Grails默认对关联进行排序（双向一对多）

Question

I am trying to default sort an association, my domain classes are as follows

Class Section{
    Integer displayOrder
    static hasMany=[questionCategories:QuestionCategory]

    static mapping={
        questionCategories sort:'displayOrder'
    }
}

Class QuestionCategory{
    Integer displayOrder
    static hasMany=[questions:Question]

    static mapping={
        questions sort:'displayOrder'
    }
}

Class Question{
    Integer displayOrder
}

basically i want to get a list of section objects which is sorted by section class's displayOrder, the inner questionCategories sorted by questionCatgory Class's displayOrder and similarly questions sorted by Question class's displayOrder

I have tried SortedSet approach and that works fine, but unfortunately we cannot use it

with this configuration i am getting this error

java.sql.SQLSyntaxErrorException: ORA-00904: "QUESTIONCA3_"."DISPLAY_ORDER": invalid identifier

Answer 1

This looks like your database is not setup correctly. One of your underlying tables doesn't have a "DISPLAY_ORDER" column. Judging by the "QUESTIONCA3_" I'd guess it's the table related to QuestionCategory.