Grails Many to Many Association Querying

Question

I have a many to many relationship.

class Post {
    String title
    static hasMany = [tags:Tag]
}

class Tag {
    static hasMany = [posts:Post]
}

I would like to get a list of posts for a tag that have some other criteria (like a sort order, partial title match, etc). Do I have to use the grails criteria to achieve this? Or is there some way to do something like this:

Post.findAllByTitleLikeAndTagsContains("partial title", aTag)

score 4 · Accepted Answer · answered Jan 12 '10 at 21:22

4

I don't think dynamic finders will allow you to get into one to many or many to many associations - you have to do a criteria or go the HQL query route. You can only query by one to one association, not by one to many. (see section 5.4.1 Dynamic Finders)

answered Jan 12 '10 at 21:22

Jean Barmash

4,788
1
32
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Yep, dynamic finders only support simple properties - criteria time! – leebutts Jan 12 '10 at 22:21
That's what I thought. I really wish grails had an easy way to do this, but I guess I'll just have to put it in JIRA. – Blacktiger Jan 12 '10 at 23:12

score 0 · Answer 2 · answered Dec 28 '11 at 07:52

0

You can use withCriteria,for example:

Post.withCriteria{
    tags {
        eq 'id',aTag.id
    }
 }

answered Dec 28 '11 at 07:52

Ford Guo

957
9
18

True, but if you read my question you would have noticed that I was asking for a way to do it without using criteria. – Blacktiger Jan 03 '12 at 21:30

Grails Many to Many Association Querying

2 Answers2