Defining default sort-order in Grails/GORM

Question

Let's say I have definied a User object using GORM. Each user can have zero or more Login:s. Each Login has a timestamp. When retrieving user.logins I want the logins to be sorted based on the value of login.date. What is the correct Grails way to achieve this?

Example: I want the following code to list all the user's logins in ascending order.

<g:each var="login" in="${user.logins}">
  <tr>
    <td>${login.date}</td>
  </tr>
</g:each>

These are the referenced classes:

class User {
  ...
  def hasMany = [logins: Login]
  static fetchMode = [logins: "eager"]
}

class Login {
  Date date
  ...
  def belongsTo = [User]
}

I'm running Grails 1.0.4 which is the latest stable release.

score 30 · Answer 1 · edited Nov 18 '11 at 13:30

30

They show how to do this on the GORM page in the reference guide (section 5). The bit you want is near the bottom of that document is the section you want. They have two simple examples:

class Airport {
    …
    static mapping = {
        sort "name"
    }
}

class Airport {
    …
    static mapping = {
        sort name:"desc"
    }
}

They also have an example of sorting on an association:

class Airport {
    …
    static hasMany = [flights:Flight]
    static mapping = {
        flights sort:'number'
    }
}

edited Nov 18 '11 at 13:30

Jason Plank

2,336
5
31
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answered May 27 '09 at 22:31

2

And if you want descending on association: `flights sort:'number', order: 'desc'` (per http://grails.1312388.n4.nabble.com/sort-by-association-descending-td1312425.html) – Jeff Allen Apr 16 '13 at 01:27
1

How can I sort multiple attributes? – ricardogobbo Dec 08 '15 at 17:42
1

@ricardogobbo Might be a tad late, but here you go: `static mapping = { sort([column1: 'asc', column2: 'asc']) }` – Gideon Jul 05 '18 at 07:46

score 14 · Answer 2 · edited Sep 03 '13 at 18:19

Just make the Login Class implement the Comparable interface:

class Login implements Comparable {

    // ...

    Date date

    public int compareTo(def other) {
        return date <=> other?.date // <=> is the compareTo operator in groovy
    }

}

and declare the relation to be a SortedSet:

class User {
  ...
  def hasMany = [logins: Login]               
  SortedSet logins

  static fetchMode = [logins: "eager"]
}

score 8 · Accepted Answer · answered Mar 10 '09 at 18:23

8

The handling of default sort order in Grails/GORM seems to have been radically simplified in Grails 1.1:

Grails 1.1 release notes (search for "Default Sort Order")

answered Mar 10 '09 at 18:23

knorv

49,059
74
210
294

Defining default sort-order in Grails/GORM

3 Answers3

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