Q&A for anime and manga fans
select * from ( select * from Posts where tags like '%smartcontracts%' or tags like '%solidity%' or tags like'%ethereum%' ) as first inner join ( select * from Comments where Id in (select Id from Posts where tags like '%smartcontracts%' or tags like '%solidity%' or tags like'%ethereum%') ) as second on first.Id = second.PostId