Hi all,

I am curious to know if there is a "cleaner" way to check for and handle NULL values, when processing the result set of an SQL query.
Please consider the following code (assume -w and use strict): 
    178     #   Build the first half of the INSERT
    179     #   using the field list we got from the earlier DESCRIBE
    180     #   Of course we only do this if we have any rows to inser
+t
    181     if ($affected_rows) {
    182         my $base_insert = "INSERT IGNORE INTO $thisTable (host
+name, host_id, "
    183             . join("," , @fields)
    184             . ") VALUES (\"$site_hostname\", \"$site_id\", ";
    185
    186         #   Now we iterate through the result set from the pre
+vious query
    187         #   completing each INSERT as we go, and dumping them 
+all into a big list
    188         while (my @row = $dbq->fetchrow_array) {
    189             #   Need to check for NULL's
    190             for(@row) { $_ = "NULL" if !defined $_; }
    191             my $this_insert = $base_insert
    192                 . join("," , map {qq("$_")} @row)
    193                 . ");";
    194             push @central_inserts, $this_insert;
    195         }
    196     }

[download]
The above code is part of a script that is used to backup tables from several remote hosts to a central database. It works "okay", but after running it a few times I discovered that it wasn't correctly handling NULL's.
So I inserted: 
for(@row) { $_ = "NULL" if !defined $_; }

[download]
at line 190.

Is that a reasonable approach?
Is there a better (cleaner) way?

Thanks,
--Darren

In reply to DBI - Handling NULL values by McDarren

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