I have one table looking like
Customer:
| CUSTOMER_ID | CUSTOMER_NAME | BANK_ID |
-----------------------------------------
| 1 | a | b |
| 2 | b1 | c |
| 3 | b1 | d |
| 4 | C | e |
| 5 | a | f |
| 6 | b1 | g |
I have a query that looks for all customer names that are not unique and group them together. It also assigns a row number to the rows in each group.
The output of this query is:
RowNumber|customer_id | customer_name |
1 | 1 | a |
2 | 5 | a |
1 | 2 | b1 |
2 | 3 | b1 |
3 | 6 | b1 |
I want to iterate on all the groups. For each group I want to join the members of the group with rows in a different table.Is there any way to operate on each sub group and apply business logic on the items in each sub group ?
for example: let's assume that for each group I want to leave the first customer if all the customers in this group live in the same place and work at the same place.
I have the following table:
|customer id | address | workplace-name |
|1 | street1 | work1|
|2 | street2 | work1|
|3 | street1 | work2|
|4 | street5 | work7|
|5 | street1 | work1|
|6 | street2 | work1|
You can notice that only the customers in the first group live and work at the same place (customers id: 1,5). If you look at the second group (customers id:2,3,6) - they don't all live and work at the same place.
The result of this query will be: customer id 5 as it's in the same group with customer id 5 and they both live and work in the same place. But customer 5 is the second in this group.
What's the easiest way to do it ?
Try this:
WITH A(Customer_id, Customer_name)
AS(SELECT Customer_id, Customer_name
FROM Customer
WHERE Customer_name IN
(SELECT Customer_name FROM Customer
GROUP BY Customer_name
HAVING COUNT(Customer_name) >1)
)
SELECT RANK() OVER (ORDER BY Customer_id ASC) AS RowNumber
, Customer_id, Customer_Name
FROM A
ORDER BY Customer_name, Customer_id;
Or you can also use JOIN for that
WITH A(Customer_id, Customer_name)
AS (SELECT c.Customer_id, c.Customer_name
FROM Customer c
JOIN
(SELECT Customer_id FROM Customer
WHERE Customer_name IN ( SELECT Customer_name FROM Customer
GROUP BY Customer_name
HAVING COUNT(Customer_name) >1)
) AS c1
ON c.Customer_id = C1.customer_id)
SELECT RANK() OVER (ORDER BY A.customer_id ASC) AS RowNumber
, Customer_id, Customer_Name
FROM A
ORDER BY Customer_name, Customer_id;
See this SQLFiddle
I couldn't find any way to do it in a single query. I've created a cursor that does what I want to do: Iterate on all the rows of one table, apply business logic and insert relevant rows to the output table.
Related
This question already has answers here:
Join to only the "latest" record with t-sql
(7 answers)
Fetch the rows which have the Max value for a column for each distinct value of another column
(35 answers)
Closed 4 months ago.
I want to list all customer with the latest phone number and most recent customer type
the phone number and type of customers are changing periodically so I want the latest record only without getting old values based on the lastestupdate column
Customer:
+------------+--------------------+------------+
|latestUpdate| CustID | AddID | TypeID |
+------------+--------+-----------+-------------
| 2020-03-01 | 1 | 1 | 1 |
| 2020-04-07 | 2 | 2 | 2 |
| 2020-06-13 | 3 | 3 | 3 |
| 2020-03-29 | 4 | 4 | 4 |
| 2020-02-06 | 5 | 5 | 5 |
+------------+--------+------------+----------+
CustomerAddress:
+------------+--------+-----------+
|latestUpdate| AddID | Mobile |
+------------+--------+-----------+
| 2020-03-01 | 1 | 66666 |
| 2020-04-07 | 1 | 55555 |
| 2020-06-13 | 2 | 99999 |
| 2020-03-29 | 3 | 11111 |
| 2020-02-06 | 3 | 22222 |
+------------+--------+-----------+
CustomerType:
+------------+--------+-----------+
|latestUpdate| TypeId | TypeName |
+------------+--------+-----------+
| 2020-03-01 | 1 | First |
| 2020-04-07 | 1 | Second |
| 2020-06-13 | 3 | Third |
| 2020-03-29 | 4 | Fourth |
| 2020-02-06 | 5 | Fifth |
+------------+--------+-----------+
When I tried to join I am always getting duplicated customerID not only the latest record
I want to Display Customer.CustID and CustomerType.TypeName and CustomerAddress.Mobile
You need to make sub-queries for most recent customer type and latest phone number like this:
SELECT *
FROM (
SELECT latestUpdate, CustID, AddID, TypeID,
ROW_NUMBER() OVER (PARTITION BY CustID ORDER BY latestUpdate DESC) AS RowNumber
FROM Customer
) AS c
INNER JOIN (
SELECT latestUpdate, AddID, Mobile,
ROW_NUMBER() OVER (PARTITION BY AddId ORDER BU ltestUpdate DESC) AS RowNumber
FROM CustomerAddress
) AS t
ON c.AddId = t.AddId
INNER JOIN CustomerType ct
ON ct.TypeId = c.TypeId
WHERE c.RowNumber = 1
AND t.RowNumber = 1
A simpler way than using row_number would be using cross apply together with top 1 in an ordered subquery:
select c.CustId, p.Mobile
from Customer c
cross apply (
select top 1 Mobile
from CustomerAddress a
where c.CustId = a.AddId
order by a.latestUpdate
) p
You need to use some subqueries :
SELECT *
FROM Customer AS C
LETF OUTER JOIN (SELECT *, ROW_NUMBER() OVER(PARTITION BY CustID ORDER BY LastestUpdate DESC) AS N
FROM CustomerAddress) AS A
ON C.CustID = A.CustID AND N = 1
LETF OUTER JOIN (SELECT *, ROW_NUMBER() OVER(PARTITION BY CustID ORDER BY LastestUpdate DESC) AS N
FROM CustomerType) AS T
ON C.CustID = T.CustID AND N = 1
If you have had used Temporal table which is an ISO SQL Standard feature for data history of table, you will always have the lastest rows inside the main table, old rows stays into history table and can be queried with a time point or date interval restriction.
This is it:
select * from (select *,RANK() OVER (
PARTITION BY b.AddID
ORDER BY b.latestUpdate DESC,
) as rank1
from
Customer a
left join
CustomerAddress b
on
a.AddID=b.AddID
left join
CustomerType c
on
v.TypeId =c.TypeId
) where rank1=1;
You should join the tables using the "APPLY" operator.
See: Link
I want to left join a table with the latest record only.
I have Customer1 table:
+--------+----------+
| CustID | CustName |
+--------+----------+
| 1 | ABC123 |
| 2 | 456XYZ |
| 3 | 5PQR3 |
| 4 | 789XYZ |
| 5 | 789A |
+--------+----------+
SalesInvoice table:
+------------+--------+-----------+
| InvDate | CustID | InvNumber |
+------------+--------+-----------+
| 2020-03-01 | 1 | IV236 |
| 2020-04-07 | 1 | IV644 |
| 2020-06-13 | 2 | IV869 |
| 2020-03-29 | 3 | IV436 |
| 2020-02-06 | 3 | IV126 |
+------------+--------+-----------+
And I want this required output:
+--------+------------+-----------+
| CustID | InvDate | InvNumber |
+--------+------------+-----------+
| 1 | 2020-04-07 | IV644 |
| 2 | 2020-06-13 | IV869 |
| 3 | 2020-03-29 | IV436 |
| 4 | | |
| 5 | | |
+--------+------------+-----------+
For quick and easy, below is the sample code.
drop table if exists #Customer1
create table #Customer1(CustID int, CustName varchar (100))
insert into #Customer1 values
(1,'ABC123'),
(2,'456XYZ'),
(3,'5PQR3'),
(4,'789XYZ'),
(5,'789A')
drop table if exists #SalesInvoice
create table #SalesInvoice(InvDate DATE, CustID INT, InvNumber varchar (100))
insert into #SalesInvoice values
('2020-03-01',1,'IV236'),
('2020-04-07',1,'IV644'),
('2020-06-13',2,'IV869'),
('2020-03-29',3,'IV436'),
('2020-02-06',3,'IV126')
I like using TOP 1 WITH TIES in this case:
SELECT TOP 1 WITH TIES c.CustID, i.InvDate, i.InvNumber
FROM #Customer1 c
LEFT JOIN #Invoices i ON c.CustID = i.CustID
ORDER BY ROW_NUMBER() OVER (PARTITION BY c.CustID ORDER BY i.InvDate DESC);
Demo
The top 1 trick here is to order by row number, assigning a sequence to each customer, with the sequence descending by invoice date. Then, this approach retains just the most recent invoice record for each customer.
I recommend outer apply:
select c.*, i.*
from #c c outer apply
(select top (1) i.*
from #invoices i
where i.custId = c.custId
order by i.invDate desc
) i;
outer apply implements a special type of join called a "lateral join". This is a very powerful construct. But when learning about them, you can think of a lateral join as a correlated subquery that can return more than one column and more than one row.
You can try ROW_NUMBER window function instead of lateral joins with this simple self-explaining T-SQL
SELECT c.CustID
, d.InvDate
, d.InvNumber
FROM #C c
LEFT JOIN (
SELECT *
, ROW_NUMBER() OVER (PARTITION BY CustID ORDER BY InvDate DESC) AS RowNo
FROM #D
) d
ON c.CustID = d.CustID
AND d.RowNo = 1
Basically ROW_NUMBER is used to filter the "last" invoice in one table scan, instead of performing SELECT TOP 1 ... ORDER BY in the correlated query which has to be executed multiple times -- as much as the number of customers.
I'm trying to find a performant and easy-to-read query to get a distinct value from one column, if all rows in the table matches a certain criteria.
I have a table that tracks e-commerce orders and whether they're delivered on time, contents and schema as following:
> select * from orders;
+----+--------------------+-------------+
| id | delivered_on_time | customer_id |
+----+--------------------+-------------+
| 1 | 1 | 9 |
| 2 | 0 | 9 |
| 3 | 1 | 10 |
| 4 | 1 | 10 |
| 5 | 0 | 11 |
+----+--------------------+-------------+
I would like to get all distinct customer_id's which have had all their orders delivered on time. I.e. I would like an output like this:
+-------------+
| customer_id |
+-------------+
| 10 |
+-------------+
What's the best way to do this?
I've found a solution, but it's a bit hard to read and I doubt it's the most efficient way to do it (using double CTE's):
> with hits_all as (
select memberid,count(*) as count from orders group by memberid
),
hits_true as
(select memberid,count(*) as count from orders where hit = true group by memberid)
select
*
from
hits_true
inner join
hits_all on
hits_all.memberid = hits_true.memberid
and hits_all.count = hits_true.count;
+----------+-------+----------+-------+
| memberid | count | memberid | count |
+----------+-------+----------+-------+
| 10 | 2 | 10 | 2 |
+----------+-------+----------+-------+
You use group by and having as follows:
select customer_id
from orders
group by customer_id
having sum(delivered_on_time) = count(*)
This works because an ontime delivery is identified by delivered_on_time = 1. So you can just ensure that the sum of delivered_on_time is equal to the number of records for the customer.
You can use aggregation and having:
select customer_id
from orders
group by customer_id
having min(delivered_on_time) = max(delivered_on_time);
I got those two tables sport and student:
First table sport:
|idsport | name |
_______________________
| 1 | bobsled |
| 2 | skating |
| 3 | boarding |
| 4 | iceskating |
| 5 | skiing |
Second table student:
foreign key
|idstudent | name | sport_idsport
__________________________________________
| 1 | john | 3 |
| 2 | pauly | 2 |
| 3 | max | 1 |
| 4 | jane | 2 |
| 5 | nico | 5 |
so far i did this it output which number is mostly inserted, but cant get it to work
with two tables
SELECT sport_idsport
FROM (SELECT sport_idsport FROM student GROUP BY sport_idsport ORDER BY COUNT(*) desc)
WHERE ROWNUM<=1;
I need to output name of most popular sport, in that case it would be skating.
I use oracle sql.
with counter as (
Select sport_idsport,
count(*) as cnt,
dense_rank() over (order by count(*) desc) as rn
from student
group by sport_idsport
)
select s.*, c.cnt
from sport s
join counter c on c.sport_idsport = s.idsport and c.rn = 1;
SQLFiddle example: http://sqlfiddle.com/#!4/b76e21/1
select cnt, sport_idsport from (
select count(*) cnt, sport_idsport
from student
group by sport_idsport
order by count(*) desc
)
where rownum = 1
I have 2 tables with similar layout, involving INCOME and EXPENSES.
The id column is a customer ID.
I need a result of customer TOTAL AMOUNT, summing up income and expenses.
Table: Income
| id | amountIN|
+--------------+
| 1 | a |
| 2 | b |
| 3 | c |
| 4 | d |
Table: Expenses
| id | amountOUT|
+---------------+
| 1 | -x |
| 4 | -z |
My problem is that some customers only have expenses and others just income... so cannot know in advance id I need to do a LEFT or RIGHT JOIN.
In the example above an RIGHT JOIN could do the trick, but if the situation is inverted (more customers on the Expenses table) it doesn't work.
Expected Result
| id | TotalAmount|
+--------------+
| 1 | a - x |
| 2 | b |
| 3 | c |
| 4 | d - z |
Any help?
select id, SUM(Amount)
from
(
select id, amountin as Amount
from Income
union all
select id, amountout as Amount
from Expense
) a
group by id
I believe a full join will solve your problem.
I would approach this as a union. Do that in your subquery then sum on it.
For instance:
select id, sum(amt) from
(
select i.id, i.amountIN as amt from Income i
union all
select e.id, e.amountOUT as amt from Expenses e
)
group by id
You should really have another table like client :
Table: Client
| id |
+----+
| 1 |
| 2 |
| 3 |
| 4 |
So you could do something like that
SELECT Client.ID, COALESCE(Income.AmountIN, 0) - COALESCE(Expenses.AmountOUT, 0)
FROM Client c
LEFT JOIN Income i ON i.ID = c.ID
LEFT JOIN Expense e ON e.ID = c.ID
Will be less complicated and i'm sure it will come handy another time :)