Grails, MySQL and extended classes - mysql

Question

Here is my abstract class :
package mypackage.commons
abstract class Content {
String name
static constraints = {
name nullable: false, blank: false, size: 1..50
}
}
Here is my class which is extended :
package mypackage.project
import mypackage.commons.Content
class Plane extends Content {
String something;
}
Here is my Bootstrap.groovy file :
package mypackage
import mypackage.commons.Content
import mypackage.project.Plane
class BootStrap {
def init = { servletContext ->
Plane boing1 = new Plane (name: 'Boing', something: 'Hello').save()
Plane boing2 = new Plane (name: 'Boing', something: 'Goodbye').save()
}
def destroy = {
}
}
The problem is when I go on MySQL, when I use SHOW TABLES, I only can see content plane.
Here is the content of SELECT * FROM content;
+----+---------+-------+-------------------------+-----------+
| id | version | name | class | something |
+----+---------+-------+-------------------------+-----------+
| 1 | 0 | Boing | mypackage.project.Plane | Hello |
| 2 | 0 | Boing | mypackage.project.Plane | Goodbye |
+----+---------+-------+-------------------------+-----------+
EDIT
After testing Mike's answer :
package mypackage.commons
abstract class Content {
String name
static constraints = {
name nullable: false, blank: false, size: 1..50
}
static mapping = {
tablePerHierarchy false
}
}
here is the result of SHOW TABLES
+-----------------------+
| Tables_in_my_database |
+-----------------------+
| content |
| plane |
+-----------------------+
Here is the result of SELECT * FROM content :
+----+---------+-------+
| id | version | name |
+----+---------+-------+
| 1 | 0 | Boing |
| 2 | 0 | Boing |
+----+---------+-------+
Here is the result of SELECT * FROM plane :
+----+------------+
| id | something |
+----+------------+
| 1 | Hello |
| 2 | Goodbye |
+----+------------+
END OF EDIT
Expected behaviour :
SHOW TABLES; should show me only the table plane
SELECT * FROM plane should show me this :
+----+---------+-------+------------+
| id | version | name | something |
+----+---------+-------+------------+
| 1 | 0 | Boing | Hello |
| 2 | 0 | Boing | Goodbye |
+----+---------+-------+------------+
How can I obtain the expected result ?
Is it possible ?
Thanks in advance.

Answer 1

You need to tell Grails to use table-per-subclass strategy by telling it not to use table-per-hierarchy like:
package mypackage.commons
abstract class Content {
String name
static constraints = {
name nullable: false, blank: false, size: 1..50
}
static mapping = {
tablePerHierarchy false
}
}

Answer 2

I found an answer, I wonder if it's the best way, but it works.
This topic helps me : https://github.com/grails/grails-data-mapping/issues/1254
Firstly, I understand that if I don't want a class to be mapped by Grails, I have to put this class outside of "Domain" package.
So I moove my Content class into src -> main -> groovy -> common (I created this folder) -> Content.groovy
Here is my Content class :
package common
abstract class Content {
String name
static constraints = {
name nullable: false, blank: false, size: 1..50
}
}
Here is my Plane class :
package mypackage.project
import common.Content
class Plane extends Content {
String something;
}
And here is my Bootstrap.groovy :
package mypackage
import mypackage.project.Plane
class BootStrap {
def init = { servletContext ->
Plane boing1 = new Plane (name: 'Boing', something: 'Hello').save()
Plane boing2 = new Plane (name: 'Boing', something: 'Goodbye').save()
}
def destroy = {
}
}
So I avoid tablePerHierarchy use.
In the topic, thay talked about #MappedSupperclass, I don't know what it refers to. I did not use it.
Expected behaviour is reach.
Is it the correct way to do it ?