Get the highest odds from the last update - sql

Question

I have these tables in a PostgreSQL database:
bookmakers
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| id | name |
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| 1 | Unibet |
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| 2 | 888 |
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odds
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| id | odds_type | odds_index | bookmaker_id | created_at |
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| 1 | 1 | 1.55 | 1 | 2012-06-02 10:30 |
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| 2 | 2 | 3.22 | 2 | 2012-06-02 10:30 |
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| 3 | X | 3.00 | 1 | 2012-06-02 10:30 |
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| 4 | 2 | 1.25 | 1 | 2012-05-27 09:30 |
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| 5 | 1 | 2.30 | 2 | 2012-05-27 09:30 |
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| 6 | X | 2.00 | 2 | 2012-05-27 09:30 |
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What I am trying to query is the following:
Give me the 1/X/2 odds from the latest update (created_at) from ALL bookmakers and from that last update, give me the highest odds for each odds_type ('1', '2', 'X').
On my website I display them as:
Best odds right now: 1 | X | 2
--------------------
2.30 | 3.00 | 3.22
I have to first get the latest, because the odds from the update from yesterday are no longer valid. Then from that last update, I have - in this case - 2 odds from 2 different bookmakers, so I need to get the best one for type '1','2','X'.
Pseudo SQL would be something like:
SELECT MAX(odds_index) WHERE odds_type = '1' ORDER BY created_at DESC, odds_index DESC
But that doesn't work, because I would always get the latest odds (and not the highest/best from those latest)
I hope I'm making sense.

Answer 1

Subqueries to the rescue!
select o1.odds_type, max(o1.odds_index)
from odds o1
inner join (select odds_type, max(created_at) as created_at
from odds group by odds_type) o2
on o1.odds_type = o2.odds_type
and o1.created_at = o2.created_at
group by o1.odds_type
SQLFiddle: http://sqlfiddle.com/#!3/47df4/3

Answer 2

Your words "from the last update" contradict your example. Here are two methods.
To get from last update, how about getting the max created_at date aka last update and then using it for the rest.
declare #max_date date
select #max_date = max(created_at) from odds
select odds_type, odds_index
from odds
where created_at = #max_date
Or to match your example
select odds_type, odds_index
from odds
group by odds_type
having created_at = max(created_at)
Note: Different DBMS give different results depending on the select columns and whether there are more columns than in the group by clause.