在数据库生成中重复更新同一查询

I have generated entities from a (MySQL) database, then created a new (zf2) project with a blank database by running the following statements:

vendor/bin/doctrine-module orm:schema-tool:create
vendor/bin/doctrine-module orm:schema-tool:update --force
vendor/bin/doctrine-module orm:validate-schema

Unfortunately the update statement keeps updating the same statement:

ALTER TABLE rollen CHANGE name name VARCHAR(30) NOT NULL;

and the validation fails. The DB shows the correct column. The Doctrine\DBAL\Schema\Comparator shows a different precision (not yet quite sure what that is supposed to be) of the corresponding column.

Some related questions did not seem to fit or work.

Looking at the corresponding diffColumn function in Doctrine\DBAL\Schema\Comparator, showed me that auto-increment set in the meta-data schema (see following annotation):

@ORM\GeneratedValue(strategy="IDENTITY")

the precision part seems to be part of this strategy (although I still don't understand this, since a auto-increment id is rather an in than decimal, see http://doctrine-orm.readthedocs.org/en/latest/reference/annotations-reference.html#column)