Types for dbal has to be defined twice about doctrinebundle

[stof]

@mvrhov They are not redundant as these are 2 different things. The first one is about registering a DBAL type, and give the name of the class. Under connection, what is registered is the mapping between a DB type and a doctrine type. This mapping is specific to the DB you use (DB type names are not the same across platforms) and are not a 1-1 mapping to doctrine types. For instance, Doctrine registers many different DB types to the string doctrine type.

So we cannot try to workaround it in ConnectionFactory as it would require guessing things about the DB you use and the meaning of your doctrine types.
Thus, we agreed long ago that DoctrineBundle is about integrating Doctrine with Symfony, not about reimplementing Doctrine in Symfony (unlike the sfDoctrinePlugin AFAICT). So things should change in DBAL, not here.

[stof]

Doctrine 2.3 (i.e. the current master branch) now has a way to register the mapping types directly from the type class. So when using 2.3, you don't need to use the mapping_types key anymore if you update your custom type to overwrite the new methods with the needed logic (the default implementation of the methods are empty methods).