Hi,
I am beginner both of docker and postgresql.
How do i upgrade docker postgresql 9.5 into 9.6 without losing my
current database?
fyi: im using ubuntu verison 14 and docker 17.09
More of a Docker forum question than PostgreSQL. It depends on whether you setup a distinct data container and/or mounted a host location into the container to store the data. In that case you should be able to link that external dependency into the new runtime container in the same manner as it is linked into the existing one.
If the data is directly within the runtime container it will be considerably more difficult - though pg_dump/pg_restore might prove easiest to accomplish.
David J.