Redmine

Hello,

I'm looking for a way to export the issues from Redmine 3.0.3 to another instance of Redmine 3.0.3 (both are using PostgreSQL 9.4)
I understood some stuff about relations of the table issues but it's not enough.

If someone has the Redmine entity-relationship diagram (ERD) of the version 3.0.3, it will help me to build my query.

Thank you