I use grails-1.3.2 and hbase plugin.
I have some difficulty in creating one-to-Many association with
hbase (i can work with hibernate), so
i decided to try create one-to-Many association with using ArrayList.
Here are my domain classes and controllers:
class Contacts {
String con
static constraints = {}
}
class ContactsController {
def create = {
def contact = new Contacts()
contact.con = params.con
contact.save(flush:true)
}
}
class User {
String firstname
String lastname
// static hasMany = [contact: Contacts]
static ArrayList<Contacts> contact
static constraints = {}
}
class UserController{
def create = {
def user = new User()
user.properties = params
user.save(flush: true)
}
def addContact = {
def user = User.get(params.userID)
def contact = Contacts.get(params.contactID)
user.contact.add(contact)
user.save(flush:true)
}
}
In addContact action user.contact = null, so it can not work.
In user does nor appear contact field.
Can someone help me understand what i have to do for saving ArrayList in db?
I don't know anything about hbase, but the static contact property of the User class looks very suspicious. The fact that this property is static, implies that every user has the same contact list, which seems unlikely to be the desired behaviour.
In a standard GORM domain model - assuming you want each User to have their own contact list - this would be defined
class User {
String firstname
String lastname
static hasMany = [contact: Contacts]
}
Although it looks like we're also defining a static property here, it's actually just the definition of how the Contact and User classes are related (AKA mapping) that is static. The contact property that is dynamically added to the User class is non-static.
Aside
I recommend renaming the Contacts class to Contact and the contact property to contacts. The GORM mapping would then look like this:
class User {
String firstname
String lastname
static hasMany = [contacts: Contact]
}
Related
I'm new to Grails. I'm having problem with retrieving data from DB. I have domains with classes, something like...
class Lightbox {
String name = ''
String link = ''
static hasMany = [users: LightboxUserAccount]
}
class LightboxUserAccount {
UserAccount userAccount
static belongsTo = [lightbox: Lightbox]
}
class UserAccount {
String username
...
}
I want to list all "Lightboxes" owned by user with ID=4. I was trying
def my_lb = Lightbox.findAll("from Lightbox as lb where lb.users=:userAccount", [userAccount: springSecurityService.getCurrentUser()])
or
def my_lb = Lightbox.findAllByUsers(4)
None of those work for me. What am I doing wrong? Thx
Try this one:
Lightbox.findAll("from Lightbox as lb where :userAccount in (lb.users)", [userAccount: springSecurityService.getCurrentUser()])
So I did it slightly different, using criteria instead. Take a look if interested
static getAllByUserAccount(UserAccount userAccount) {
def criteria = Lightbox.createCriteria()
def my_lb = criteria.list {
users {
eq('userAccount', userAccount)
}
}
return my_lb
}
It seems to be working. Thanks for responses though
I have this domain classes, let's say:
class Person {
String name
Integer age
//car data that needs to be shown and filled in views
//but not persisted in Person class
String model
String color
static afterInsert = {
def car = new Car(model: model, color: color)
car.save()
}
}
class Car {
String model
String color
}
What I need is to show in my Person views (create and edit) the model and color properties that are defined inside Person class but these doesn't have to be persisted with this class. These data, model and color, have to be persisted using the Car domain class maybe using the afterInsert event. In other words, I need to save data from a domain class using the views from another domain class.
Thanks in advance.
You can use transients on properties you want GORM to ignore, for example
class Person {
static transients = ['model', 'color']
String name
Integer age
//car data that needs to be shown and filled in views
//but not persisted in Person class
String model
String color
..
}
Just curious but is there a reason you're not using associations
class Person {
..
static hasMany = [cars: Car]
}
class Car {
..
static belongsTo = [Person]
static hasMany = [drivers: Person]
}
.. or composition
class Person {
Car car
}
or simply data binding with multiple domains
//params passed to controller
/personCarController/save?person.name=John&age=30&car.model=honda&car.color=red
//in your controller
def person = new Person(params.person)
def car = new Car(params.car)
i have the following (simplified) domain classes
class Filter {
String name
static hasMany = [answers:Answer]
static belongsTo = [user:User]
}
class User {
String name
static hasMany = [answers:Answer, filters:Filter]
}
class Answer {
String text
}
Then i add answers to the user which is working perfectly. The problem occurs when i delete 1 answer of a user:
def delete = {
def answer = Answer.get(params.id)
def users = User.withCriteria() {
answers{
eq("id", answer.id)
}
}
for (user in users)
user.removeFromAnswers(answer)
answer.delete(flush:true)
redirect(action:"index")
}
What happens here is that ALL user --> answer associations get deleted.
I only want to delete this 1 answer and of cause all associations the answer is used.
I know this has to do with the missing belongsTo, but i can't use it because a ansswer can either belong to a user or to an filter...
You can add the belongsTo to set them to nullable:
class Answer {
String text
static belongsTo = [user:User, filter:Filter]
static constraints = {
user nullable:true
filter nullable:true
}
}
and then just delete the Answer directly in the Controller:
def delete = {
def answer = Answer.get(params.id)
answer.delete(flush:true)
}
GORM will take care of the rest the cascading for you.
I'm a newbie in grails. i'm having a problem right now in my domain classes. I have 3 domain classes, class Patient,class Nurse and class NursePatient, the class NursePatient is a composite key where you can see who is the attending Nurse in a Patient, so if you view its table you can only see the id's of nurses and patients. This is my code for Nurse class:
class Nurse {
String name
Nurse partner
boolean idle = true
static belongsTo = [hospital: Hospital]
static constraints = {
name(blank:false)
partner(nullable:true)
hospital(nullable:false)
}
String toString(){
"Nurse ${name}"
}
}
--> and this is my domain class for NursePatient:
class NursePatient implements Serializable{
Nurse nurse
Patient patient
static mapping = {
version false
id composite:['nurse', 'patient']
}
static constraints = {
patient(nullable:false, validator:{val, obj -> val.hospital == obj.nurse.hospital})
nurse(nullable:false)
}
String toString(){
"Nurse ${nurse.name} - ${patient.name}"
}
void saveIt(Nurse x, Patient y){
def np = new NursePatient(nurse: x, patient: y)
if(np.save()){
def n = nurse.get(nurse.id)
n.idle = false
}
}
}
--> I was asked to print a list of nurses who doesn't have a patient. I was thinking that the moment I save in table using the saveIt() method from class NursePatient, once the save() is successful it changes the value of the property idle of class Nurse from true to false so that querying is much more easier. My problem is I don't if my code in class NursePatient is correct or is it possible to change the value of a property from another class. Please Help me.. thank You!!
Changing properties of domain classes inside different classes is fine.
However, you don't really need a NursePatient class. If you declare the relationship between Nurses and Patients as many-to-many, like this:
class Nurse {
static hasMany = [patients: Patient]
...
}
class Patient {
static hasMany = [nurses: Nurse]
...
}
then Grails will create and update the needed join table automatically. You can then query for all the nurses without patients using Criteria API:
def nursesWithoutPatients = Nurse.withCriteria { isEmpty("patients") }
I have the following classes:
class Employer {
static hasMany = [employees: Employee]
}
class Employee {
String name
static belongsTo = [employer: Employer]
}
I try to save some JSON from the front end (the actual code is a bit more dynamic):
params = {
employer: 1,
name: 'Test'
}
def save = {
def employee = new Employee()
employee.properties = params;
employee.save()
}
However, the save fails because the employer cannot be set from the id. (Failed to convert property value of type 'java.lang.Integer' to required type 'Employer') Is there a way to make that work?
The structure of your JSON is incorrect. It would need to be something more like:
'employer':{
'class':'Employer','id':1
}