title: Limiting and Aliasing fields returned using Sequelize
body: <p>I have an existing WP database that I am trying utilize to create an API using node and sequelize. I'd like to limit the fields which are returned in the query as WP adds a ton of fields I don't want to display in the API. From what I understood, when I define the model, the fields I used, should be the only ones which are returned. It appears though, that the query created is simply using '*'. Also, the aliasing of the field names, do not seem to be happening either. Below is my model.</p>
  
  <pre><code>module.exports = function(sequelize, DataTypes) {
  var Campground = sequelize.define('Campground', {
      ID: {
          type: DataTypes.INTEGER,
          primaryKey: true
      },
      Name: {
          type: DataTypes.STRING,
          field: 'post_title'
      },
      Description: {
          type: DataTypes.TEXT,
          field: 'post_content'
      }
  }, {
      tableName: 'wp_posts',
      timestamps: false,
      defaultScope: {
          where: {
              post_type: 'campgrounds'
          }
      },
      classMethods: {
          associate: function(models) {
              Campground.hasMany(models.Meta, {
                  as: 'Park_Info',
                  foreignKey: 'post_id'
              })
              Campground.hasOne(models.Locator, {
                  foreignKey: 'post_id'
              })
          }
      }
  })
  
  return Campground
  }
  </code></pre>