I have domain
Training
class Training {
static belongsTo = [venue: Venue]
}
Venue
class Venue {
static belongsTo = [city: City]
}
City
class City {
String name
}
now i want to sort Training based on City name .
is there a way to do it in Grails (Gorm)way?
have you tried
def results = Training.withCriteria {
order('venue.city.name', 'asc')
}
Training.list().sort{it.venue.city.name}
def results = Training.list(sort:"venue.city.name", order:"asc")
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
My project requires me to maintain the insertion and retrieval order in a many-many relationship. By default, groovy saves the elements as a Set in many-many relationship. I want to do it in a List. I am not sure how to update the relationship to use List instead of Set. Any help would be appreciated.
class Course{
static belongsTo = Teacher
static hasMany = [teacher:Teacher]
static mapping = {
teacher joinTable : [name: TeacherCourse]
}
}
class Teacher{
static hasMany = [course:Course]
static mapping = {
course joinTable : [name: TeacherCourse]
}
}
save() call on either Teacher or Course also inserts a new row in TeacherCourse table. It works with no issues. In Database there the tables are:-
Teacher (PK: Id)
Course (PK: Id)
TeacherCourse(PK: [Teacher_id,Course_id])
Is there a way I can maintain the order of insertion and retrieval in many-many relationship?
Thank you..
Edit
In controller save()
def courseInstance = new Course()
List <Teacher> teacherList= []
teacherList.add(Teacher.findById(65))
teacherList.add(Teacher.findById(36))
courseInstance.courseUnits = teacherList
courseInstance.save(flush:true)
Try this:
class Course {
List teachers
static belongsTo = Teacher
static hasMany = [teachers:Teacher]
static mapping = {
teachers joinTable : [name: TeacherCourse]
}
}
class Teacher {
List courses
static hasMany = [courses:Course]
static mapping = {
courses joinTable : [name: TeacherCourse]
}
}
Reference
Assuming I have a Person and a Status. If Status is like this :
class Status {
String text
Person author
}
I would have done something like this to get the messages list of the current user :
def messages = Status.withCriteria {
author {
eq 'username', currentPerson.username
}
}
But if my relationship in Status is like this, how can I do so?
static belongsTo = [Person]
Thanks for your help.
I tend to use the map notation for belongsTo, so I would do it like this:
class Status {
String text
static belongsTo = [author: Person]
}
Then you're query is easy:
def messages = Status.findAllByAuthor(currentPerson)
If you had bidirectional added into Person with hasMany:
class Person {
static hasMany = [messages: Status]
}
You could also do this:
def messages = currentPerson.messages
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") }