SQL Update query with group by clause

Question

I have changed the script from Derek and it works for me now:

UPDATE table1 AS t 
INNER JOIN 
(SELECT type,max(age) mage FROM table1 GROUP BY type) t1 
ON t.type = t1.type AND t.age = t1.mage 
SET name='HIGH'

You can't use group by directly in an update statement. It'll have to look more like this:

update t
set name='HIGH'
from table1 t
inner join (select type,max(age) mage from table1 group by type) t1
on t.type = t1.type and t.age = t1.mage;

Since I looked-up this response and found it a little bit confusing to read, I experimented to confirm that the following query does work, confirming Svetlana's highly-upvoted original post:

update archives_forum f
inner join ( select forum_id, 
    min(earliest_post) as earliest, 
    max(earliest_post) as latest 
  from archives_topic 
    group by forum_id 
  ) t 
  on (t.forum_id = f.id)
set f.earliest_post = t.earliest, f.latest_post = t.latest;

Now you know ... and so do I.

You can use a semi-join:

SQL> UPDATE table1 t_outer
  2     SET NAME = 'HIGH'
  3   WHERE age >= ALL (SELECT age
  4                       FROM table1 t_inner
  5                      WHERE t_inner.type = t_outer.type);

3 rows updated

SQL> select * from table1;

NAME             TYPE AGE
---------- ---------- ----------
HIGH                1 23
HIGH                2 26
HIGH                3 29
Raju                2 23
Babu                1 21
Muthu               3 27

6 rows selected

Your query won't work because you can't compare an aggregate and a column value directly in a group by query. Furthermore you can't update an aggregate.