docker-composeでpostgressのデータベースにアクセスする

$docker-compose exec db bash

#psql -d postgres -U username
postgres=# \l
                                       List of databases
          Name          |  Owner   | Encoding |  Collate   |   Ctype    |   Access privileges
------------------------+----------+----------+------------+------------+-----------------------
 hoge                   | postgres | UTF8     | en_US.utf8 | en_US.utf8 |
 fuga                   | postgres | UTF8     | en_US.utf8 | en_US.utf8 |
 postgres               | postgres | UTF8     | en_US.utf8 | en_US.utf8 |

#\c hoge
You are now connected to database "hoge" as user "username".