Retrieving records with inner joins - sql

Question

My assignment is to get the the First name, Middle name and Last name for all Customers that have had an order before '2012-09-30' and after '2013-09-30'. I'm using the AdventureWorks2017 as a sample DB
Table: Sales.SalesOrderHeader
[SalesOrderID]
,[RevisionNumber]
,[OrderDate]
,[DueDate]
,[ShipDate]
,[Status]
,[OnlineOrderFlag]
,[SalesOrderNumber]
,[PurchaseOrderNumber]
,[AccountNumber]
,[CustomerID]
,[SalesPersonID]
,[TerritoryID]
,[BillToAddressID]
,[ShipToAddressID]
,[ShipMethodID]
,[CreditCardID]
,[CreditCardApprovalCode]
,[CurrencyRateID]
,[SubTotal]
,[TaxAmt]
,[Freight]
,[TotalDue]
,[Comment]
,[rowguid]
,[ModifiedDate]
Table: Person.Person
[BusinessEntityID]
,[PersonType]
,[NameStyle]
,[Title]
,[FirstName]
,[MiddleName]
,[LastName]
,[Suffix]
,[EmailPromotion]
,[AdditionalContactInfo]
,[Demographics]
,[rowguid]
,[ModifiedDate]
Table: Sales.Customers
[CustomerID]
,[PersonID]
,[StoreID]
,[TerritoryID]
,[AccountNumber]
,[rowguid]
,[ModifiedDate]
My Query
SELECT DISTINCT person_table.FirstName,
person_table.MiddleName,
person_table.LastName
FROM Sales.SalesOrderHeader as sales_order_table
inner join Sales.Customer as sales_customer_table
on (sales_customer_table.CustomerID = sales_order_table.CustomerID
and sales_order_table.OrderDate <= '2012-09-30' )
inner join Sales.Customer as sales_customer_table2
on (sales_customer_table2.CustomerID = sales_order_table.CustomerID
and sales_order_table.OrderDate >= '2013-06-30' )
inner join Sales.Customer as match_result
on (match_result.CustomerID = sales_customer_table2.CustomerID)
inner join Person.Person as person_table
on (person_table.BusinessEntityID = match_result.PersonID)
In this current state returns no rows and im unsure where the problem is
[UPDATE]
Found a relatevly good solution to the problem by editing Bilal Fakih answer
SELECT DISTINCT person_table.FirstName,
person_table.MiddleName,
person_table.LastName,
count(*) as Total_Instanses
FROM Sales.SalesOrderHeader as sales_order_table
inner join Sales.Customer as sales_customer_table
on (sales_customer_table.CustomerID = sales_order_table.CustomerID)
inner join Person.Person as person_table
on (person_table.BusinessEntityID = sales_customer_table.PersonID)
WHERE sales_order_table.OrderDate NOT BETWEEN '2012-09-30' AND '2013-06-30'
GROUP BY person_table.FirstName,
person_table.MiddleName,
person_table.LastName
HAVING count(*) >= 2
The suggestion was good but it woud return records that only had one instance. Im running into a few corner cases now. For example If a person has made 2 Orders that are bewfore 2012 or after 2013 will still be shown. The result im looking for is for a person to show up only when he has made orders before AND after the given dates

Answer 1

Try this, I'm not sure if it works I don't have the dataset to test, but it should
SELECT DISTINCT person_table.FirstName,
person_table.MiddleName,
person_table.LastName
FROM Sales.SalesOrderHeader as sales_order_table
inner join Sales.Customer as sales_customer_table
on (sales_customer_table.CustomerID = sales_order_table.CustomerID
inner join Person.Person as person_table
on (person_table.BusinessEntityID = match_result.PersonID)
WHERE sales_order_table.OrderDate NOT BETWEEN '2012-09-30' AND '2013-06-30'

Answer 2

You could simply this using below. Also your dates filter was not correct.
SELECT DISTINCT p.FirstName,
p.MiddleName,
p.LastName
FROM Sales.SalesOrderHeader as s
INNER JOIN Sales.Customer as c
ON c.CustomerID = s.CustomerID
INNER JOIN Person.Person as p
ON p.BusinessEntityID = c.PersonID)
WHERE s.OrderDate >= '2012-09-30' <----- add this
AND s.OrderDate <= '2013-06-30' ) ---- and this

Answer 3

My assignment is to get the the First name, Middle name and Last name for all Customers that have had an order before '2012-09-30' and after '2013-09-30'.
One method uses aggregation:
SELECT p.FirstName, p.MiddleName, p.LastName
FROM person_table p JOIN
Sales.Customer c
ON p.BusinessEntityID = c.PersonID JOIN
Sales.SalesOrderHeader so
ON c.CustomerID = so.Cus tomerID
GROUP BY p.FirstName, p.MiddleName, p.LastName
HAVING MIN(so.OrderDate) < '2020-09-30' AND
MAX(so.OrderDate) >'2013-06-30';
I will say that this condition looks suspicious:
ON p.BusinessEntityID = c.PersonID
However, that is what you use in your query. I would expect the person table to have an id called something like PersonId.