I have a Perl script inserting data into Postgres according to a pipe delimited text file. Sometimes, a field is null (as expected). However, Perl makes this field into an empty string and the Postgres insert statement fails.

Here's a snippet of code:

use DBI;

#Connect to the database.
$dbh=DBI->connect('dbi:Pg:dbname=mydb','mydb','mydb',{AutoCommit=>1,RaiseError=>1,PrintError=>1});

#Prepare an insert.
$sth=$dbh->prepare("INSERT INTO mytable (field0,field1) SELECT ?,?");

while (<>){
    #Remove the whitespace
    chomp;

    #Parse the fields.
    @field=split(/\|/,$_);

    print "$_\n";

    #Do the insert.
    $sth->execute($field[0],$field[1]);
}

And if the input is:

a|1
b|
c|3

EDIT: Use this input instead.

a|1|x
b||x
c|3|x

It will fail at b|.

DBD::Pg::st execute failed: ERROR:  invalid input syntax for integer: ""

I just want it to insert a null on field1 instead. Any ideas?

EDIT: I simplified the input at the last minute. The old input actually made it work for some reason. So now I changed the input to something that will make the program fail. Also note that field1 is a nullable integer datatype.