Answers for "how to select from a select statement sql"

sql select from select

SELECT t1.*
FROM   t1
WHERE  t1.MY_FIELD = (SELECT  t2.MY_FIELD
                   FROM    t2
                   WHERE   t2.MY_FIELD = t1.MY_FIELD);

select in select sql

SELECT column1 = (SELECT column-name FROM table-name WHERE condition),       column-names  FROM table-name WEHRE condition