Ordering by the COUNT of a relation

Issue type:

[x] question [ ] bug report [ ] feature request [ ] documentation issue

Database system/driver:

[ ] cordova [ ] mongodb [ ] mssql [x] mysql / mariadb [ ] oracle [ ] postgres [ ] cockroachdb [ ] sqlite [ ] sqljs [ ] react-native [ ] expo

TypeORM version:

[x] latest [ ] @next [ ] 0.x.x (or put your version here)

Steps to reproduce or a small repository showing the problem:

I’m a bit confused by how to order my data by the COUNT of a relation. If I have a post with likes:

@Entity()
class Post {
  @OneToMany('PlaceLike', 'place', { cascade: true, eager: true })
  likes: PlaceLike[]
}

How do I ORDER BY the number of Likes a Post has? There seems to be a few undocumented/deprecated ways like @RelationCount and loadRelationCountAndMap but they don’t really work. Any ideas?

[pincman]

@sekaru just

this.createQueryBuilder('a')
                .select('a.id')
                .addSelect((subQuery) => {
                    return subQuery
                        .select('COUNT(c.id)', 'count')
                        .from(Comment, 'c')
                        .where('c.article.id = a.id');
                }, 'count')
                .orderBy('count', 'DESC')
                .loadRelationCountAndMap('a.comment_count', 'a.comments')

both has orderBy and Count

[aboveyunhai]

@sekaru just

this.createQueryBuilder('a')
                .select('a.id')
                .addSelect((subQuery) => {
                    return subQuery
                        .select('COUNT(c.id)', 'count')
                        .from(Comment, 'c')
                        .where('c.article.id = a.id');
                }, 'count')
                .orderBy('count', 'DESC')
                .loadRelationCountAndMap('a.comment_count', 'a.comments')

both has orderBy and Count

wouldn’t this cause querying Comment twice unnecessarily ? one from addSelect and one from load relation? I felt like it may cause performance issue. Correct me if I’m wrong.

Also it seems like there is a terrible bug with typeORM for postgresql .orderBy('count', 'DESC') may cause column does not exist, instead use

.orderBy(`"count"`, 'DESC)`  OR .orderBy('"count"', 'DESC')

It’s extremely frustrating after I check the raw query.