neumino
Can I reuse hasAndBelongsToMany relationship with same Model?
I want to use User_User_following table to handle user.followings and user.followers.
const User = thinky.createModel('User', {
id: type.string(),
});
User.hasAndBelongsToMany(User, 'followings', 'id', 'id', {
type: 'followings',
});
User.hasAndBelongsToMany(User, 'followers', 'id', 'id', {
type: 'followers',
});
This implementation create different two relationship. I need to use one relationhip and reuse that.
const User = thinky.createModel('User', {
id: type.string(),
});
User.hasAndBelongsToMany(User, 'followings', 'id', 'id', {
backref: 'followers', // I need this part!
});
Like this.
From now on, Creating relation with same model several time is available by options.type.
But reuse hasAndBelongsToMany relationship is unable. (I think)
Can I reuse hasAndBelongsToMany relation?
You can use type in the options
http://thinky.io/documentation/api/model/#hasandbelongstomany
But type option create 'different' relationship. What I need is use same relationship table.
Oh, what you want is non bidirectional n-n relations. Thinky currently doesn't support that. I think you have to sneak another table for now and use 2 hasAndBelongsToMany. Being able to save custom fields in the relation could solve your problem too, but it's not yet available.
const User = thinky.createModel('User', {
id: type.string(),
});
User.hasAndBelongsToMany(User, 'followings', 'id', 'id', {
type: 'followings',
});
User.hasAndBelongsToMany(User, 'followers', 'id', 'id', {
type: 'followers',
});
User.define('follow', function(targetUser) {
return Promise.all([
this.addRelation('followings', { id: targetUser.id }).run(),
targetUser.addRelation('followers', { id: this.id }).run(),
]);
});
User.define('unfollow', function(targetUser) {
return Promise.all([
this.removeRelation('followings', { id: targetUser.id }).run(),
targetUser.removeRelation('followers', { id: this.id }).run(),
]);
});
From now on, I think this pattern can temporary solve that problem. :D Thank you!
How you get only the 'followings'?
User.get('a user id').getJoin({ followings: true }).execute() //return b in "followings"
User.get('b user id').getJoin({ followings: true }).execute() //return a in "followings"
I need to get this result:
User.get('a user id').getJoin({ followings: true }).execute() //return b in "followings"
User.get('b user id').getJoin({ followings: true }).execute() //return empty "followings"
@SagiUziel I had same problem about that.
Thinky is really good library and handle so many things. But In that case, I can't find a way to handle that issue.
So I just create new library for rethinkdb and use that. In nothinkdb, Handling n-m relation by explicitly defined relationship table.
If you interested in how nothinkdb solve that problem, refer this