cascade delete with many-to-many mapping in Grails

Question

I have problem about many-to-many mapping.

[Case]

• Account owns Community(owner)
• Community has many Account(members)

When I delete instance of Community, owner account is also delete.

I don't expect owner account to be removed.

My mapping is wrong?

[Domain Class]

class Account {

String name

static hasMany = [communities: Community]
static belongsTo = [Community]
}

class Community {

String name
Account owner

static hasMany = [members: Account]
}

[TestCode]

def admin = new Account(name: 'admin').save(flush:true)
def user = new Account(name: 'user').save(flush:true)

def c = new Community(name: 'TestCommunity')

c.owner = admin

c.addToMembers(admin)
c.addToMembers(user)            
c.save(flush:true)

c.removeFromMembers(user)
c.save(flush:true)

c.delete(flush:true)

[Hibernate Log]

Hibernate: insert into account (id, version, name) values (null, ?, ?)
Hibernate: insert into community (id, version, name, owner_id) values (null, ?, ?, ?)
Hibernate: update account set version=?, name=? where id=? and version=?
Hibernate: insert into community_members (community_id, account_id) values (?, ?)
Hibernate: update account set version=?, name=? where id=? and version=?
Hibernate: update community set version=?, name=?, owner_id=? where id=? and version=?
Hibernate: delete from community_members where community_id=? and account_id=?
Hibernate: delete from community_members where community_id=?
Hibernate: delete from community where id=? and version=?
Hibernate: delete from account where id=? and version=?          <== not expected !!

Answer 1

You have to provide hibernate equivalent to on delete set null mapping

There is already a question about it. Please refer to it for further details How do I override the cascade delete for a relation in Grails GORM?