List of Strings in a Grails domain class

Question

I am trying to have a List of String that works in MySql in a Grails domain class.

I have tried the following:

class Catalogue {

List books
String book
static hasMany = [books: book]

}

and

class Catalogue {

List books

}

and

class Catalogue {

String[] books

}

and

class Catalogue {

ArrayList<String> books = new ArrayList<String>()

}

The last three compiles but the entry is not present in MySQL. There is no table, or column to represent this data in MySQL and I have tried populating the array with data. Still nothing.

Any ideas?

Answer 1

You can achieve this by using hasMany. Furthermore you need to define books as a List since without it you would get a simple Set that does not allow any duplicates.

class Catalogue {
    static hasMany = [books: String]
    List books
}

Answer 2

Create a domain Book class:

class Book {
 String title
 String isbn
 ...

String toString(){
  return "${title}" 
 }

}

and modify your Catalogue as

class Catalogue{
  String name
  ....
  static hasMany = [books: Book]
  //etc etc 
}