Belajar Express JS | Sequelize Validation

When working with Express JS and Sequelize, it is important to validate the request body before performing any operations on the database. In this article, we will discuss how to implement validation for a POST method using Sequelize.

Sequelize Validation

Sequelize provides built-in validation options that can be used to validate the incoming data before saving it to the database. This helps in maintaining data integrity and preventing any invalid data from being inserted into the database.

To implement validation using Sequelize, we need to define a Sequelize model with the required validation rules. For example, if we have a ‘User’ model with properties like ‘name’, ’email’, and ‘age’, we can define validation rules for each property like this:

const User = Sequelize.define('User', {
  name: {
    type: Sequelize.STRING,
    allowNull: false,
    validate: {
      notEmpty: true
    }
  },
  email: {
    type: Sequelize.STRING,
    allowNull: false,
    validate: {
      isEmail: true
    }
  },
  age: {
    type: Sequelize.INTEGER,
    allowNull: false,
    validate: {
      isInt: true
    }
  }
});
  

Request Body POST Method

When handling a POST method in Express JS, we can access the incoming data from the request body. To validate this data using Sequelize, we can use the ‘create’ method of the model and pass the request body as the argument. Sequelize will automatically apply the validation rules defined in the model.

app.post('/users', async (req, res) => {
  try {
    const user = await User.create(req.body);
    res.json(user);
  } catch (error) {
    res.status(400).json({ error: error.message });
  }
});
  

Conclusion

In this article, we have learned how to implement validation for a POST method using Sequelize in Express JS. By defining validation rules in the model and using the ‘create’ method, we can ensure that only valid data is inserted into the database. This helps in maintaining data consistency and prevents data corruption.