Sorry about that - PostgreSQL does let you concatenate ('||') text fields. It's been awhile since I had to deal with SQLServer weirdness.

Well then you're either left with running a transaction around your read/append/write or CAST the text field to varchar then concat (assuming the data can be cast).

I would go for the transaction approach, you'll be sure it'll work with any kind of data.

As for the ugliness it should be easy to make a method to hide the $dbh->{AutoCommit} = 0 (or $dbh->begin_work), read, append, update, $dbh->commit. Don't forget to turn AutoCommit off if it's on. In fact I would just add that in there to be safe.

local $dbh->{AutoCommit} = 0;
local $dbh->{RaiseError} = 1; 
# You can RaiseError and eval the transaction
# or you can check $sth->err each time and rollback

eval {
      ##Do your read and write here
      $dbh->commit; 
};
if ($@) {
      warn "append failed $@";
      $dbh->rollback;
}
[download]

UPDATE: something similar to this

sub append_to_text {
    my $dbh   = shift;
    my $table = shift;
    my $id    = shift;
    my $col   = shift;
    my $data  = shift;

    local $dbh->{RaiseError} = 1;
    eval {
        $dbh->begin_work();
        my $read = qq| 
            SELECT $col FROM $table 
                         WHERE id = ? 
             |;

        my $update = qq|
            UPDATE $table SET $col = ?
                         WHERE id = ?
            |;
        
        my $sth_read = $dbh->prepare($read);
        $sth_read->execute($id);
        my $row = $sth_read->fetchrow_hashref();
        $sth_read->finish();
        my $current = $row->{$col};
        $current .= $data;
        
        my $rtn = $dbh->do($update,undef,$current,$id);
        $dbh->commit() if ($rtn);
    };    
    if ($@) {
          warn "Append Failed: $@\nStatement: $DBI::lasth->{Statement}
+";
          eval { $dbh->rollback };
        }    
    
}
[download]

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