The query result is used as a condition for conditional query with another table, and the result used as a query condition for other tables also appears in the final result set.

  mysql, question

The result of table A query is used as the condition of table B query.
The result of table B query is used as the condition of table C query.
The final result set consists of the query results of A, B and C tables respectively

select c from C inner join ( select b from B inner join select a  from A on B.b=A.a )  on C.c= B.b;
 
 Parting line  ............
 
 select A.a,B.b,C.c from (select c   from  C where c-column= (select b from B where  b-column = (select a  from A ));

The former is an inner koin join query and the latter is a from subquery.
The former is recommended.

I haven’t tried either of the two pieces of code, which may have been written incorrectly. Welcome to give directions