If all that's different between your three "workhorse" programs is the SQL, why not read/run the SQL in the main program?

$dbh->do(<<SQL);
-- create first temp table
SQL

$dbh->do(<<SQL);
-- create second temp table
SQL

$dbh->do(<<SQL);
-- create third temp table
SQL
[download]

... or read the SQL from three files and run that SQL:

for my $file ("first.sql", "second.sql", "third.sql") {
    open my $fh, '<', $file or die "$file: $!";
    local $/;
    my $sql = <$fh>;
    $dbh->do( $sql );
}
[download]

... or, if you prefer a canned solution, take a look at DBIx::RunSQL, which runs SQL from strings or files, and has some (rough) logic to execute multiple SQL statements from a single file.