Get rows results sorted by 2 columns with Wordpress $wpdb

Question

I have 'transactions' table:

id user amount currency plan_id
1   1     11     usd      1
2   1     9      usd      2
3   1     10     usd      2
4   2     10     usd      7
5   1     7      eur      3
6   1     5      eur      3
7   1     6      eur      4
8   3     3      usd      8

I would like to get the sum of the amounts sorted by currency and then plan_id per given user: $results[currency][plan_id]

$results['usd'][1] = 11
$results['usd'][2] = 19
$results['eur'][3] = 12
$results['eur'][4] = 6

so far I have:

$query = '
    SELECT plan_id, currency, SUM( amount ) as earnings
    FROM transactions
    WHERE user = 1
    GROUP BY currency, plan_id
';
$results = $wpdb->get_results( $query, OBJECT_K );

But it is returning just rows sorted regularly by plan_id ignoring the sorting by currency:

Array ( [1] => stdClass Object ( [plan_id] => 1 [currency] => usd [earnings] => 11 ) [2] => stdClass Object ( [plan_id] => 2 [currency] => usd [earnings] => 19 ) [3] => stdClass Object ( [plan_id] => 3 [currency] => eur [earnings] => 12 ) [7] => stdClass Object ( [plan_id] => 7 [currency] => eur [earnings] => 6 ) ) 

Is it even possible to do with $wpdb?

Please help. Thanks

Answer 1

You need to tell MySQL how to sort the results using the ORDER BY clause (missing in your query).

This will yield the results you're looking for:

SELECT `plan_id`, `currency`, SUM( `amount` ) AS `earnings`
FROM `transactions`
WHERE `user` = 1
GROUP BY `currency`, `plan_id`
ORDER BY `currency` DESC, `plan_id` ASC