PDO fetch second column as key of second array - php

Question

I have an SQL query :
SELECT
DATE,
ID_DOMAIN,
SUM(CLICKS) AS CLICKS,
SUM(ADS) AS ADS,
SUM(CONVERSION) AS CONVERSION,
FROM website_stats
WHERE ID_USER_PRODUCT_DIFFUSER = :id_user_product_diffuser
AND DATE >= :date_begin
AND DATE <= :date_end
AND ID_DOMAIN != 0
GROUP BY DATE, ID_DOMAIN;
In my PDO fetchAll, I use $sth->fetchAll(PDO::FETCH_ASSOC | PDO::FETCH_GROUP). Then I have this output :
array(2) {
["2018-09-14"]=>
array(2) {
[0]=>
array(4) {
["ID_DOMAIN"]=>
string(1) "7"
["CLICKS"]=>
string(4) "1092"
["ADS"]=>
string(4) "1070"
["CONVERSION"]=>
string(3) "269"
}
[1]=>
array(4) {
["ID_DOMAIN"]=>
string(1) "9"
["CLICKS"]=>
string(3) "459"
["ADS"]=>
string(3) "452"
["CONVERSION"]=>
string(2) "56"
}
}
["2018-09-15"]=>
array(2) {
[0]=>
array(4) {
["ID_DOMAIN"]=>
string(1) "7"
["CLICKS"]=>
string(3) "914"
["ADS"]=>
string(3) "880"
["CONVERSION"]=>
string(3) "166"
}
[1]=>
array(4) {
["ID_DOMAIN"]=>
string(1) "9"
["CLICKS"]=>
string(3) "365"
["ADS"]=>
string(3) "361"
["CONVERSION"]=>
string(2) "57"
}
}
}
But for my code, I need the ID_DOMAIN a key in my sub array. It's possible without looping ? I means, just with PDO::FETCH* ? In fact, I need an array just like this :
array(2) {
["2018-09-14"]=>
array(3) {
[7]=>
array(3) {
["CLICKS"]=>
string(4) "1092"
["ADS"]=>
string(4) "1070"
["CONVERSION"]=>
string(3) "269"
}
[9]=>
array(3) {
["ID_DOMAIN"]=>
string(1) "9"
["CLICKS"]=>
string(3) "459"
["ADS"]=>
string(3) "452"
["CONVERSION"]=>
string(2) "56"
}
}
["2018-09-15"]=>
array(2) {
[7]=>
array(3) {
["ID_DOMAIN"]=>
string(1) "7"
["CLICKS"]=>
string(3) "914"
["ADS"]=>
string(3) "880"
["CONVERSION"]=>
string(3) "166"
}
[9]=>
array(3) {
["CLICKS"]=>
string(3) "365"
["ADS"]=>
string(3) "361"
["CONVERSION"]=>
string(2) "57"
}
}
}
I search for the good PDO fetch mode for long time but it seems like nobody has this problem in this website :/
Thank you in advance :)