(Quick Reference)
joinTable
Purpose
Customizes the join table used for undirectional one-to-many, many-to-many and primitive collection types.
Examples
Basic collection type:
class Book {
static hasMany = [chapterPageCounts:Integer] static mapping = {
chapterPageCounts indexColumn:[name:"chapter_number", type:Integer],
joinTable:[column:"page_count"]}Enum collection types:
enum VehicleStatus { OFF, IDLING, ACCELERATING, DECELERATING }class Truck { static hasMany = [states:VehicleStatus] static mapping = {
states joinTable: [name: 'VEHICLE_STATUS_LOG',
key: 'TRUCK_ID', column: 'STATUS']
}
}Many-to-many:
class Book { String title
static belongsTo = Author
static hasMany = [authors:Author] static mapping = {
authors joinTable:[name:"mm_author_books", key:'mm_book_id' ]
}
}
class Author {
String name static hasMany = [books:Book] static mapping = {
books joinTable:[name:"mm_author_books", key:'mm_author_id']
}
}Unidirectional One-to-many:
class Employee {
static hasMany = [projects: Project] static mapping = {
projects joinTable: [name: 'EMP_PROJ',
column: 'PROJECT_ID',
key: 'EMPLOYEE_ID']
}
}class Project { }Description
Usage:
association_name(joinTable:map)Arguments:
name - The table namekey (optional) - The foreign keycolumn (optional) - The inverse column
GORM has various strategies for mapping association types. Some of them, such as basic collection types and many-to-many associations, require the use of a join table. You can customize how this join table is created using the
joinTable argument.
