如何根据Doctrine2中表中的另一个字段更新字段？

I have table with two columns: price and constant.

I would like to run update on all entries in table to update price based on constant * coefficient.

How could I do such query?

You can do that with a DQL query:

$em->createQuery('
    UPDATE entityClass e
    SET e.price = e.constant * 33;
');

You can also do that with raw SQL:

$em->getConnection()->executeUpdate('
    UPDATE entity_table_name AS e
    SET e.price = e.constant * 33;
');

You could also add a listener on the preUpdate & prePersist doctrine event, so that these values are updated automatically.

See http://docs.doctrine-project.org/projects/doctrine-orm/en/latest/reference/events.html#preupdate for an example.

So that each time you save your entity, it will update the related field automatically.