sails.js -postgresql returning string value instead of integer for bigint fields

Question

We are migrating a project from PHP to Node.js using Sails.js as the backend framework. We cannot modify our database and have to use the existing database for this project.

If I keep the migrate: "alter" for a newly created model, Sails by default will keep the id field as an integer.

However, for our existing database, id fields are mostly bigint. So I defined migrate: "safe" and proceeded with the model creation.

Now the problem I am facing is that when blueprint routes return the result, the id column value, which should be returned as a number, is being returned as a string instead. Here is an example:

[
  {
    "starttime": "07:00:00",
    "endtime": "14:00:00",
    "id": "1"
  },
  {
    "starttime": "14:00:00",
    "endtime": "22:00:00",
    "id": "2"
  },
  {
    "starttime": "22:00:00",
    "endtime": "07:00:00",
    "id": "3"
  }
]

How can I fix this issue?

Here is my model:

module.exports = {
  tableName: "timeslots",
  autoCreatedAt: false,
  autoUpdatedAt: false,
  attributes: {
    starttime: { type: "string", required: true },
    endtime: { type: "string", required: true }
  }
};

And here is the postgresql table definition

                                              Table "public.timeslots"
  Column   |  Type  |                       Modifiers                        | Storage  | Stats target | Description 
-----------+--------+--------------------------------------------------------+----------+--------------+-------------
 id        | bigint | not null default nextval('timeslots_id_seq'::regclass) | plain    |              | 
 starttime | text   | not null                                               | extended |              | 
 endtime   | text   | not null                                               | extended |              | 
Indexes:
    "idx_43504_primary" PRIMARY KEY, btree (id)
Referenced by:
    TABLE "doctortimeslot" CONSTRAINT "doctortimeslot_ibfk_2" FOREIGN KEY (timeslot_id) REFERENCES timeslots(id) ON UPDATE CASCADE ON DELETE CASCADE

Answer 1

Waterline gets weird with datatypes it doesn't have built in. I think it defaults to strings when it's not sure what to do. This shouldn't really matter as JS will automatically coerce these values into numbers on your frontend.

However, if you need it to be a number the simplest solution would probably be to override the toJSON method in the model and have it force that value to an integer.

module.exports = {
  tableName: "timeslots",
  autoCreatedAt: false,
  autoUpdatedAt: false,
  attributes: {
    starttime: { type: "string", required: true },
    endtime: { type: "string", required: true },

    toJSON: function(){
      var obj = this.toObject();
      obj.id = parseInt(obj.id);
      return obj;
    }

  }
};