pgcsv
pgcsv executes PostgreSQL sql queries and output the results in a csv format. It accepts sql queries via stdin and outputs to stdout. It is recommended that you validate the correctness of your query elsewhere, perhaps in psql, before running pgcsv.
Usage
# basic example
pgcsv -h <dbhost> -p <dbport> < my_commands.sql > results.csv
# you can compress your output using a pipe
pgcsv -h <dbhost> -p <dbport> < my_commands.sql | gzip - > results.csv.gz