SQL and Coldfusion left join tables getting duplicate results as a list in one column

Question

lets say I have two tables: Persons (P_Id, Name) and Orders (O_Id, OrderNo, P_Id)... I want to do a left join which would be:

SELECT Persons.Name, Orders.OrderNo         


        

Answer 1

Look up FOR XML - that will let you pivot the order numbers.

Check this out

With Person AS
(
    Select 1 PersonId, 'John' PersonName
    Union Select 2, 'Jane'
),
Orders As
(
    Select 1 OrderId, 1 PersonId, Convert (DateTime, '1/1/2011') OrderDate
    Union Select 2, 1 , Convert (DateTime, '1/2/2011')
    Union Select 3, 1 , Convert (DateTime, '1/5/2011')
    Union Select 4, 1 , Convert (DateTime, '1/7/2011')
    Union Select 5, 1 , Convert (DateTime, '1/9/2011')
    Union Select 6, 2 , Convert (DateTime, '1/2/2011')
    Union Select 7, 2 , Convert (DateTime, '1/5/2011')
    Union Select 8, 2 , Convert (DateTime, '1/7/2011')
)
Select PersonId, 
(
    Select STUFF((SELECT  ', ' + cast(O.OrderId as nvarchar)
    FROM Orders O
    Where 1=1
        And O.PersonId = Person.PersonId
    FOR XML PATH('')), 1, 1, '') 
) OrderList
From Person

The output is

PersonId    OrderList
----------- -----------------------
1            1, 2, 3, 4, 5
2            6, 7, 8

(2 row(s) affected)