Sails.js associations - mysql

Question

I am beginning with sails.js and I am completely lost with my sql queries.
I have the following tables :
genres
+-----------+--------------+------+-----+
| Field | Type | Null | Key |
+-----------+--------------+------+-----+
| id | int(6) | NO | PRI |
| name | varchar(100) | NO | |
| slug | varchar(255) | NO | |
| type | varchar(32) | NO | |
| parent_id | int(11) | YES | MUL |
+-----------+--------------+------+-----+
genres_radios
+----------+--------+------+-----+
| Field | Type | Null | Key |
+----------+--------+------+-----+
| genre_id | int(6) | NO | MUL |
| radio_id | int(6) | NO | MUL |
+----------+--------+------+-----+
radios
+-----------+--------------+------+-----+
| Field | Type | Null | Key |
+-----------+--------------+------+-----+
| id | int(5) | NO | PRI |
| name | varchar(100) | NO | |
| slug | varchar(100) | NO | |
| url | varchar(100) | NO | |
+-----------+--------------+------+-----+
I want to retrieve the radios and their associated genres. I managed to do it using the Model.query("Select * FROM ...") but I'd like to do it using the populate method. I had a look at the docs, but I am a bit confused with the "via", "through", ...

Answer 1

Well if you've followed the Sails.js Model documentation and the many-many association docs your models should look something like:
// api/models/genre.js
module.exports = {
attributes : {
name : {
type: 'string'
},
slug : {
type: 'string'
},
type : {
type: 'string'
},
radios : {
collection: 'radio',
via: 'genres'
}
}
}
// api/models/radio.js
module.exports = {
attributes : {
name : {
type: 'string'
},
slug : {
type: 'string'
},
url : {
type: 'string'
},
genres : {
collection: 'genre',
via: 'radios'
}
}
}
The many-many lookup table will be created for you internally by waterline. All you need to get the genres for your radio is populate the "genres" attribute.
Radio.findOne({name:"RadioName"}).populate("genres").then(function(radio){
console.log(radio); //radio.genres will have all the genres associated with this radio.
})
I really do recommend looking at the many-many association docs. They have exactly what you need.

Answer 2

This should do it :
// api/models/Genres.js
module.exports = {
attributes : {
name : {
type: 'string'
},
slug : {
type: 'string'
},
type : {
type: 'string'
},
radios : {
collection: 'Radios',
through: 'genres_radios'
}
}
}
// api/models/Radios.js
module.exports = {
attributes : {
name : {
type: 'string'
},
slug : {
type: 'string'
},
url : {
type: 'string'
},
genres : {
collection: 'genre',
through: 'genres_radios'
}
}
}
// api/models/Genres_radios.js
module.exports = {
attributes = {
'Genre_id': {
columnName:'genre_id',
type:'integer',
foreignKey:'true',
references:'genres',
on:'id',
via:'genres'
},
'Radio_id': {
columnName:'radio_id',
type:'integer',
foreignKey:'true',
references:'radios',
on:'id',
via:'radios'
}
}
}
And then you can make the following request :
Radio.findOne({name:"RadioName"}).populate("genres").then(function(radio){
console.log(radio);
})