title: Migration - Cannot Change Double Data Type Value
body: <p>I have an existing table created with this migration code:</p>
  
  <pre><code>Schema::create('mytable', function (Blueprint $table) {
  
   $table-&gt;increments('id');
   $table-&gt;double('mycolumn',8,2)-&gt;unsigned()-&gt;default(0);
   $table-&gt;timestamps();
  
  });
  </code></pre>
  
  <p>Then I have created another migration file to adjust the value range of my <code>mycolumn</code> field with the migration file below.</p>
  
  <pre><code>Schema::table('mytable', function (Blueprint $table) {
  
   $table-&gt;double('mycolumn',15,2)-&gt;unsigned()-&gt;default(0)-&gt;change();
  
  });
  </code></pre>
  
  <p>However I am getting an error:</p>
  
  <pre><code>In DBALException.php line 283:
  
    Unknown column type "double" requested. Any Doctrine type that you use has to be registered with \Doctrine\DBAL\Types\Type::addType(). You can get a li
    st of all the known types with \Doctrine\DBAL\Types\Type::getTypesMap(). If this error occurs during database introspection then you might have forgott
    en to register all database types for a Doctrine Type. Use AbstractPlatform#registerDoctrineTypeMapping() or have your custom types implement Type#getM
    appedDatabaseTypes(). If the type name is empty you might have a problem with the cache or forgot some mapping information.
  </code></pre>
  
  <p>What am I missing?</p>