Sails JS Waterline join of multiple models - node.js

Question

Hi i'm trying to join multiple tables with populate method, i googled and couldn't find
efficient way of doing it, i do not want to query db several times to build the result, is it possible to solve it with sails version "~0.10.0-rc7" i'm building quit big project with more then hundred of tables.
var co = {
adapter: 'someMysqlServer',
migrate:'safe',
autoCreatedAt: false,
autoUpdatedAt: false,
autoPK:false,
attributes:{
id:{
type:"int",
primaryKey: true,
autoIncrement: true
},
code:"string",
priority :"int",
co_group_c_id :"int",
timezone_c_id :"int",
lang_c_id :"int",
currency_c_id :"int",
name_used :"string",
name_official :"string",
co_tax_no :"int",
co_vat_no :"int",
co_vat_reg :"int",
co_reg_record :"string",
co_representative :"string",
co_addresses:{
collection: "co_address",
via: "co_user_id"
},
}
};
module.exports = co;
var co_address = {
adapter: 'someMysqlServer',
migrate:'safe',
autoCreatedAt: false,
autoUpdatedAt: false,
autoPK:false,
attributes: {
id:{
type:"int",
primaryKey: true,
autoIncrement: true,
},
address_c_id:"int" ,
address_street_first: "string",
address_street_second: "int",
address_street_third: "int",
address_postalcode: "string",
address_city: "string",
co_user_id: {
model: 'co_user'
},
co_id: {
model: 'co'
},
co_address_opening_hours:{
collection: "co_address_opening_hours",
via: "co_address_id"
},
}
};
module.exports = co_address;
var co_address_opening_hours = {
adapter: 'someMysqlServer',
migrate:'safe',
autoCreatedAt: false,
autoUpdatedAt: false,
autoPK:false,
attributes:{
id:{
type:"int",
primaryKey: true,
autoIncrement: true
},
day_c_id: "int",
time_from: "datetime",
time_to :"datetime",
co_address_id: {
model: 'co_address'
}
}
};
module.exports = co_address_opening_hours;
//controller
get_co:function(req,res){
co.find()
.populate("co_addresses")
.populate("co_address_opening_hours")
.exec(function(e, company) {
if(e) console.log(e);
console.log(company);
res.json(company);
})

Answer 1

In SailsJS 0.10+ you can use model associations to do database joins. You can read more about them here: http://sailsjs.com/documentation/concepts/models-and-orm/associations
Basically you first define an association in your model;
var someModel = {
attributes: {
name: {
type: 'text'
}
}
};
var someOtherModel = {
attributes: {
name: {
type: 'text'
},
associationProp: {
model: 'someModel'
}
}
};
In the code above someOtherModel contains association (relation) to someModel. To do a join query you can use .populate() method. For example retrieve all someOtherModel entities and populate associative properties;
someOtherModel.find().populate('associationProp').exec(...);
For MySQL and PSQL adapters there's also .query() method available where you can write some hand written SQL queries to be executed (this also works in sails <0.10);
Model.query(<sql query>, <optional data>, callback);