Hi Roland,
Am 13.01.2012 um 12:33 schrieb Roland Philibert:
> Hi all,
> I am new on the subject..please excuse my ignorance!
I am just a user of DBIx::Class, so there might be even better ways than I
suggest.
> Am trying to find the most efficient way of doing a simple copy of rows
> such as in sql: INSERT INTO table (col1, col2, col3, ...) SELECT col1,
> col2, col3, ... FROM table WHERE primarykey = xx
If you intend to copy single rows, you might like to use the ->copy() method of
DBIx::Class::Row
my $original_record = $schema->resultset('MyTable')->find($id);
my $new_record = $original_record->copy();
However, the SQL generated will use two statements instead of one in your
pure-SQL example above.
If you plan to copy many rows at once, you could retrieve your rows, convert
your result into an array of hashrefs and feed this structure into
DBIx::Class::Schema's ->populate() method. The code looks a bit more
complicated, but also yields only 2 SQL Statements, the number of records is
irrelevant.
my $resultset = $schema->resultset('MyTable')->search( { conditions }, {
columns => [ ... ] } );
$resultset->result_class('DBIx::Class::ResultClass::HashRefInflator');
my @records = $resultset->all;
$schema->populate(MyTable => \@records) if @records;
The downside of the latter solution is that you explicitly must build the list
of columns you want to copy yourself (or programatically by scanning thru your
table's columns). Otherwise your primary key or unique constraints might
complain their values' duplication.
I hope I could help.
>
> Many thanks.
> Roland
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Best,
Wolfgang Kinkeldei
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