Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question: 

app->attr(dbh => sub {

   my $self = shift;
   my $dsn  = 'dbi:Oracle:schema';
   my $usr  = 'Scott';
   my $pas  = 'tiger';
   my $dbh  = $DBI->connect_cached( $dsn, $usr, $pas );

   return $dbh;
}

# later

get '/query' => sub{

   my $c = shift;
   my $dbh = $c->app->dbh;
   my $sql = 'SQL QUERY HERE';
   my $sth = $dbh->pepare_cached( $sql );
   my $details = $dbh->selectall_arrayref( $sql, { Slice = {} });

  # and so on
};

[download]
IN above example, I do prepare cached, but don't know how to call the cached query each time the route is visitied. 1. is my initial DBH setup optimal? 2. How do I make use of prepare_cached? Thanks

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Re: Mojo - Prepare cached query
by tobyink (Canon) on Mar 03, 2020 at 13:37 UTC

    I've not really used Mojo, but I think you probably want something like this...

    app->attr(dbh => sub {
   my $self = shift;
   my $dsn  = 'dbi:Oracle:schema';
   my $usr  = 'Scott';
   my $pas  = 'tiger';
   my $dbh  = DBI->connect_cached( $dsn, $usr, $pas );
   return $dbh;
});

app->attr(cached_query => sub {
   my $self = shift;
   my $sql  = 'SQL QUERY HERE';
   return $self->dbh->prepare_cached( $sql );
});

# later

get '/query' => sub{
   my $c   = shift;
   my $dbh = $c->app->dbh;
   my $sth = $c->app->cached_query;
   
   # probably pull @values out from GET query or POST data
   my @values = do { ... };
   
   my $results = $dbh->selectall_arrayref($sth, {}, @values);
   
   # and so on
};

    [download]
    toby döt ink
[reply]
[d/l]
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