title: Sequelize Foreign key: snake_case in DB and CamelCase in code. Does it possible?
body: <p>I use <strong>snake_case</strong> <strong>in</strong> my MySql <strong>DB</strong>. And I use <strong>CamelCase</strong> <strong>in</strong> my <strong>JS code.</strong> 
  So my code looks like:</p>
  
  <pre><code>sequelize.define('User', {
          'UserId': {
              field: 'user_id',
          },
          'UserName': {
              field: 'user_name',
          },
  </code></pre>
  
  <p>I created foreign key:</p>
  
  <pre><code> classMethods: {
      associate: function (models) {
          User.belongsTo(models.UserRole, {
              foreignKey: {
                  name: 'user_role_id',
              }
          });
      }
  }
  </code></pre>
  
  <p>Does sequelize able to use <code>user_role_id</code> in DB and <code>UserRoleId</code> in JS code? </p>
  
  <p>Thanks!</p>