grails，关系和级联删除

Question

I have the following domain classes:

class Patient {
    ...
}

class Receipt{
@NotNull
static belongsTo = [patient:Patient]
...
}

If I try to delete a Patient instance (after creation of Receipt instances), I have a MySQLIntegrityConstraintViolationException . Notice that a patient can have zero-to-many receipts.

Answer 1

To complete the parent child relationship, create a has many section in the parent domain class:

class Patient {
static hasMany = [receipts: Receipt]
    ...
}

class Receipt{
@NotNull
static belongsTo = [patient:Patient]
...
}