MySQL error when creating field schema
I fixed this problem by myself. Please note the mistyped column type name integer which is now int:

function google_directions_field_schema($field)
{
    return array(
        'columns' =&gt; array(
            'lat' =&gt; array(
                'type' =&gt; 'float',
                'size' =&gt; 'big',
                'not null' =&gt; false,
            ),
            'lng' =&gt; array(
                'type' =&gt; 'float',
                'size' =&gt; 'big',
                'not null' =&gt; false,
            ),
            'mapTypeId' =&gt; array(
                'type' =&gt; 'varchar',
                'length' =&gt; '15',
                'not null' =&gt; false,
            ),
            'zoom' =&gt; array(
                'type' =&gt; 'int',
                'size' =&gt; 'small',
                'not null' =&gt; false,
            ),
        ),
        'indexes' =&gt; array(
            'lat_lng' =&gt; array('lat', 'lng'),
        ),
    );
}