Sample pgsql function and its usage

--First, run this ode, it will create a function
create function update_user_groups(userId int)
returns void
language plpgsql
as
$$
DECLARE
 i  INTEGER := (select max(sort_order) from user_groups where user_id=userId);
begin
for r in 1000006..1000026 loop
i = i+1;
insert into user_groups values(userId, r, i) ON CONFLICT DO NOTHING;
end loop;
end;
$$;
--If everything ok, this will create a function in your functions list

--Then call the function u created giving arguments (ex userId in this case)
select update_user_groups(103);

Create User Script

USERNAME=$1
sudo adduser $USERNAME  --disabled-password  --gecos ""
cd /home/$USERNAME
sudo mkdir .ssh
sudo touch .ssh/authorized_keys
sudo chmod 600 .ssh/authorized_keys
sudo ssh-keygen -b 2048 -t rsa -f /home/$USERNAME/$USERNAME -q -N ""
sudo cp /home/$USERNAME/$USERNAME.pub  /home/$USERNAME/.ssh/authorized_keys
sudo chown  $USERNAME:$USERNAME  /home/$USERNAME/.ssh/
sudo chown  $USERNAME:$USERNAME  /home/$USERNAME/.ssh/authorized_keys
sudo usermod -aG sudo $USERNAME
sudo passwd $USERNAME

# to scp the private key, lets have it copied here
sudo cp /home/$USERNAME/$USERNAME  /home/ubuntu/
cd /home/ubuntu/
sudo chown ubuntu:ubuntu $USERNAME