Order by Lastname and ID - sql

Question

I have two DB tables
FAMILY
------
family_id (PK)
address
....
PERSON
-----
person_id (PK)
lastname
birthday
family_id (FK)
family_role (numeric >1 male, 2 female, 3 male(child), 4 female(child)
....
I want to create an alphabetic family list, in which the lastname of the oldest person must be leading and ordered by the FAMILY_ROLE. I was trying something like:
select *
from person, family
where person.family_id = family.family_id
order by lastname, family_role
Now this is not working, because last names in the same family doesn't have to be the same. So this is working
select *
from person, family
where person.family_id = family.family_id
order by family_id, family_role
But that doesn't give me an alphabetic list.
The output must be something like:
Test street 1 - New York (family_id = 100)
John Bla (family_id = 100 | person_id =10 | family_role=1)
Sara Bla (family_id = 100 | person_id =13 | family_role=2)
----
Apple street 1 - New York (family_id = 45)
Rick Cha (family_id = 45 | person_id =1 | family_role=1)
Lin Cha (family_id = 45 | person_id =5 | family_role=2)
Jean App (family_id = 45 | person_id =3 | family_role=4)
----
Cherry street 114 - New York (family_id = 23)
Becky Cha (family_id = 23 | person_id =122 | family_role=2)
----
Can someone help me? Database version MSSQL 2008.
Also please keep in mind that people can have the same last name, but belong in a different family (see the Cha families in the output example).
Thanks!

Answer 1

You need a way to associate the last name of the oldest person in a family with everyone in the family. You can use ROW_NUMBER() in a cte/subquery for this:
;with cte AS (SELECT *,ROW_NUMBER() OVER(PARTITION BY Family_ID ORDER BY Age DESC) AS RN
FROM Person
)
SELECT p.*,f.*
FROM person p
JOIN family f
ON p.family_id = f.family_id
JOIN cte
ON p.family_id = cte.Family_ID
AND cte.RN = 1
ORDER BY cte.lastname
The ROW_NUMBER() function assigns a number to each row. PARTITION BY is optional, but used to start the numbering over for each value in that group, ie: if you PARTITION BY Family_ID then for each unique Family_ID value the numbering would start over at 1. ORDER BY of course is used to define how the counting should go, and is required in the ROW_NUMBER() function.
So the cte/subquery gives you a way to see who the oldest person is and access their last name in one step, then you can JOIN to this to use in your ORDER BY.
Note: Old-style joins should also be avoided, and so I updated that as well, and I'm assuming you have an Age field in your Person table to determine who the oldest is, the cte may require updating based on actual table structure.

Answer 2

Well, you have to decide how you are going to choose which family member is going to determine the alphabetical placement of the family. For example if family #100 has Jon Doe and Jane Smith, will it come in the Ds alphabetically or the Ss?
You could write the query like this
SELECT f.*,p.*,A.FamilyNameOrderKey FROM
(
SELECT
Min(lastname) As FamilyNameOrderKey, Family_id
FROM
person
Group by Family_id
) As A
INNER JOIN
family f
ON
A.family_id = f.family_id
INNER JOIN
people p
ON
p.family_id = f.family_id
)
Order by A.FamilyNameOrderKey
This will sort by the last name of the alphabetically first last name in each family