Sequelize decimal type error

Sequelize is probably the most popular ORM for Express. It helped me to quickly start with a NodeJS server and a Postgres database in my current side project. Unfortunately I encountered a strange issue when I wanted to introduce decimal numbers to one of my models.

Sequelize in version 5.21.3 has an error with decimal type.

My model looked like this:

module.exports = (sequelize, DataTypes) => {
  const incomeExpense = sequelize.define(
    'incomeExpense',
    {
      id: {
        type: DataTypes.INTEGER,
        primaryKey: true,
        autoIncrement: true
      },
      value: DataTypes.DECIMAL(10, 2),
      description: DataTypes.STRING,
      date: DataTypes.DATEONLY,
      type: DataTypes.STRING
    },
    { freezeTableName: true }
  );
  incomeExpense.associate = function(db) {
    incomeExpense.belongsTo(db.stage);
  };
  return incomeExpense;
};

Data in Postgres:

id value description date type stageId
6 120.00 invoice 1 2019-11-11 income 3
7 120.33 invoice 2 2019-11-11 income 3

JSON response:

[
    {
        "id": 6,
        "value": "120.00",
        "description": "invoice 1",
        "date": "2019-11-11",
        "type": "income",
        "createdAt": "2019-11-10T23:00:00.000Z",
        "updatedAt": "2019-11-10T23:00:00.000Z",
        "stageId": 3
    },
    {
        "id": 7,
        "value": "120.33",
        "description": "invoice 2",
        "date": "2019-11-11",
        "type": "income",
        "createdAt": "2020-02-06T16:41:36.868Z",
        "updatedAt": "2020-02-06T16:41:36.868Z",
        "stageId": 3
    }
]

The returned value is a string type.

I thought that the conversion from a number to a string heppens somewhere in Node or React. As it turns out, it is the model itself.

Model after changing the value to DataTypes.FLOAT:

module.exports = (sequelize, DataTypes) => {
  const incomeExpense = sequelize.define(
    'incomeExpense',
    {
      id: {
        type: DataTypes.INTEGER,
        primaryKey: true,
        autoIncrement: true
      },
      // value: DataTypes.DECIMAL(10, 2),
      value: DataTypes.FLOAT,
      description: DataTypes.STRING,
      date: DataTypes.DATEONLY,
      type: DataTypes.STRING
    },
    { freezeTableName: true }
  );
  incomeExpense.associate = function(db) {
    // associations can be defined here
    incomeExpense.belongsTo(db.stage);
  };
  return incomeExpense;
};

Postgres dropped the trailing zeros:

id value description date type stageId
6 120 invoice 1 2019-11-11 income 3
7 120.33 invoice 2 2019-11-11 income 3

And now the value in response is a number:

[
    {
        "id": 6,
        "value": 120,
        "description": "invoice 1",
        "date": "2019-11-11",
        "type": "income",
        "createdAt": "2019-11-10T23:00:00.000Z",
        "updatedAt": "2019-11-10T23:00:00.000Z",
        "stageId": 3
    },
    {
        "id": 7,
        "value": 120.33,
        "description": "invoice 2",
        "date": "2019-11-11",
        "type": "income",
        "createdAt": "2020-02-06T16:41:36.868Z",
        "updatedAt": "2020-02-06T16:41:36.868Z",
        "stageId": 3
    }
]

This issue is opened, and there is an ongoing discussion: link

For now, I can't think of a better fix than Changing a DECIMAL to a FLOAT.