Question

For my UPDATE statement on PostgreSQL (from Perl via DBI and DBD::Pg) I want to bind a value like this:

my $sql = 'UPDATE mytable SET foo = % WHERE id = 42';
my $foo_value = 23;
$dbh->do($sql, {}, $foo_value);

This gives the following error in the do() line:

DBD::Pg::db do failed: called with 1 bind variable when 0 are needed at...

I tried other syntaxes for placeholders, $1 and ?. Both fail with

DBD::Pg::db do failed: ERROR:  invalid input syntax for type numeric: "" at...

What is the correct syntax?

Answer 1

The ? character is the correct placeholder.

my $sql = 'UPDATE mytable SET foo = ? WHERE id = 42';
my $foo_value = 23;
$dbh->do($sql, undef, $foo_value);