为grails中的相同域类创建一对多和多对多

Question

I want to create a domain class as like , One user can post many orders [Bidirectional] and one order can be liked by many users [unidirectional].

I have written a domain class as shown below ,

Class User {

  String userName;

  List orders 

  static hasMany = [Order]
}

Class Order {

    String orderId

    String orderName

       //Indicates this order belongs to only one user
    static belongsTo =[owner : User ]  // Bidirectional

    //Indicates order can be liked by many users
    static hasMany = [likedUser : User]   //Unidirectional
 } 

But I am getting am error saying invalid schema . Any body please help...

This post looks similar to my question but I am not getting , Please help.

Answer 1

First, order is a reserved word in SQL. Since GORM by default creates a table with the same name as your class, you'll need to either rename your class or provide a different name to use when mapping to SQL tables.

For example:

class Order {
    static mapping = {
        table 'user_order'
    }
    // ...
}

Another problem is that Order contains two associations to User . You need to tell GORM which one of these that is the bi-directional association from User to Order . That can be achieved using mappedBy , like this:

class User {
    String userName

    static hasMany = [orders: Order]
    static mappedBy = [orders: 'owner']

}

Hope this helps.