title: Sequelize + mySQL : How to delete item from a field that is an array
body: <p>I have a field in my model that I want to be an array, so I've defined it like this</p>
  <pre><code>names:{
              type : Sequelize.STRING,
              get(){
                  return this.getDataValue('names')
              },
              set(value){
                  return this.setDataValue('names', value)
              },
              default : []
          },}
  </code></pre>
  <p>Now i've found very little info on how to add an item to this array but I wrote this</p>
  <pre><code>    { where: { id: req.body.id } },
  names: Sequelize.fn(
          &quot;array_append&quot;,
          Sequelize.col(&quot;names&quot;),
          userName
        )
      }
  </code></pre>
  <p>is this correct ?
  what if I want to delete an item from this array ? what should be the contrary of array_append ?
  Thanks for answering as the doc on the subject is very poor :)</p>