根据grails中的父属性对查询结果进行排序 [英] Sorting query results according to parent property in grails

问题描述

grails中是否有可能根据关系中父类的属性对查询结果进行排序。例如。我有一个与任务列表有一对多关系的用户域类。

Is it possible in grails to sort query results according to a property of a parent class in a relationship. E.g. I have a user domain class which has a one to many relationship with a list of Tasks.

当显示Tasks域类的列表页面时，我希望能够

When showing the list page of the Tasks domain class, I want to be able to sort the list of tasks by the associated User name.

class User {
    String name
    String login
    String group
    List tasks = new ArrayList()
    static hasMany = [tasks:Task]
}

class Task {
    String summary
    String details
    User user
    static belongsTo = [user:User]
}

我可以这样做

I can do something like this

Task.list([sort:"user", order:"asc"])

但是这样的user.id，有没有办法指定排序在user.name？

But this sorts by the user.id, is there a way to specify the sort to be on the user.name?

推荐答案

您可以使用 Criteria

def criteria = Task.createCriteria()
def taskList = criteria.list {
    createAlias("user","_user")
    order( "_user.name")
}

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