PostgreSQL, Second Edition

Client 2—Adding Error Checking

client1.pl didn't do any error checking at all. The error messages that you saw were produced by DBI or DBD::Pg, not by the script. For simple applications, it might be sufficient to let DBI handle errors, but in more complex cases, you probably want some other options.

Let's start by modifying the previous client so that it prints its own error message if something goes wrong. Listing 14.4 shows the resulting code.

Listing 14.4. client2a.pl

1 #!/usr/bin/perl -W 2 # 3 # Filename: client2a.pl 4 # 5 6 use strict; 7 use DBI; 8 9 my $dbh = DBI->connect( "dbi:Pg:" ) 10 or die "Can't connect to PostgreSQL: $DBI::errstr ($DBI::err)\n"; 11 12 $dbh->disconnect();

This script detects connect() failures by examining the ...