Escaping single quotes in shell for postgresql

Question

I'm trying to execute SQK through psql under postgres account. I'm able run SQL that doesn't contain quotes

root@server:/home/rosta/SCRIPTS# su postgres -c "psql -c 'SELECT NOW()'"
              now
-------------------------------
2014-06-07 09:38:17.120368+02
(1 row)

The problem appears with an SQL query that contains quotes like SELECT 'hi'. I'm testing with simple 'hi', but I would like to execute something like this from a shell script.

su postgres -c "psql -c 'create database $DB_NAME template=template0 encoding='utf8' owner=aaa lc_collate='cs_CZ.utf8''"

Can anyone advise me how to escape quotes around encoding and collate in the command above

Some of my tests:

root@server:/home/rosta/SCRIPTS# su postgres -c "psql -c 'SELECT \'hi\''"
bash: -c: line 0: unexpected EOF while looking for matching `''
bash: -c: line 1: syntax error: unexpected end of file
root@server:/home/rosta/SCRIPTS# su postgres -c "psql -c 'SELECT \\'hi\\''"
bash: -c: line 0: unexpected EOF while looking for matching `''
bash: -c: line 1: syntax error: unexpected end of file
root@server:/home/rosta/SCRIPTS# su postgres -c 'psql -c \'SELECT \\'hi\\'\''

Answer 1

What I usually do is use double quotes ( " ) for postgres -c 's argument and escaped double quotes ( \\" ) for psql -c 's argument. That way, I can use single quotes ( ' ) inside the SQL string with no problem:

[root@mycomputer ~]# su postgres -c "psql -c \"SELECT 'hi'  \" "
 ?column? 
----------
 hi
(1 row)

Answer 2

Simplest way is to use a 'here document' , which ignores all quoting:

#!/bin/sh
DB_NAME=my_data_base

psql -U postgres postgres <<STOP_IT
create database $DB_NAME template=template0
  encoding='utf8'
  owner=aaa
  lc_collate='cs_CZ.utf8'
  ;
STOP_IT