Project is generated with seam-gen. Following setup works fine but I am confused with the generated SQL.
I have the following tables. ------------------------------- User Patient Doctor Supervisor
Respective hibernate objects --------------------------------- @Entity @Table(name = "user") @Inheritance(strategy = InheritanceType.JOINED) User @Entity @Table(name = "producer") Patient extends User // id is not defined here. @Entity @Table(name = "producer") Doctor extends User // id not defined @Entity @Table(name = "producer") Supervisor extends User // id not defined
When I load Patient list, I see a join between a patient class and user class which totally makes sense. But when I view User list, I see the following SQL.
select user0_.id as id0_, user0_.email as email0_, user0_.passwd as passwd0_, user0_.first_name as first4_0_, user0_.last_name as last5_0_, user0_.gender as gender0_, user0_.dob as dob0_, user0_.phone as phone0_, user0_.fax as fax0_, user0_1_.contact_name as contact3_1_, user0_1_.contact_phone as contact4_1_, user0_1_.contact_email as contact5_1_, user0_1_.contact_fax as contact6_1_, user0_1_.display_order as display11_1_, user0_2_.contact_name as contact3_2_, user0_2_.contact_phone as contact4_2_, user0_2_.contact_email as contact5_2_, user0_2_.contact_fax as contact6_2_, user0_2_.status as status2_, user0_2_.display_order as display11_2_, user0_3_.status as status6_, user0_3_.contact_name as contact4_6_, user0_3_.contact_phone as contact5_6_, user0_3_.contact_email as contact6_6_, user0_3_.contact_fax as contact7_6_, case when user0_1_.id is not null then 1 when user0_2_.id is not null then 2 when user0_3_.id is not null then 3 when user0_.id is not null then 0 end as clazz_ from user user0_ left outer join doctor user0_1_ on user0_.id=user0_1_.id left outer join patient user0_2_ on user0_.id=user0_2_.id left outer join supervisor user0_3_ on user0_.id=user0_3_.id limit ?
Why is it doing a left outer join with doctor, patient and supervisor entities when I load user list? Is this the normal behavior? If it is, what should I do to prevent the joins and only load user list? I guess this makes sense for other inheritance strategies.