gorm - Cant access grails one to many relationship data -

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i asking dump question new 1 grails.

i have 2 domain school , classes

class school { static hasmany = [ classes: classes ] }

and

class classes { static belongsto = [school]    }

now can not data - if 's' school have c1,c2,c3 classes check 2 ways get.

1. classesinstancelist = classes.findallbyschool(s)

it returns null;

2. classesinstancelist = s.getclasses();

it returns follwing error message

message: failed lazily initialize collection of role: com.test.school.classes, no session or session closed

please suggest can do. stucked . why first 1 not work please explain someone.

you can create reference classes domain school , search school object. 

class classes {     static belongsto = [school:school]     static constraints = {} }   class school {     static hasmany = [ classes: classes ]     static constraints = {}     string tostring(){"$id"} }

test:

def s = new school() def c = new classes()  s.addtoclasses(c) s.save(flush:true)  println classes.findallbyschool(s)

this should give classes related school.


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