Question

So I have 2 classes that have a many to many association. When the database gets generated I get 2 join tables: user_link_sections and link_section_users. The first I expected, but am not sure why the 2nd join table was generated. Grails is only using the first as well. I’m a noobie to groovy/grails, but tried following the documentation to set this up right. Any help is appreciated!

Here are my domain class declarations…

class User {

    transient springSecurityService

    // Custom Attributes
    String firstName
    String lastName
    String email
    String company
    String phone
    Date dateCreated
    Date lastUpdated

    static hasMany = [linkSections: LinkSection]

    String username
    String password
    boolean enabled
    boolean accountExpired
    boolean accountLocked
    boolean passwordExpired
}

and

class LinkSection {

    String name
    String description
    Date dateCreated
    Date lastUpdated

    List links = new ArrayList()

    static belongsTo = User
    static hasMany = [links: Link, users: User]

    static constraints = {
    name blank: false
    description(maxSize: 10000)
    }

    static mapping = {
    links cascade: "all,delete-orphan"
    }
}

Answer 1

Try setting the owning side of the many-many:

static belongsTo = User

this goes on the LinkSection. Remember only one side knows to persist the relationship.

The other thing to do is to make sure and clear out the tables that may have been left over from your previous attempts at mapping…just to be sure.