sql - Join without specyfing primary and foreign key -
is possible (ex. in ms sql) perform join in way this:
select p.* person p join order o   by default db engine relation between tables , use without writing additional:
on p.id = o.fk_person      
no need specify join clause in on of 2 ways.
implicit join notation:
select p.*  person p, order o p.id = o.fk_person   or explicit join notation:
select p.*  person p inner join order o         on p.id = o.fk_person   if won't specify join order, no server join anything. it's defined in sql standard.
Comments
Post a Comment