How to define unique index on multiple columns in sequelize

I have same issue to applied composite unique constraint to multiple columns but nothing work with Mysql, Sequelize(4.10.2) and NodeJs 8.9.4 finally I fixed through following code.

queryInterface.createTable('actions', {
  id: {
      type: Sequelize.INTEGER,
      primaryKey: true,
      autoIncrement: true
  },
  system_id: {
      type: Sequelize.STRING,
      unique: 'actions_unique',
  },
  rule_id: {
      type: Sequelize.STRING,
      unique: 'actions_unique',
  },
  plan_id: {
      type: Sequelize.INTEGER,
      unique: 'actions_unique',
  }
}, {
  uniqueKeys: {
      actions_unique: {
          fields: ['system_id', 'rule_id', 'plan_id']
      }
  }
});

You can refer to this doc http://docs.sequelizejs.com/en/latest/docs/models-definition/#indexes

You will need to change your definition like shown below and call sync

var Tag = sequelize.define('Tag', {
    id: {
        type: DataTypes.INTEGER(11),
        allowNull: false,
        primaryKey: true,
        autoIncrement: true
    },
    user_id: {
        type: DataTypes.INTEGER(11),
        allowNull: false,
    },
    count: {
        type: DataTypes.INTEGER(11),
        allowNull: true
    },
    name: {
        type: DataTypes.STRING,
        allowNull: true,
    }
},
{
    indexes: [
        {
            unique: true,
            fields: ['user_id', 'count', 'name']
        }
    ]
});