Grails hasMany enum with a custom hibernate UserType

Question

I have an enum with a hibernate custom UserType:

enum Program { ABC(1000), XYZ(1001); final long code; ... }

class ProgramUserType implements org.hibernate.usertype.UserType { ... }  

The ProgramUserType stores the code (1000, 1001, etc) for the enum and gets the enum instance back via the code when read from the database.

This is in use successfully on a relationship in a domain class:

class MyDomainOne {
    Program program
    ...
    static mapping = {
        ...
        program column: 'PROGRAM_ID', type: ProgramUserType
        ...
    }
}

So, all of the above works fine.

But I want to use the enum in a hasMany relationship:

class MyDomainTwo {
    ...
    static hasMany = [
        programs: Program
    ]
    ...
    static mapping = {
        ...
        programs joinTable: [name: 'BLAH_DOM_TWO_PROGS', key: 'DOM_TWO_ID', column: 'PROGRAM_ID']
        ...
    }
}

My issue is that always produces a column with a "varchar2(255 char)" type:

BLAH_DOM_TWO_PROGS (DOM_TWO_ID number(19,0) not null, PROGRAM_ID varchar2(255 char));

I've tried various things to no avail:

programs joinTable: [name: 'BLAH_DOM_TWO_PROGS', key: 'DOM_TWO_ID', column: 'PROGRAM_ID', type: ProgramUserType]

programs joinTable: [name: 'BLAH_DOM_TWO_PROGS', key: 'DOM_TWO_ID', column: 'PROGRAM_ID', type: ProgramUserType, sqlType: 'NUMBER(10,0)']

programs type: ProgramUserType, joinTable: [...]

etc.

What is the proper syntax to use a custom user type in a join table mapping?

(I'm using grails 2.3.7)

Answer 1

I don't know why you do this complex but in order to write a code(Integer, Long, String...) into a column of database from an enum, you can implement simply like this:

enum Program {
    ABC(0, "ABC"),
    XYZ(1, "XYZ"),

    final String value
    final Integer id

    Program(Integer value, String selectValue) {
        this.id = value
        this.value = selectValue
    }

    //https://github.com/tudor-malene/Easygrid/issues/22
    //shows value in select drop down
    String toString() { value }

    //stores value in database
    Integer getId() { id }

    //returns Enum constant associated with value
    String getKey(){ name() }
}

The importance line of code is Integer getId() { id } You can change id property to whatever type you want. Hope it help

some reference links GRAILS-3633 or in another discussion