Question

Scenario 1:
I have two classes:

Post:

class Post {
String content
Date dateCreated
static constraints = {
content(blank: false)
}
static belongsTo = [ user : User ]
}

User:

class User {
// existing code here
static hasMany = [ posts : Post ]
}

Its a classical one-many relationship. The integration test for these classes:

void testFirstPost() {
def user = new User(userId: 'joe',password: 'secret').save()
def post1 = new Post(content: "First post... W00t!")
user.addToPosts(post1)
def post2 = new Post(content: "Second post...")
user.addToPosts(post2) }

Works very well. But if you consider the other two classes like:

Scenario 2:

User:

class User {
    String login
    String password
    Profile profile
    Status status
    static hasMany = [ holidays : Holiday ]
    static constraints = { 
        login(unique:true,size:2..20)
        password(size:2..20) //more to be added later!
        profile(nullable:true)
        company(nullable:true)
    }
    static belongsTo = [ company : Company ]
}

Company:

class Company {
    String shortName;
    String name 
    Date dateCreated
    String region
    String email
    Address address
    Status status   
    Long tel
    Long fax
    static hasMany = [ users : User]
        static constraints = {
        }
    static mapping = {
        address lazy:false
        status lazy:false
    }
}

Again the classical one-many relationship.

For these classes, I have written the test like this:

void testSaveUser() {
        def status1 = new Status(name:"Busy")
        status1.save(flush:true)        
        def user = new User(login:"anto",password:"anything",
            status:status1)
        assert user.save(flush:true, failOnError: true)
    }

Even this test works fine. Note that in second User class, I have made the constraint for company field as company(nullable:true), if I didn’t put this the above test(testSaveUser()) fails!.

The error I’m getting is this:

Validation Error(s) occurred during save(): - Field error in object 'mnm.User' on field 'company': rejected value [null]; codes [mnm.User.company.nullable.error.mnm.User.company,mnm.User.company.nullable.error.company,mnm.User.company.nullable.error.mnm.Company,mnm.User.company.nullable.error,user.company.nullable.error.mnm.User.company,user.company.nullable.error.company,user.company.nullable.error.mnm.Company,user.company.nullable.error,mnm.User.company.nullable.mnm.User.company,mnm.User.company.nullable.company,mnm.User.company.nullable.mnm.Company,mnm.User.company.nullable,user.company.nullable.mnm.User.company,user.company.nullable.company,user.company.nullable.mnm.Company,user.company.nullable,nullable.mnm.User.company,nullable.company,nullable.mnm.Company,nullable]; arguments [company,class mnm.User]; default message [Property [{0}] of class [{1}] cannot be null]
grails.validation.ValidationException: Validation Error(s) occurred during save():
- Field error in object 'mnm.User' on field 'company': rejected value [null]; codes [mnm.User.company.nullable.error.mnm.User.company,mnm.User.company.nullable.error.company,mnm.User.company.nullable.error.mnm.Company,mnm.User.company.nullable.error,user.company.nullable.error.mnm.User.company,user.company.nullable.error.company,user.company.nullable.error.mnm.Company,user.company.nullable.error,mnm.User.company.nullable.mnm.User.company,mnm.User.company.nullable.company,mnm.User.company.nullable.mnm.Company,mnm.User.company.nullable,user.company.nullable.mnm.User.company,user.company.nullable.company,user.company.nullable.mnm.Company,user.company.nullable,nullable.mnm.User.company,nullable.company,nullable.mnm.Company,nullable]; arguments [company,class mnm.User]; default message [Property [{0}] of class [{1}] cannot be null]

    at mnm.UserIntegrationTests.testSaveUser(UserIntegrationTests.groovy:18)

Even though the both Scenario 1 and Scenario 2 are same, why does the Scenario 2 forces me to add the company(nullable:true) constraint?

(Note that I’m using Grails 1.3.7 and ran the two Scenarios in the same version!.)

Thanks in advance.

Answer 1

If something belongsTo something else, by default it cannot be null

In your test, you do not (still) set a company for the user before you save it, so it will fail with the default constraint