Grails GORM find by value inside map of Domain - grails

Question

I am using Grails 2.2.4 and having one Domain contains value as map and I want to find domain object using key of map. Please help me to resolve this issue.
Student.groovy
package com.grails
import java.util.Map;
class Student {
String firstName
String lastName
Map address
static constraints = {
}
}
When My application are run I can see that Grails application create tables in database are as follow:
1) first table
student
id
version
first_name
last_name
indexes
2) second table
student_address
address
addres_idx
addres_elt
When I save Domain as:
def std = new Student()
std.firstName = 'Piyush'
std.lastName = 'Chaudhari'
std.address = [city:'Surat',state:'Gujarat',pincode:'38001']
std.save(flash:true)
values are insert in database as follow:
student table
ID VERSION FIRST_NAME LAST_NAME
1 0 Piyush Chaudhari
student_address table
ADDRESS ADDRESS_IDX ADDRESS_ELT
1 city Surat
1 state Gujarat
1 pincode 38001
Now, I want data or row using GORM like Student.findBy_____ or Student.findAllBy______
where 'city' = surat
Any one can help me to resolved this issue?

Answer 1

You can use:
Student.findBy<FieldName1>And<FieldName2> (<FieldNameParameter1>, <FieldNameParameter2>)
Or Either:`
Student.list().find { it.address.city == 'Surat' }
Student.list().findAll { it.address.city == 'Surat' }
`

Answer 2

I don't think that you can search things like this using maps.
Maybe you can do this:
def students = Student.list()
def result = students.each { student -> student.address.city == 'Surat' }
println("Resultado" + result)
But this is a very bad way to do this kind of things

Answer 3

Define an address class, and then add an address field to the student class (this will change how your tables are mapped in the database):
class Student {
String firstName
String lastName
Address address
static constraints = {
}
}
class Address {
String city
String state
String pincode
}
Address should be another entity in your domain, not a map of values. Remember that Grails GROM is an ORM, so you should design your domain using a OOP model in order to take advantage of the dynamic finders and criterias for doing queries.
With those changes in place, you can now use a simple criteria:
def students = Student.withCriteria{
'address'{
eq('city', 'surat')
}
}
More information about criterias in the grails docs:
http://grails.org/doc/latest/ref/Domain%20Classes/withCriteria.html
http://grails.org/doc/latest/guide/single.html#criteria
If you want to use Dynamic finders, you will have to get all the address with city = 'surat' and then use a findByAddressInList(...). But i think that in this case, criterias is a better approach