Here it is:
Find out the postgres docker
[root@fuel /[root@fuel /
[root@fuel /]# sudo su - postgres
-
Type "help" for help.
postgres=#
Use "nailgun" database
postgres=# \c nailgun
You are now connected to database "nailgun" as user "postgres".
List all tables in database
nailgun=# \dtLook "tasks" table schema
nailgun=# \d tasks
Use SQL to select the data in table
nailgun=# select * from information_schema. columns where table_name = tasks;