Wrong diff between Oracle 'Date' type and Metadata 'Date' type

Hi,
I want to update my schema but I am getting the following error message:

[Doctrine\DBAL\Driver\OCI8\OCI8Exception]
ORA-01442: column to be modified to NOT NULL is already NOT NULL

--dump-sql says:

ALTER TABLE CONSIGNMENTS MODIFY (SDGDATE  DATE DEFAULT NULL);

The current table structure looks like that:

Mapping definition:

/**
 * @ORM\Column(name="SDGDATE",type="date",nullable=true)
 */
private $sdgdate;

I think there is a problem with the comparison between Oracles 'Date' type and the Metadata 'Date' type. I am used to use MySQL as DBMS but our customer uses Oracle. MySQL's 'datetime' and Oracle's 'date' type are store the same data.

I am not sure what should be done here. Because this could lead to confusion for all Oracle user.

Maybe there could be a request to the platform in the Schema Comparator here:

public function diffColumn(Column $column1, Column $column2)
{
    $changedProperties = array();
    if ( $column1->getType() != $column2->getType() ) {
        $changedProperties[] = 'type';
    }
    // ...
}