CODEWITHSUNDEEP
javascriptnode.jspostgresqlsequelize.js
PIKP
PIKP

Reputation: 843

How to add a custom DataType in Sequelize ORM

I want to define a custom data type in Sequelize by inheriting all default behaviours of existing DataType.Integer. The base idea here is to define a new type and override valueOf and toString methods.

The Sequelize docs doesn't contain any information related to this topic. It would be really nice if someone can help me on this.

Upvotes: 5

Views: 6075

Answers (3)

Mike
Mike

Reputation: 13

In v6, Sequelize provides a guide, with code examples, on how to do this. It is similar to the solutions already provided, but I thought it should be added here for completeness.

https://sequelize.org/docs/v6/other-topics/extending-data-types/

Upvotes: 1

shtse8
shtse8

Reputation: 1365

To extend DataTypes in Sequelize:

class DataTypes_IP extends DataTypes.ABSTRACT {
  constructor () {
    super()
    this.key = 'IP'
  }

  toSql() {
    return 'VARBINARY(16)'
  }

  // Todo
  validate (value) {
    // const Validator = require('./utils/validator-extras').validator 
    // if (!Validator.isDate(String(value))) {
    //   throw new sequelizeErrors.ValidationError(util.format('%j is not a valid date', value)) 
    // }
    return true 
  }

  _sanitize (value) {
    return new IP(value) 
  } 

  _isChanged (value, originalValue) {

    if (value === originalValue) return false
    if (
      value instanceof IP && 
      originalValue instanceof IP && 
      value.toBuffer().equals(originalValue.toBuffer()) 
      ) {
      return false
    }
    return true
  } 

  _stringify (ip) {
    return ip.toBuffer() 
  } 
}

And extends the DataTypes

DataTypes.IP = DataTypes_IP

You can check the relevant issue in github. https://github.com/sequelize/sequelize/issues/8533

Upvotes: 0

Evan Lucas
Evan Lucas

Reputation: 632

https://github.com/sequelize/sequelize/blob/master/lib/data-types.js holds the sequelize data types.

Specifically, https://github.com/sequelize/sequelize/blob/master/lib/data-types.js#L251-L273 shows how DataTypes.INTEGER inherits from DataTypes.NUMBER using NUMBER.inherits(fn).

Those inherit from ABSTRACT. You could override the toString() method for your inherited data type like as seen at https://github.com/sequelize/sequelize/blob/master/lib/data-types.js#L62-L64.

Disclaimer: with it not being publicly documented, I am not sure how stable the APIs are and would be cautious due to possible future changes.

Upvotes: 2

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