my $dsn = "dbi:SQLite:$dbname";
    $dbh = DBI->connect(
        $dsn, undef, undef,
        {   PrintError                 => 0,
            RaiseError                 => 1,
            AutoCommit                 => 1,
            sqlite_see_if_its_a_number => 1,
            sqlite_unicode             => 1
        }
        )
        or die("Cannot connect to the database: $DBI::errstr ($DBI::err) \n");
    my $self = { dbh => $dbh };
    die "dbh undef " unless ($dbh);  
    # print "Dbman_sqlite->new\n";
     $self->{dbh}->trace(1, *STDOUT);

##</code><code>##

    my $sql  = "INSERT INTO authors (name, firstname) VALUES (?, ?);";
    $self->{st_insert_authors} = $self->{dbh}->prepare($sql);
    $sql= "UPDATE papers set year=? WHERE rero_id=?";
    $self->{st_update_papers} = $self->{dbh}->prepare($sql);
    $sql = "SELECT authorid FROM authors WHERE name=? AND firstname=?";
    $self->{st_select_authors} = $self->{dbh}->prepare($sql);
  ...

##</code><code>##

    $self->{st_select_authors}->execute($name, $firstname) or die  $self->{st_select_authors}->errstr;
     my $val_ar = $self->{st_select_authors}->fetchall_arrayref( {} );
     my $foundid;
     die Dumper $val_ar;
   #gives an empty array ref

##</code><code>##

:\docs\OA\entrees_liste>build_rerodb.pl -f out_181106.txt
    DBI::db=HASH(0x2bc47c4) trace level set to 0x0/1 (DBI @ 0x0/0) in DBI 1.636-ithread (pid 7692)
    <- prepare('INSERT INTO authors (name, firstname) VALUES (?, ?);')= ( DBI::st=HASH(0x2bc4d4c) ) [1 items] at Collabs_db.pm line 40
    <- prepare('UPDATE papers set year=? WHERE rero_id=?')= ( DBI::st=HASH(0x2bc6294) ) [1 items] at Collabs_db.pm line 42
    <- prepare('SELECT authorid FROM authors WHERE name=? AND firstname=?')= ( DBI::st=HASH(0x2bc645c) ) [1 items] at Collabs_db.pm line 44
    <- prepare('DELETE FROM papers WHERE rero_id=?')= ( DBI::st=HASH(0x2bc65f4) ) [1 items] at Collabs_db.pm line 46
    <- prepare('INSERT INTO papers (rero_id, doi, year) VALUES (?,?, ?)')= ( DBI::st=HASH(0x2bc678c) ) [1 items] at Collabs_db.pm line 48
    <- prepare('SELECT rero_id FROM papers WHERE rero_id=?')= ( DBI::st=HASH(0x2bc6924) ) [1 items] at Collabs_db.pm line 50
    <- prepare('DELETE FROM writtenby WHERE rero_id=?')= ( DBI::st=HASH(0x2bc6abc) ) [1 items] at Collabs_db.pm line 52
    <- prepare('SELECT authorid FROM writtenby WHERE rero_id=?')= ( DBI::st=HASH(0x2bc6c54) ) [1 items] at Collabs_db.pm line 54
    <- begin_work= ( 1 ) [1 items] at Collabs_db.pm line 294
    <- execute("11350")= ( '0E0' ) [1 items] at Collabs_db.pm line 70
    <- fetchall_arrayref(HASH(0x2aedef4))= ( [ HASH(0x2bbed1c) ] ) [1 items] row1 at Collabs_db.pm line 71
    <- execute(undef, 11350)= ( 1 ) [1 items] at Collabs_db.pm line 76
Use of uninitialized value $year in concatenation (.) or string at Collabs_db.pm line 77, <$FH> line 1.
    <- execute(11350)= ( '0E0' ) [1 items] at Collabs_db.pm line 85
    <- fetchall_arrayref(HASH(0x2587f34))= ( [ HASH(0x2bba87c) ] ) [1 items] row1 at Collabs_db.pm line 86
    <- execute("Normand", " Bruce")= ( '0E0' ) [1 items] at Collabs_db.pm line 99
    <- fetchall_arrayref(HASH(0x2505b94))= ( [ ] ) [1 items] at Collabs_db.pm line 100
$VAR1 = [];