Object relational mapping in Grails - grails

Question

I have 2 tables named 'employees' and 'dataentry'. I need to set the employee_id column in employees table as primary key, and also employee_id column in dataentry as a foreign key of employees.employee_id. How can I do this in groovy domain class.
here is my employees.groovy model class
package com.standout.utilityapplication
import java.util.Date;
import com.standout.utilityapplication.Dataentry
class Employees {
static mapping = {
table 'employees'
version false
}
static hasMany = [employee_id:Dataentry]
String employee_id
String employee_name
String team
Long contact_no
String designation
static constraints = {
employee_id(nullable: false,maxSize:10)
employee_name(nullable: false,maxSize:100)
team(nullable: true,maxSize:40)
contact_no(nullable: true,maxSize:10)
designation(nullable: true,maxSize:40)
}
}
and here is my dataentry.groovy model class
package com.standout.utilityapplication
import com.standout.utilityapplication.Employees
class Dataentry {
static mapping = {
table 'dataentry'
version false
}
static belongsTo = [employee_id:Employees]
String employee_id
String team
Date receipt_dt
String restaurant_name
int number_of_persons
float amount
Date bill_submitted_dt
String reimbursed
char presented_bank_fl
Date presented_bank_dt
String create_id
Date create_dt
String mod_id
Date mod_dt
static constraints = {
reimbursed(nullable: true)
presented_bank_fl(nullable: true)
presented_bank_dt(nullable: true)
mod_id(nullable: true)
mod_dt(nullable: true)
}
}
Please tell me how to make a mapping with cascaded

Answer 1

Something akin to this should get the entities joined. Convention is to name an entity in the singular, not a plural (Employee, not Employees):
class Employee {
static hasMany = [dataentries:Dataentry]
static mapping = {
id name:'employee_id'
}
}
class Dataentry {
static belongsTo = [employee:Employee]
}
Let the system take care of the details.