Error While inserting username and pass word into database - bash

Question

I am trying to insert following data in psql and its showing me weird error.
-bash-4.1$ psql -t -d mydb -c 'insert into ftp_mgr (id, info) values("192.168.1.12", '{"username": "Administrator", "password": "abc456$", "serverAddr":"192.168.1.12"}');'
psql: warning: extra command-line argument "password:" ignored
psql: warning: extra command-line argument "abc456$," ignored
psql: warning: extra command-line argument "serverAddr:192.168.1.12});" ignored
psql: FATAL: role "Administrator," does not exist

Answer 1

This is nothing to do with PostgreSQL. It's a shell quoting problem.
You cannot nest single quotes in bash. So this:
'insert into ftp_mgr (id, info) values("192.168.1.12", '{"username": "Administrator", "password": "abc456$", "serverAddr":"192.168.1.12"}');'
is read up to:
'insert ...'{
and the { is *not part of the quoted string. So the shell tries to intepret {"username": "Administrator", "password": "abc456$", "serverAddr":"192.168.1.12"} as a shell command.
The simplest thing to do here is to use a quoted here-document to avoid the need to deal with ' literal quoting mixing with the shell's quoting:
psql -t -d mydb <<'__END__'
insert into ftp_mgr (id, info) values
("192.168.1.12", '{"username": "Administrator", "password": "abc456$", "serverAddr":"192.168.1.12"}');
__END__
The quotes around the here-document tag are important. If you leave them out then bash still looks for and replaces $variable strings, etc, within the here-document text. That can be really handy, but it's clearly not what you want in this case.
if you must do it with -c you have a couple of options:
Use the shell's string concatenation. Whenever you want a single-quote, end the current single quoted string, write "'", and open a new single quoted string. So you'd write:
'insert ... values(..., '"'"'{"....
Confusing to read, isn't it? The first ' ends the single-quoted shell string. Then "'" is a single quote, quoted by double quotes that're consumed by the shell. Then the next ' begins a new single-quoted string.
That's horrible to read, and it's not much better written as:
'insert ... values(..., '\''{"....
so personally, when I need single quotes within an argument string I either double-quote the whole string and backslash-escape shell metacharacters:
"insert into ftp_mgr (id, info) values(\"192.168.1.12\", '{\"username\": \"Administrator\", \"password\": \"abc456\$\", \"serverAddr\":\"192.168.1.12\"}');"
... or where possible I use a quoted here-document to get around the whole horrifying mess.
My preference is to just avoid the shell for this kind of thing and use a simple Python script.
import psycopg2
conn = psycopg2.connect('dbname=postgres')
curs = conn.cursor()
curs.execute(r'insert into ftp_mgr (id, info) values(%s, %s);', (
r'192.168.1.12',
r'{"username": "Administrator", "password": "abc456$", "serverAddr":"192.168.1.12"}'
))
Python's support for raw-strings (r''), triple quote strings ("""), etc make this sort of thing much easier.