PostgreSQL Database psql Command Line Query

Sometime psql command line query can be useful when it comes to Bash script processing. There are data stored in PostgreSQL database and I would like to write a bash script to massage the data into report. Example below show query to PostgreSQL database by using the psql command.

psql is connecting to accounting database, query from members table and out the result into a txt file name member-email-address.txt.

-t – Return result only, do not result with table name.
-A – By default, returned result will have white space, this is to remove the white space.
-o – Output the result into a file.