How to use CASE WHEN expression in Sequelize?

Question

Using Sequelize ORM for Node.js, how do you use CASE/WHEN expression in a select statement?

I do not see any reference or examples to use the SQL expression CASE acc

Answer 1

You can use Sequelize.literal in attributes to build special queries

var query = {
  attributes: [
    'userId',
    [Sequelize.literal(`MAX(CASE Type WHEN 'Employee' THEN Rate ELSE 0 END)`), 'Employee'],
    [Sequelize.literal(`MAX(CASE Type WHEN 'School' THEN Rate ELSE 0 END)`), 'School'],
    [Sequelize.literal(`MAX(CASE Type WHEN 'Public' THEN Rate ELSE 0 END)`), 'Public'],
    [Sequelize.literal(`MAX(CASE Type WHEN 'Other' THEN Rate ELSE 0 END)`), 'Other'],
  ],
  where: {
    user: userId,
    Type: ['Employee', 'School', 'Public', 'Other'],
  },
  group: ['userId'],
  raw: true
};
models.invoice.findAll(query).then(result => {
  console.log(result);
});