java - jOOQ can I fetch a join of two tables into the respective POJOs -

in jooq if want fetch row of table jooq autogenerated pojos do, instance:

dsl.selectfrom(user)                 .where(user.u_email.equal(email))                 .fetchoptionalinto(user.class); 

now, suppose want join between 2 tables, e.g. user , role, how can fetch result pojos these 2 tables?

this 1 solution using resultquery.fetchgroups(recordmapper, recordmapper)

map<userpojo, list<rolepojo>> result = dsl.select(user.fields())    .select(role.fields())    .from(user)    .join(user_to_role).on(user.user_id.eq(user_to_role.user_id))    .join(role).on(role.role_id.eq(user_to_role.role_id))    .where(user.u_email.equal(email))    .fetchgroups(         // map records first user table , key pojo type        r -> r.into(user).into(userpojo.class),         // map records first role table , value pojo type        r -> r.into(role).into(rolepojo.class)    ); 

note, if want use left join instead (in case user not have roles, , want empty list per user), you'll have translate null roles empty lists yourself.

make sure have activated generating equals() , hashcode() on pojos in order able put them in hashmap keys:

<pojosequalsandhashcode>true</pojosequalsandhashcode>