Question

I have three domain objects defined as :

class Member {
    String name

    static constraints = {}
    static belongsTo=[community:Community]
}

class Community {
    String leaderName
    String code

    static constraints = {}
    static hasMany=[members: Member]
    static belongsTo=[bank:Bank]
}

class Bank {

    String bankName
    static hasMany=[communities: Community]
    static constraints = {}
}

When I tried to initialize these domain objects with some test data in BootStrap.groovy config class as :

 def init = { servletContext ->

            def m1 = new Member(name:"M1_Name")
            def m2 = new Member(name:"M2_Name")
            def m3 = new Member(name:"M3_Name")

            m1.save(failOnError:true)
            m2.save(failOnError:true)
            m3.save(failOnError:true)

            def comA = new Community(leaderName:"LeaderA", code:"AA")
            def comB = new Community(leaderName:"LeaderB", code:"BB")

            comA.addToMembers(m1)
            comA.addToMembers(m2)
            comB.addToMembers(m3)

            comA.save(failOnError:true)
            comB.save(failOnError:true)

            def bankA = new Bank(bankName:"BankA")
            def bankB = new Bank(bankName:"BankB")

            bankA.addToCommunities(comA)
            bankB.addToCommunities(comB)

            bankA.save(failOnError:true)
            bankB.save(failOnError:true)
        }

I am getting following error :

| Loading Grails 2.0.4
| Configuring classpath.
| Environment set to development.....
| Packaging Grails application.....
| Compiling 3 source files.....
| Running Grails application
| Error 2012-07-13 22:14:44,798 [pool-5-thread-1] ERROR context.GrailsContextLoader  - Error executing bootstraps: Validation Error(s) occurred during save():
- Field error in object 'mygrailtests.Member' on field 'community': rejected value [null]; codes [mygrailtests.Member.community.nullable.error.mygrailtests.Member.community,mygrailtests.Member.community.nullable.error.community,mygrailtests.Member.community.nullable.error.mygrailtests.Community,mygrailtests.Member.community.nullable.error,member.community.nullable.error.mygrailtests.Member.community,member.community.nullable.error.community,member.community.nullable.error.mygrailtests.Community,member.community.nullable.error,mygrailtests.Member.community.nullable.mygrailtests.Member.community,mygrailtests.Member.community.nullable.community,mygrailtests.Member.community.nullable.mygrailtests.Community,mygrailtests.Member.community.nullable,member.community.nullable.mygrailtests.Member.community,member.community.nullable.community,member.community.nullable.mygrailtests.Community,member.community.nullable,nullable.mygrailtests.Member.community,nullable.community,nullable.mygrailtests.Community,nullable]; arguments [community,class mygrailtests.Member]; default message [Property [{0}] of class [{1}] cannot be null]

Message: Validation Error(s) occurred during save():
- Field error in object 'mygrailtests.Member' on field 'community': rejected value [null]; codes [mygrailtests.Member.community.nullable.error.mygrailtests.Member.community,mygrailtests.Member.community.nullable.error.community,mygrailtests.Member.community.nullable.error.mygrailtests.Community,mygrailtests.Member.community.nullable.error,member.community.nullable.error.mygrailtests.Member.community,member.community.nullable.error.community,member.community.nullable.error.mygrailtests.Community,member.community.nullable.error,mygrailtests.Member.community.nullable.mygrailtests.Member.community,mygrailtests.Member.community.nullable.community,mygrailtests.Member.community.nullable.mygrailtests.Community,mygrailtests.Member.community.nullable,member.community.nullable.mygrailtests.Member.community,member.community.nullable.community,member.community.nullable.mygrailtests.Community,member.community.nullable,nullable.mygrailtests.Member.community,nullable.community,nullable.mygrailtests.Community,nullable]; arguments [community,class mygrailtests.Member]; default message [Property [{0}] of class [{1}] cannot be null]

   Line | Method
->>  13 | doCall                           in BootStrap$_closure1
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
|   301 | evaluateEnvironmentSpecificBlock in grails.util.Environment
|   294 | executeForEnvironment . . . . .  in     ''
|   270 | executeForCurrentEnvironment     in     ''
|   303 | innerRun . . . . . . . . . . . . in java.util.concurrent.FutureTask$Sync
|   138 | run                              in java.util.concurrent.FutureTask
|   886 | runTask . . . . . . . . . . . .  in java.util.concurrent.ThreadPoolExecutor$Worker
|   908 | run                              in     ''
^   662 | run . . . . . . . . . . . . . .  in java.lang.Thread

Here, line 13 is

m1.save(failOnError:true)

Could you please suggest me what’s wrong going on? Or what I am missing.

UPDATE :
It is working without errors when I remove belongsTo relation in Member and Community objects.

Answer 1

When you add the belongsTo: Community part to Member you are saying that Member will belong to a Community.

When you construct the Member object, you are not providing the Community that is connected with the Member. Committing the Member like this is blowing up because you haven’t yet said the Community it belongs to.

You don’t need those save calls there anyway, as belongsTo marks that Community will be responsible for the save. Take out the 3 m[x].save() lines, readd the belongsTo code and see if it works as expected.