country but if a country has two customers with same max value i have to show them both in the output.
I have wrote the query that return the maximum value for each customer in each country but the last country in my example which is 'United Kingdom' has two customers with same maximum values and i couldn't show them both.
SELECT c1.CustomerId, c1.FirstName,c1.LastName,c1.Country,
MAX(c1.TotalSpent) as TotalSpent
FROM
(SELECT c.CustomerId,c.FirstName, c.LastName,i.BillingCountry
Country, SUM(i.Total) totalspent
FROM Customer c
JOIN Invoice i
ON c.CustomerId = i.CustomerId
GROUP BY 1
ORDER BY totalspent
) c1
GROUP BY 4
ORDER BY Country
Use window functions!:
SELECT c.*
FROM (SELECT c.CustomerId, c.FirstName, c.LastName, i.BillingCountry as Country,
SUM(i.Total) as totalspent,
DENSE_RANK() OVER (PARTITION BY i.BillingCountry ORDER BY SUM(i.Total) DESC) as seqnum
FROM Customer c JOIN
Invoice i
ON c.CustomerId = i.CustomerId
GROUP BY c.CustomerId, c.FirstName, c.LastName, i.BillingCountry
) c
WHERE seqnum = 1
ORDER BY Country;
This also fixes your GROUP BY clauses so they are consistent with the columns being selected.
I have 2 tables, Customer and CustomerActivity as showed in the picture below:
I want to output a table that:
has all columns from Customer table where CustomerType = 'Existing Customer', plus 2 more columns:
totalActivity (count activityID) - shows total activity number of each customer.
latestActivity (max checkinTime) - shows the most recent activity datetime
So far I have these 2 queries but I don't know how to combine/join and filter them to get what I need. Anyone can help with 1 query (and some explanation would be perfect)
SELECT customerId, firstName, birthDate, customerType
FROM Customer
WHERE Customer.customerType = 'Existing Customer'
SELECT t1.activityId, t1.checkinTime, t1.customerId
FROM CustomerActivity t1
inner join (
SELECT customerId, max(checkinTime) as Lastest
FROM CustomerActivity
group by customerId
) t2 on t1.customerId = t2.customerId and t1.checkinTime = t2.Lastest
You're actually close. Here is what your query should look like:
SELECT
c.customerId,
c.firstName,
c.lastName,
c.birthDate,
c.customerType,
ca.totalActivity,
ca.latestActivity
FROM Customer c
INNER JOIN(
SELECT
customerId,
latestActivity = MAX(checkinTime),
totalActivity = COUNT(*)
FROM CustomerActivity
GROUP BY customerId
) ca
ON ca.customerId = c.customerId
WHERE
c.customerType = 'Existing Customer'
The subquery (inside the INNER JOIN) retrieves the total number of activities by using COUNT(*) and latest activity using MAX(checkinTime) of each customer. After that, you would want to join it to the Customer table on customerId. You then add a WHERE clause to filter for 'Existing Customer' only.
I haven't tested it against an actual schema, but something like this should work (this approach will show customers even if they have no activity, simply change the left join to an inner join if you only want customers with activity):
SELECT c.CustomerID
, c.FirstName
, c.BirthDate
, c.CustomerType
, COUNT(ca.ActivityID) AS TotalActivity
, MAX(ca.CheckinTime) AS MostRecentActivity
FROM Customer c
LEFT JOIN CustomerActivity ca ON c.CustomerID = ca.CustomerID
WHERE c.CustomerType = 'Existing Customer'
GROUP BY c.CustomerID
, c.FirstName
, c.BirthDate
, c.CustomerType
You can get what you want without group by, by using row_number() and window fu instead:
SELECT c.*, ca.numActivities, ca.activityId as LastActivity
FROM Customer c JOIN
(select ca.*,
count(*) over (partition by ca.CustomerId) as numActivities
row_number() over (partition by ca.CustomerId order by checkinTime desc) as seqnum
from CustomerActivity ca
) ca
on c.customerId = ca.customerId and ca.seqnum = 1
WHERE c.customerType = 'Existing Customer';
This version will let you get whatever columns you like from the most recent activity row.
EDIT:
In your original question, I thought you wanted the latest activity. If you just want the latest datetime, then aggregation works:
SELECT c.*, ca.numActivities, ca.lastActivityDateTime
FROM Customer c JOIN
(select ca.*,
count(*) as numActivities
max(checkinTime) as lastActivityDateTime
from CustomerActivity ca
) ca
on c.customerId = ca.customerId
WHERE c.customerType = 'Existing Customer';
Select c.customerId, c.firstName, c.lastName, c.birthDate, c.customerType, gca.latestCheckIn, gca.count
from customer as c,
(select ca.customerId, max(ca.checkInTime) as latestCheckIn, count(*) as checkinCount
from customerActivity as ca
group by ca.customerId) as gca
where gca.customerId = c.customerId AND c.customerType = 'Existing Customer'
If you clarify more about customer with no activity, one can change the query to using left join