# postgresql - basic usage ###### tags: `postgresql` `database` ``` # login postgresql database /usr/share/postgresql $ psql --username=<username> /usr/share/postgresql $ psql --username=mattermost psql (9.4.20) Type "help" for help. ``` ``` # list databases mattermost-# \list Or mattermost-# \l Or mattermost-# select datname from pg_database; # Show more details mattermost-# \l+ ``` ``` # connect to a database mattermost-# \connect <database name> ``` ``` # show tables mattermost-# \dt ``` ``` # select sql mattermost=# SELECT * FROM <table name>; ``` ``` # describe a table mattermost=# \d+ <table name>; ```