ipv4_prefixes,asn JSON_ARRAYAGG

SELECT a.asn,JSON_ARRAYAGG(JSON_OBJECT('prefix',a.prefix,'name',pfname,'description',pfdescr,'country_code',cc,'parent',JSON_OBJECT()) )  ipv4_prefixes FROM _riswhois1 a
JOIN prefixes b ON a.i1=b.i AND a.prefix=b.prefix
WHERE a.asn IN (1901,8447,8412,6830,3320)
GROUP BY a.asn;