Solved

SQL: how to sequence parent records by child rankings

Posted on 2008-10-07
3
208 Views
Last Modified: 2012-05-05
I am looking for some help in creating a simple SQL query to retrieve records from two related tables.

The tables (in simplified form) are as follows:

CREATE TABLE parent (
 primary_key integer,
 name varchar(20),
 PRIMARY KEY (primary_key)
);

CREATE TABLE child (
 primary_key integer,
 parent_key integer,
 name varchar(20),
 age integer,
 PRIMARY KEY (primary_key)
);

I need to select records from the parent table that have at least one child, ordered by the age of the oldest child.

It seems a simple enough challenge but I have been unable to crack it. I hope somebody can help.

Many thanks,
Tim
0
Comment
Question by:Tim85
3 Comments
 
LVL 143

Accepted Solution

by:
Guy Hengel [angelIII / a3] earned 125 total points
ID: 22657108
this should do:
select p.name, max(c.age) oldest_child_age
  from parent p
  join child c
    on c.parent_key = p.primary_key
 group by p.primary_key, p.name
 order by max(c.age) desc

Open in new window

0
 
LVL 37

Assisted Solution

by:momi_sabag
momi_sabag earned 125 total points
ID: 22657109
select t1.name
from parent t1 inner join
 (select count(*) as cnt, max(age) as maxage, parent_key from child group by parent_key) t2
 on t1.primary_key = t2.parent_key)
order by t2.maxage desc
0
 
LVL 1

Author Closing Comment

by:Tim85
ID: 31503728
Thanks to both of you for your extremely quick response. I have split the points, since each of you proposed a solution that works. Thanks again.
0

Featured Post

Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

If you have heard of RFC822 date formats, they can be quite a challenge in SQL Server. RFC822 is an Internet standard format for email message headers, including all dates within those headers. The RFC822 protocols are available in detail at:   ht…
Occasionally there is a need to clean table columns, especially if you have inherited legacy data. There are obviously many ways to accomplish that, including elaborate UPDATE queries with anywhere from one to numerous REPLACE functions (even within…
Via a live example, show how to set up a backup for SQL Server using a Maintenance Plan and how to schedule the job into SQL Server Agent.
Viewers will learn how to use the INSERT statement to insert data into their tables. It will also introduce the NULL statement, to show them what happens when no value is giving for any given column.

685 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question