=head3 Resolving conditions and attributes
-When a resultset is chained from another resultset, conditions and
-attributes with the same keys need resolving.
+When a resultset is chained from another resultset (ie:
+C<my $new_rs = $old_rs->search(\%extra_cond, \%attrs)>), conditions
+and attributes with the same keys need resolving.
-L</join>, L</prefetch>, L</+select>, L</+as> attributes are merged
-into the existing ones from the original resultset.
+If any of L</columns>, L</select>, L</as> are present, they reset the
+original selection, and start the selection "clean".
+
+The L</join>, L</prefetch>, L</+columns>, L</+select>, L</+as> attributes
+are merged into the existing ones from the original resultset.
The L</where> and L</having> attributes, and any search conditions, are
merged with an SQL C<AND> to the existing condition from the original
# older deprecated name, use only if {columns} is not there
if (my $c = delete $new_attrs->{cols}) {
+ carp_unique( "Resultset attribute 'cols' is deprecated, use 'columns' instead" );
if ($new_attrs->{columns}) {
carp "Resultset specifies both the 'columns' and the legacy 'cols' attributes - ignoring 'cols'";
}
my ($self, $attrs) = @_;
# legacy syntax
- $attrs->{'+columns'} = $self->_merge_attr($attrs->{'+columns'}, delete $attrs->{include_columns})
- if exists $attrs->{include_columns};
+ if ( exists $attrs->{include_columns} ) {
+ carp_unique( "Resultset attribute 'include_columns' is deprecated, use '+columns' instead" );
+ $attrs->{'+columns'} = $self->_merge_attr(
+ $attrs->{'+columns'}, delete $attrs->{include_columns}
+ );
+ }
# columns are always placed first, however
# Run the query, passing the result_class since it should propagate for find
my $rs = $self->search ($final_cond, {result_class => $self->result_class, %$attrs});
- if (keys %{$rs->_resolved_attrs->{collapse}}) {
+ if ($rs->_resolved_attrs->{collapse}) {
my $row = $rs->next;
carp "Query returned more than one row" if $rs->next;
return $row;
my $attrs = { %{$self->_resolved_attrs} };
- if (keys %{$attrs->{collapse}}) {
- $self->throw_exception(
- 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
- );
- }
+ $self->throw_exception(
+ 'single() can not be used on resultsets prefetching has_many. Use find( \%cond ) or next() instead'
+ ) if $attrs->{collapse};
if ($where) {
if (defined $attrs->{where}) {
}
}
- my @data = $self->result_source->storage->select_single(
+ my $data = [ $self->result_source->storage->select_single(
$attrs->{from}, $attrs->{select},
$attrs->{where}, $attrs
- );
-
- return (@data ? ($self->_construct_object(@data))[0] : undef);
+ )];
+ return undef unless @$data;
+ $self->{_stashed_rows} = [ $data ];
+ $self->_construct_results->[0];
}
sub next {
my ($self) = @_;
+
if (my $cache = $self->get_cache) {
$self->{all_cache_position} ||= 0;
return $cache->[$self->{all_cache_position}++];
}
+
if ($self->{attrs}{cache}) {
delete $self->{pager};
$self->{all_cache_position} = 1;
return ($self->all)[0];
}
- if ($self->{stashed_objects}) {
- my $obj = shift(@{$self->{stashed_objects}});
- delete $self->{stashed_objects} unless @{$self->{stashed_objects}};
- return $obj;
- }
- my @row = (
- exists $self->{stashed_row}
- ? @{delete $self->{stashed_row}}
- : $self->cursor->next
- );
- return undef unless (@row);
- my ($row, @more) = $self->_construct_object(@row);
- $self->{stashed_objects} = \@more if @more;
- return $row;
-}
-sub _construct_object {
- my ($self, @row) = @_;
+ return shift(@{$self->{_stashed_results}}) if @{ $self->{_stashed_results}||[] };
+
+ $self->{_stashed_results} = $self->_construct_results
+ or return undef;
- my $info = $self->_collapse_result($self->{_attrs}{as}, \@row)
- or return ();
- my @new = $self->result_class->inflate_result($self->result_source, @$info);
- @new = $self->{_attrs}{record_filter}->(@new)
- if exists $self->{_attrs}{record_filter};
- return @new;
+ return shift @{$self->{_stashed_results}};
}
-sub _collapse_result {
- my ($self, $as_proto, $row) = @_;
+# Constructs as many results as it can in one pass while respecting
+# cursor laziness. Several modes of operation:
+#
+# * Always builds everything present in @{$self->{_stashed_rows}}
+# * If called with $fetch_all true - pulls everything off the cursor and
+# builds all result structures (or objects) in one pass
+# * If $self->_resolved_attrs->{collapse} is true, checks the order_by
+# and if the resultset is ordered properly by the left side:
+# * Fetches stuff off the cursor until the "master object" changes,
+# and saves the last extra row (if any) in @{$self->{_stashed_rows}}
+# OR
+# * Just fetches, and collapses/constructs everything as if $fetch_all
+# was requested (there is no other way to collapse except for an
+# eager cursor)
+# * If no collapse is requested - just get the next row, construct and
+# return
+sub _construct_results {
+ my ($self, $fetch_all) = @_;
- my @copy = @$row;
+ my $rsrc = $self->result_source;
+ my $attrs = $self->_resolved_attrs;
- # 'foo' => [ undef, 'foo' ]
- # 'foo.bar' => [ 'foo', 'bar' ]
- # 'foo.bar.baz' => [ 'foo.bar', 'baz' ]
+ if (
+ ! $fetch_all
+ and
+ ! $attrs->{order_by}
+ and
+ $attrs->{collapse}
+ and
+ my @pcols = $rsrc->primary_columns
+ ) {
+ # default order for collapsing unless the user asked for something
+ $attrs->{order_by} = [ map { join '.', $attrs->{alias}, $_} @pcols ];
+ $attrs->{_ordered_for_collapse} = 1;
+ $attrs->{_order_is_artificial} = 1;
+ }
- my @construct_as = map { [ (/^(?:(.*)\.)?([^.]+)$/) ] } @$as_proto;
+ my $cursor = $self->cursor;
- my %collapse = %{$self->{_attrs}{collapse}||{}};
+ # this will be used as both initial raw-row collector AND as a RV of
+ # _construct_results. Not regrowing the array twice matters a lot...
+ # a surprising amount actually
+ my $rows = delete $self->{_stashed_rows};
- my @pri_index;
+ my $did_fetch_all = $fetch_all;
- # if we're doing collapsing (has_many prefetch) we need to grab records
- # until the PK changes, so fill @pri_index. if not, we leave it empty so
- # we know we don't have to bother.
+ if ($fetch_all) {
+ # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
+ $rows = [ ($rows ? @$rows : ()), $cursor->all ];
+ }
+ elsif( $attrs->{collapse} ) {
- # the reason for not using the collapse stuff directly is because if you
- # had for e.g. two artists in a row with no cds, the collapse info for
- # both would be NULL (undef) so you'd lose the second artist
+ $attrs->{_ordered_for_collapse} = (!$attrs->{order_by}) ? 0 : do {
+ my $st = $rsrc->schema->storage;
+ my @ord_cols = map
+ { $_->[0] }
+ ( $st->_extract_order_criteria($attrs->{order_by}) )
+ ;
- # store just the index so we can check the array positions from the row
- # without having to contruct the full hash
+ my $colinfos = $st->_resolve_column_info($attrs->{from}, \@ord_cols);
- if (keys %collapse) {
- my %pri = map { ($_ => 1) } $self->result_source->_pri_cols;
- foreach my $i (0 .. $#construct_as) {
- next if defined($construct_as[$i][0]); # only self table
- if (delete $pri{$construct_as[$i][1]}) {
- push(@pri_index, $i);
+ for (0 .. $#ord_cols) {
+ if (
+ ! $colinfos->{$ord_cols[$_]}
+ or
+ $colinfos->{$ord_cols[$_]}{-result_source} != $rsrc
+ ) {
+ splice @ord_cols, $_;
+ last;
+ }
+ }
+
+ # since all we check here are the start of the order_by belonging to the
+ # top level $rsrc, a present identifying set will mean that the resultset
+ # is ordered by its leftmost table in a tsable manner
+ (@ord_cols and $rsrc->_identifying_column_set({ map
+ { $colinfos->{$_}{-colname} => $colinfos->{$_} }
+ @ord_cols
+ })) ? 1 : 0;
+ } unless defined $attrs->{_ordered_for_collapse};
+
+ if (! $attrs->{_ordered_for_collapse}) {
+ $did_fetch_all = 1;
+
+ # instead of looping over ->next, use ->all in stealth mode
+ # *without* calling a ->reset afterwards
+ # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
+ if (! $cursor->{_done}) {
+ $rows = [ ($rows ? @$rows : ()), $cursor->all ];
+ $cursor->{_done} = 1;
}
}
}
- # no need to do an if, it'll be empty if @pri_index is empty anyway
+ if (! $did_fetch_all and ! @{$rows||[]} ) {
+ # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
+ if (scalar (my @r = $cursor->next) ) {
+ $rows = [ \@r ];
+ }
+ }
- my %pri_vals = map { ($_ => $copy[$_]) } @pri_index;
+ return undef unless @{$rows||[]};
- my @const_rows;
+ my @extra_collapser_args;
+ if ($attrs->{collapse} and ! $did_fetch_all ) {
- do { # no need to check anything at the front, we always want the first row
+ @extra_collapser_args = (
+ # FIXME SUBOPTIMAL - we can do better, cursor->next/all (well diff. methods) should return a ref
+ sub { my @r = $cursor->next or return; \@r }, # how the collapser gets more rows
+ ($self->{_stashed_rows} = []), # where does it stuff excess
+ );
+ }
- my %const;
+ # hotspot - skip the setter
+ my $res_class = $self->_result_class;
- foreach my $this_as (@construct_as) {
- $const{$this_as->[0]||''}{$this_as->[1]} = shift(@copy);
- }
+ my $inflator_cref = $self->{_result_inflator}{cref} ||= do {
+ $res_class->can ('inflate_result')
+ or $self->throw_exception("Inflator $res_class does not provide an inflate_result() method");
+ };
- push(@const_rows, \%const);
+ my $infmap = $attrs->{as};
- } until ( # no pri_index => no collapse => drop straight out
- !@pri_index
- or
- do { # get another row, stash it, drop out if different PK
- @copy = $self->cursor->next;
- $self->{stashed_row} = \@copy;
+ $self->{_result_inflator}{is_core_row} = ( (
+ $inflator_cref
+ ==
+ ( \&DBIx::Class::Row::inflate_result || die "No ::Row::inflate_result() - can't happen" )
+ ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_core_row};
- # last thing in do block, counts as true if anything doesn't match
+ $self->{_result_inflator}{is_hri} = ( (
+ ! $self->{_result_inflator}{is_core_row}
+ and
+ $inflator_cref == (
+ require DBIx::Class::ResultClass::HashRefInflator
+ &&
+ DBIx::Class::ResultClass::HashRefInflator->can('inflate_result')
+ )
+ ) ? 1 : 0 ) unless defined $self->{_result_inflator}{is_hri};
- # check xor defined first for NULL vs. NOT NULL then if one is
- # defined the other must be so check string equality
- grep {
- (defined $pri_vals{$_} ^ defined $copy[$_])
- || (defined $pri_vals{$_} && ($pri_vals{$_} ne $copy[$_]))
- } @pri_index;
+ if (! $attrs->{_related_results_construction}) {
+ # construct a much simpler array->hash folder for the one-table cases right here
+ if ($self->{_result_inflator}{is_hri}) {
+ for my $r (@$rows) {
+ $r = { map { $infmap->[$_] => $r->[$_] } 0..$#$infmap };
}
- );
-
- my $alias = $self->{attrs}{alias};
- my $info = [];
-
- my %collapse_pos;
-
- my @const_keys;
-
- foreach my $const (@const_rows) {
- scalar @const_keys or do {
- @const_keys = sort { length($a) <=> length($b) } keys %$const;
- };
- foreach my $key (@const_keys) {
- if (length $key) {
- my $target = $info;
- my @parts = split(/\./, $key);
- my $cur = '';
- my $data = $const->{$key};
- foreach my $p (@parts) {
- $target = $target->[1]->{$p} ||= [];
- $cur .= ".${p}";
- if ($cur eq ".${key}" && (my @ckey = @{$collapse{$cur}||[]})) {
- # collapsing at this point and on final part
- my $pos = $collapse_pos{$cur};
- CK: foreach my $ck (@ckey) {
- if (!defined $pos->{$ck} || $pos->{$ck} ne $data->{$ck}) {
- $collapse_pos{$cur} = $data;
- delete @collapse_pos{ # clear all positioning for sub-entries
- grep { m/^\Q${cur}.\E/ } keys %collapse_pos
- };
- push(@$target, []);
- last CK;
- }
- }
- }
- if (exists $collapse{$cur}) {
- $target = $target->[-1];
- }
- }
- $target->[0] = $data;
- } else {
- $info->[0] = $const->{$key};
+ }
+ # FIXME SUBOPTIMAL this is a very very very hot spot
+ # while rather optimal we can *still* do much better, by
+ # building a smarter Row::inflate_result(), and
+ # switch to feeding it data via a much leaner interface
+ #
+ # crude unscientific benchmarking indicated the shortcut eval is not worth it for
+ # this particular resultset size
+ elsif (@$rows < 60) {
+ for my $r (@$rows) {
+ $r = $inflator_cref->($res_class, $rsrc, { map { $infmap->[$_] => $r->[$_] } (0..$#$infmap) } );
}
}
+ else {
+ eval sprintf (
+ '$_ = $inflator_cref->($res_class, $rsrc, { %s }) for @$rows',
+ join (', ', map { "\$infmap->[$_] => \$_->[$_]" } 0..$#$infmap )
+ );
+ }
+ }
+ # Special-case multi-object HRI (we always prune, and there is no $inflator_cref pass)
+ elsif ($self->{_result_inflator}{is_hri}) {
+ ( $self->{_row_parser}{hri} ||= $rsrc->_mk_row_parser({
+ eval => 1,
+ inflate_map => $infmap,
+ selection => $attrs->{select},
+ collapse => $attrs->{collapse},
+ premultiplied => $attrs->{_main_source_premultiplied},
+ hri_style => 1,
+ prune_null_branches => 1,
+ }) )->($rows, @extra_collapser_args);
+ }
+ # Regular multi-object
+ else {
+ my $parser_type = $self->{_result_inflator}{is_core_row} ? 'classic_pruning' : 'classic_nonpruning';
+
+ ( $self->{_row_parser}{$parser_type} ||= $rsrc->_mk_row_parser({
+ eval => 1,
+ inflate_map => $infmap,
+ selection => $attrs->{select},
+ collapse => $attrs->{collapse},
+ premultiplied => $attrs->{_main_source_premultiplied},
+ prune_null_branches => $self->{_result_inflator}{is_core_row},
+ }) )->($rows, @extra_collapser_args);
+
+ $_ = $inflator_cref->($res_class, $rsrc, @$_) for @$rows;
}
- return $info;
+ # The @$rows check seems odd at first - why wouldn't we want to warn
+ # regardless? The issue is things like find() etc, where the user
+ # *knows* only one result will come back. In these cases the ->all
+ # is not a pessimization, but rather something we actually want
+ carp_unique(
+ 'Unable to properly collapse has_many results in iterator mode due '
+ . 'to order criteria - performed an eager cursor slurp underneath. '
+ . 'Consider using ->all() instead'
+ ) if ( ! $fetch_all and @$rows > 1 );
+
+ return $rows;
}
=head2 result_source
sub result_class {
my ($self, $result_class) = @_;
if ($result_class) {
- unless (ref $result_class) { # don't fire this for an object
- $self->ensure_class_loaded($result_class);
+
+ # don't fire this for an object
+ $self->ensure_class_loaded($result_class)
+ unless ref($result_class);
+
+ if ($self->get_cache) {
+ carp_unique('Changing the result_class of a ResultSet instance with cached results is a noop - the cache contents will not be altered');
+ }
+ # FIXME ENCAPSULATION - encapsulation breach, cursor method additions pending
+ elsif ($self->{cursor} && $self->{cursor}{_pos}) {
+ $self->throw_exception('Changing the result_class of a ResultSet instance with an active cursor is not supported');
}
+
$self->_result_class($result_class);
- # THIS LINE WOULD BE A BUG - this accessor specifically exists to
- # permit the user to set result class on one result set only; it only
- # chains if provided to search()
- #$self->{attrs}{result_class} = $result_class if ref $self;
+
+ delete $self->{_result_inflator};
}
$self->_result_class;
}
# this is a little optimization - it is faster to do the limit
# adjustments in software, instead of a subquery
- my $rows = delete $attrs->{rows};
- my $offset = delete $attrs->{offset};
+ my ($rows, $offset) = delete @{$attrs}{qw/rows offset/};
my $crs;
if ($self->_has_resolved_attr (qw/collapse group_by/)) {
my $tmp_attrs = { %$attrs };
# take off any limits, record_filter is cdbi, and no point of ordering nor locking a count
- delete @{$tmp_attrs}{qw/rows offset order_by record_filter for/};
+ delete @{$tmp_attrs}{qw/rows offset order_by _related_results_construction record_filter for/};
# overwrite the selector (supplied by the storage)
$tmp_attrs->{select} = $rsrc->storage->_count_select ($rsrc, $attrs);
$tmp_attrs->{as} = 'count';
- delete @{$tmp_attrs}{qw/columns/};
my $tmp_rs = $rsrc->resultset_class->new($rsrc, $tmp_attrs)->get_column ('count');
my $sub_attrs = { %$attrs };
# extra selectors do not go in the subquery and there is no point of ordering it, nor locking it
- delete @{$sub_attrs}{qw/collapse columns as select _prefetch_selector_range order_by for/};
+ delete @{$sub_attrs}{qw/collapse columns as select _related_results_construction order_by for/};
# if we multi-prefetch we group_by something unique, as this is what we would
# get out of the rs via ->next/->all. We *DO WANT* to clobber old group_by regardless
- if ( keys %{$attrs->{collapse}} ) {
+ if ( $attrs->{collapse} ) {
$sub_attrs->{group_by} = [ map { "$attrs->{alias}.$_" } @{
$rsrc->_identifying_column_set || $self->throw_exception(
'Unable to construct a unique group_by criteria properly collapsing the '
sub all {
my $self = shift;
if(@_) {
- $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
+ $self->throw_exception("all() doesn't take any arguments, you probably wanted ->search(...)->all()");
}
- return @{ $self->get_cache } if $self->get_cache;
-
- my @obj;
-
- if (keys %{$self->_resolved_attrs->{collapse}}) {
- # Using $self->cursor->all is really just an optimisation.
- # If we're collapsing has_many prefetches it probably makes
- # very little difference, and this is cleaner than hacking
- # _construct_object to survive the approach
- $self->cursor->reset;
- my @row = $self->cursor->next;
- while (@row) {
- push(@obj, $self->_construct_object(@row));
- @row = (exists $self->{stashed_row}
- ? @{delete $self->{stashed_row}}
- : $self->cursor->next);
- }
- } else {
- @obj = map { $self->_construct_object(@$_) } $self->cursor->all;
+ delete @{$self}{qw/_stashed_rows _stashed_results/};
+
+ if (my $c = $self->get_cache) {
+ return @$c;
}
- $self->set_cache(\@obj) if $self->{attrs}{cache};
+ $self->cursor->reset;
- return @obj;
+ my $objs = $self->_construct_results('fetch_all') || [];
+
+ $self->set_cache($objs) if $self->{attrs}{cache};
+
+ return @$objs;
}
=head2 reset
sub reset {
my ($self) = @_;
+
+ delete @{$self}{qw/_stashed_rows _stashed_results/};
$self->{all_cache_position} = 0;
$self->cursor->reset;
return $self;
my $attrs = { %{$self->_resolved_attrs} };
my $join_classifications;
- my $existing_group_by = delete $attrs->{group_by};
+ my ($existing_group_by) = delete @{$attrs}{qw(group_by _grouped_by_distinct)};
# do we need a subquery for any reason?
my $needs_subq = (
);
# make a new $rs selecting only the PKs (that's all we really need for the subq)
- delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_selector_range as/;
+ delete $attrs->{$_} for qw/select as collapse _related_results_construction/;
$attrs->{columns} = [ map { "$attrs->{alias}.$_" } @$idcols ];
$attrs->{group_by} = \ ''; # FIXME - this is an evil hack, it causes the optimiser to kick in and throw away the LEFT joins
my $subrs = (ref $self)->new($rsrc, $attrs);
# throw away the paging flags and re-run the count (possibly
# with a subselect) to get the real total count
my $count_attrs = { %$attrs };
- delete $count_attrs->{$_} for qw/rows offset page pager/;
+ delete @{$count_attrs}{qw/rows offset page pager/};
my $total_rs = (ref $self)->new($self->result_source, $count_attrs);
my $attrs = { %{ $self->_resolved_attrs } };
- # For future use:
- #
- # in list ctx:
- # my ($sql, \@bind, \%dbi_bind_attrs) = _select_args_to_query (...)
- # $sql also has no wrapping parenthesis in list ctx
- #
- my $sqlbind = $self->result_source->storage
- ->_select_args_to_query ($attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs);
-
- return $sqlbind;
+ $self->result_source->storage->_select_args_to_query (
+ $attrs->{from}, $attrs->{select}, $attrs->{where}, $attrs
+ );
}
=head2 find_or_new
sub related_resultset {
my ($self, $rel) = @_;
- $self->{related_resultsets} ||= {};
return $self->{related_resultsets}{$rel} ||= do {
my $rsrc = $self->result_source;
my $rel_info = $rsrc->relationship_info($rel);
#XXX - temp fix for result_class bug. There likely is a more elegant fix -groditi
delete @{$attrs}{qw(result_class alias)};
- my $new_cache;
+ my $related_cache;
if (my $cache = $self->get_cache) {
- if ($cache->[0] && $cache->[0]->related_resultset($rel)->get_cache) {
- $new_cache = [ map { @{$_->related_resultset($rel)->get_cache} }
- @$cache ];
- }
+ $related_cache = [ map
+ { @{$_->related_resultset($rel)->get_cache||[]} }
+ @$cache
+ ];
}
my $rel_source = $rsrc->related_source($rel);
where => $attrs->{where},
});
};
- $new->set_cache($new_cache) if $new_cache;
+ $new->set_cache($related_cache) if $related_cache;
$new;
};
}
# ->_resolve_join as otherwise they get lost - captainL
my $join = $self->_merge_joinpref_attr( $attrs->{join}, $attrs->{prefetch} );
- delete @{$attrs}{qw/join prefetch collapse group_by distinct select as columns +select +as +columns/};
+ delete @{$attrs}{qw/join prefetch collapse group_by distinct _grouped_by_distinct select as columns +select +as +columns/};
my $seen = { %{ (delete $attrs->{seen_join}) || {} } };
if $attrs->{select};
# assume all unqualified selectors to apply to the current alias (legacy stuff)
- for (@sel) {
- $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_";
- }
+ $_ = (ref $_ or $_ =~ /\./) ? $_ : "$alias.$_" for @sel;
- # disqualify all $alias.col as-bits (collapser mandated)
- for (@as) {
- $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_;
- }
+ # disqualify all $alias.col as-bits (inflate-map mandated)
+ $_ = ($_ =~ /^\Q$alias.\E(.+)$/) ? $1 : $_ for @as;
# de-duplicate the result (remove *identical* select/as pairs)
# and also die on duplicate {as} pointing to different {select}s
carp_unique ("Useless use of distinct on a grouped resultset ('distinct' is ignored when a 'group_by' is present)");
}
else {
+ $attrs->{_grouped_by_distinct} = 1;
# distinct affects only the main selection part, not what prefetch may
# add below.
$attrs->{group_by} = $source->storage->_group_over_selection (
}
}
- $attrs->{collapse} ||= {};
- if ($attrs->{prefetch}) {
+ # generate selections based on the prefetch helper
+ my $prefetch;
+ $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} )
+ if defined $attrs->{prefetch};
+
+ if ($prefetch) {
$self->throw_exception("Unable to prefetch, resultset contains an unnamed selector $attrs->{_dark_selector}{string}")
if $attrs->{_dark_selector};
- my $prefetch = $self->_merge_joinpref_attr( {}, delete $attrs->{prefetch} );
-
- my $prefetch_ordering = [];
+ $attrs->{collapse} = 1;
# this is a separate structure (we don't look in {from} directly)
# as the resolver needs to shift things off the lists to work
}
}
- my @prefetch =
- $source->_resolve_prefetch( $prefetch, $alias, $join_map, $prefetch_ordering, $attrs->{collapse} );
-
- # we need to somehow mark which columns came from prefetch
- if (@prefetch) {
- my $sel_end = $#{$attrs->{select}};
- $attrs->{_prefetch_selector_range} = [ $sel_end + 1, $sel_end + @prefetch ];
- }
+ my @prefetch = $source->_resolve_prefetch( $prefetch, $alias, $join_map );
push @{ $attrs->{select} }, (map { $_->[0] } @prefetch);
push @{ $attrs->{as} }, (map { $_->[1] } @prefetch);
+ }
- push( @{$attrs->{order_by}}, @$prefetch_ordering );
- $attrs->{_collapse_order_by} = \@$prefetch_ordering;
+ if ( List::Util::first { $_ =~ /\./ } @{$attrs->{as}} ) {
+ $attrs->{_related_results_construction} = 1;
+ }
+ else {
+ $attrs->{collapse} = 0;
+ }
+
+ # run through the resulting joinstructure (starting from our current slot)
+ # and unset collapse if proven unnesessary
+ #
+ # also while we are at it find out if the current root source has
+ # been premultiplied by previous related_source chaining
+ #
+ # this allows to predict whether a root object with all other relation
+ # data set to NULL is in fact unique
+ if ($attrs->{collapse}) {
+
+ if (ref $attrs->{from} eq 'ARRAY') {
+
+ if (@{$attrs->{from}} <= 1) {
+ # no joins - no collapse
+ $attrs->{collapse} = 0;
+ }
+ else {
+ # find where our table-spec starts
+ my @fromlist = @{$attrs->{from}};
+ while (@fromlist) {
+ my $t = shift @fromlist;
+
+ my $is_multi;
+ # me vs join from-spec distinction - a ref means non-root
+ if (ref $t eq 'ARRAY') {
+ $t = $t->[0];
+ $is_multi ||= ! $t->{-is_single};
+ }
+ last if ($t->{-alias} && $t->{-alias} eq $alias);
+ $attrs->{_main_source_premultiplied} ||= $is_multi;
+ }
+
+ # no non-singles remaining, nor any premultiplication - nothing to collapse
+ if (
+ ! $attrs->{_main_source_premultiplied}
+ and
+ ! List::Util::first { ! $_->[0]{-is_single} } @fromlist
+ ) {
+ $attrs->{collapse} = 0;
+ }
+ }
+ }
+
+ else {
+ # if we can not analyze the from - err on the side of safety
+ $attrs->{_main_source_premultiplied} = 1;
+ }
}
# if both page and offset are specified, produce a combined offset
$seen_keys->{$import_key} = 1; # don't merge the same key twice
}
- return $orig;
+ return @$orig ? $orig : ();
}
{
my $to_serialize = { %$self };
# A cursor in progress can't be serialized (and would make little sense anyway)
- delete $to_serialize->{cursor};
+ # the parser can be regenerated (and can't be serialized)
+ delete @{$to_serialize}{qw/cursor _row_parser _result_inflator/};
# nor is it sensical to store a not-yet-fired-count pager
if ($to_serialize->{pager} and ref $to_serialize->{pager}{total_entries} eq 'CODE') {
}
}
+1;
+
+__END__
+
# XXX: FIXME: Attributes docs need clearing up
=head1 ATTRIBUTES
=over 4
-=item Value: \@columns
+=item Value: \@columns | \%columns | $column
=back
expression). Adds C<me.> onto the start of any column without a C<.> in
it and sets C<select> from that, then auto-populates C<as> from
C<select> as normal. (You may also use the C<cols> attribute, as in
- earlier versions of DBIC.)
+ earlier versions of DBIC, but this is deprecated.)
Essentially C<columns> does the same as L</select> and L</as>.
=back
- Indicates additional columns to be selected from storage. Works the same
- as L</columns> but adds columns to the selection. (You may also use the
- C<include_columns> attribute, as in earlier versions of DBIC). For
- example:-
+ Indicates additional columns to be selected from storage. Works the same as
+ L</columns> but adds columns to the selection. (You may also use the
+ C<include_columns> attribute, as in earlier versions of DBIC, but this is
+ deprecated). For example:-
$schema->resultset('CD')->search(undef, {
'+columns' => ['artist.name'],
=back
-=head2 +as
-
-=over 4
-
-Indicates additional column names for those added via L</+select>. See L</as>.
-
-=back
-
=head2 as
=over 4
You can create your own accessors if required - see
L<DBIx::Class::Manual::Cookbook> for details.
+=head2 +as
+
+=over 4
+
+Indicates additional column names for those added via L</+select>. See L</as>.
+
+=back
+
=head2 join
=over 4
will return a set of all artists that have both a cd with title 'Down
to Earth' and a cd with title 'Popular'.
-If you want to fetch related objects from other tables as well, see C<prefetch>
+If you want to fetch related objects from other tables as well, see L</prefetch>
below.
NOTE: An internal join-chain pruner will discard certain joins while
For more help on using joins with search, see L<DBIx::Class::Manual::Joining>.
-=head2 prefetch
+=head2 collapse
=over 4
-=item Value: ($rel_name | \@rel_names | \%rel_names)
+=item Value: (0 | 1)
=back
-Contains one or more relationships that should be fetched along with
-the main query (when they are accessed afterwards the data will
-already be available, without extra queries to the database). This is
-useful for when you know you will need the related objects, because it
-saves at least one query:
-
- my $rs = $schema->resultset('Tag')->search(
- undef,
- {
- prefetch => {
- cd => 'artist'
- }
- }
- );
-
-The initial search results in SQL like the following:
-
- SELECT tag.*, cd.*, artist.* FROM tag
- JOIN cd ON tag.cd = cd.cdid
- JOIN artist ON cd.artist = artist.artistid
-
-L<DBIx::Class> has no need to go back to the database when we access the
-C<cd> or C<artist> relationships, which saves us two SQL statements in this
-case.
-
-Simple prefetches will be joined automatically, so there is no need
-for a C<join> attribute in the above search.
-
-L</prefetch> can be used with the any of the relationship types and
-multiple prefetches can be specified together. Below is a more complex
-example that prefetches a CD's artist, its liner notes (if present),
-the cover image, the tracks on that cd, and the guests on those
-tracks.
-
- # Assuming:
- My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
- My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
- My::Schema::CD->has_one( cover_image => 'My::Schema::Artwork' );
- My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
-
- My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
-
- My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
-
-
- my $rs = $schema->resultset('CD')->search(
- undef,
- {
- prefetch => [
- { artist => 'record_label'}, # belongs_to => belongs_to
- 'liner_note', # might_have
- 'cover_image', # has_one
- { tracks => 'guests' }, # has_many => has_many
- ]
- }
- );
-
-This will produce SQL like the following:
-
- SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
- tracks.*, guests.*
- FROM cd me
- JOIN artist artist
- ON artist.artistid = me.artistid
- JOIN record_label record_label
- ON record_label.labelid = artist.labelid
- LEFT JOIN track tracks
- ON tracks.cdid = me.cdid
- LEFT JOIN guest guests
- ON guests.trackid = track.trackid
- LEFT JOIN liner_notes liner_note
- ON liner_note.cdid = me.cdid
- JOIN cd_artwork cover_image
- ON cover_image.cdid = me.cdid
- ORDER BY tracks.cd
-
-Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
-C<tracks>, and C<guests> of the CD will all be available through the
-relationship accessors without the need for additional queries to the
-database.
-
-However, there is one caveat to be observed: it can be dangerous to
-prefetch more than one L<has_many|DBIx::Class::Relationship/has_many>
-relationship on a given level. e.g.:
-
- my $rs = $schema->resultset('CD')->search(
- undef,
- {
- prefetch => [
- 'tracks', # has_many
- { cd_to_producer => 'producer' }, # has_many => belongs_to (i.e. m2m)
- ]
- }
- );
-
-The collapser currently can't identify duplicate tuples for multiple
-L<has_many|DBIx::Class::Relationship/has_many> relationships and as a
-result the second L<has_many|DBIx::Class::Relationship/has_many>
-relation could contain redundant objects.
+When set to a true value, indicates that any rows fetched from joined has_many
+relationships are to be aggregated into the corresponding "parent" object. For
+example, the resultset:
-=head3 Using L</prefetch> with L</join>
+ my $rs = $schema->resultset('CD')->search({}, {
+ '+columns' => [ qw/ tracks.title tracks.position / ],
+ join => 'tracks',
+ collapse => 1,
+ });
-L</prefetch> implies a L</join> with the equivalent argument, and is
-properly merged with any existing L</join> specification. So the
-following:
+While executing the following query:
- my $rs = $schema->resultset('CD')->search(
- {'record_label.name' => 'Music Product Ltd.'},
- {
- join => {artist => 'record_label'},
- prefetch => 'artist',
- }
- );
+ SELECT me.*, tracks.title, tracks.position
+ FROM cd me
+ LEFT JOIN track tracks
+ ON tracks.cdid = me.cdid
-... will work, searching on the record label's name, but only
-prefetching the C<artist>.
+Will return only as many objects as there are rows in the CD source, even
+though the result of the query may span many rows. Each of these CD objects
+will in turn have multiple "Track" objects hidden behind the has_many
+generated accessor C<tracks>. Without C<< collapse => 1 >>, the return values
+of this resultset would be as many CD objects as there are tracks (a "Cartesian
+product"), with each CD object containing exactly one of all fetched Track data.
-=head3 Using L</prefetch> with L</select> / L</+select> / L</as> / L</+as>
+When a collapse is requested on a non-ordered resultset, an order by some
+unique part of the main source (the left-most table) is inserted automatically.
+This is done so that the resultset is allowed to be "lazy" - calling
+L<< $rs->next|/next >> will fetch only as many rows as it needs to build the next
+object with all of its related data.
-L</prefetch> implies a L</+select>/L</+as> with the fields of the
-prefetched relations. So given:
+If an L</order_by> is already declared, and orders the resultset in a way that
+makes collapsing as described above impossible (e.g. C<< ORDER BY
+has_many_rel.column >> or C<ORDER BY RANDOM()>), DBIC will automatically
+switch to "eager" mode and slurp the entire resultset before consturcting the
+first object returned by L</next>.
- my $rs = $schema->resultset('CD')->search(
- undef,
- {
- select => ['cd.title'],
- as => ['cd_title'],
- prefetch => 'artist',
- }
- );
+Setting this attribute on a resultset that does not join any has_many
+relations is a no-op.
-The L</select> becomes: C<'cd.title', 'artist.*'> and the L</as>
-becomes: C<'cd_title', 'artist.*'>.
-
-=head3 CAVEATS
+For a more in-depth discussion, see L</PREFETCHING>.
-Prefetch does a lot of deep magic. As such, it may not behave exactly
-as you might expect.
+=head2 prefetch
=over 4
-=item *
-
-Prefetch uses the L</cache> to populate the prefetched relationships. This
-may or may not be what you want.
+=item Value: ($rel_name | \@rel_names | \%rel_names)
-=item *
+=back
-If you specify a condition on a prefetched relationship, ONLY those
-rows that match the prefetched condition will be fetched into that relationship.
-This means that adding prefetch to a search() B<may alter> what is returned by
-traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
+This attribute is a shorthand for specifying a L</join> spec, adding all
+columns from the joined related sources as L</+columns> and setting
+L</collapse> to a true value. For example, the following two queries are
+equivalent:
- my $artist_rs = $schema->resultset('Artist')->search({
- 'cds.year' => 2008,
- }, {
- join => 'cds',
+ my $rs = $schema->resultset('Artist')->search({}, {
+ prefetch => { cds => ['genre', 'tracks' ] },
});
- my $count = $artist_rs->first->cds->count;
+and
- my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
+ my $rs = $schema->resultset('Artist')->search({}, {
+ join => { cds => ['genre', 'tracks' ] },
+ collapse => 1,
+ '+columns' => [
+ (map
+ { +{ "cds.$_" => "cds.$_" } }
+ $schema->source('Artist')->related_source('cds')->columns
+ ),
+ (map
+ { +{ "cds.genre.$_" => "genre.$_" } }
+ $schema->source('Artist')->related_source('cds')->related_source('genre')->columns
+ ),
+ (map
+ { +{ "cds.tracks.$_" => "tracks.$_" } }
+ $schema->source('Artist')->related_source('cds')->related_source('tracks')->columns
+ ),
+ ],
+ });
- my $prefetch_count = $artist_rs_prefetch->first->cds->count;
+Both producing the following SQL:
+
+ SELECT me.artistid, me.name, me.rank, me.charfield,
+ cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track,
+ genre.genreid, genre.name,
+ tracks.trackid, tracks.cd, tracks.position, tracks.title, tracks.last_updated_on, tracks.last_updated_at
+ FROM artist me
+ LEFT JOIN cd cds
+ ON cds.artist = me.artistid
+ LEFT JOIN genre genre
+ ON genre.genreid = cds.genreid
+ LEFT JOIN track tracks
+ ON tracks.cd = cds.cdid
+ ORDER BY me.artistid
+
+While L</prefetch> implies a L</join>, it is ok to mix the two together, as
+the arguments are properly merged and generally do the right thing. For
+example, you may want to do the following:
+
+ my $artists_and_cds_without_genre = $schema->resultset('Artist')->search(
+ { 'genre.genreid' => undef },
+ {
+ join => { cds => 'genre' },
+ prefetch => 'cds',
+ }
+ );
- cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
+Which generates the following SQL:
-that cmp_ok() may or may not pass depending on the datasets involved. This
-behavior may or may not survive the 0.09 transition.
+ SELECT me.artistid, me.name, me.rank, me.charfield,
+ cds.cdid, cds.artist, cds.title, cds.year, cds.genreid, cds.single_track
+ FROM artist me
+ LEFT JOIN cd cds
+ ON cds.artist = me.artistid
+ LEFT JOIN genre genre
+ ON genre.genreid = cds.genreid
+ WHERE genre.genreid IS NULL
+ ORDER BY me.artistid
-=back
+For a more in-depth discussion, see L</PREFETCHING>.
=head2 alias
... FOR SHARED. If \$scalar is passed, this is taken directly and embedded in the
query.
+=head1 PREFETCHING
+
+DBIx::Class supports arbitrary related data prefetching from multiple related
+sources. Any combination of relationship types and column sets are supported.
+If L<collapsing|/collapse> is requested, there is an additional requirement of
+selecting enough data to make every individual object uniquely identifiable.
+
+Here are some more involved examples, based on the following relationship map:
+
+ # Assuming:
+ My::Schema::CD->belongs_to( artist => 'My::Schema::Artist' );
+ My::Schema::CD->might_have( liner_note => 'My::Schema::LinerNotes' );
+ My::Schema::CD->has_many( tracks => 'My::Schema::Track' );
+
+ My::Schema::Artist->belongs_to( record_label => 'My::Schema::RecordLabel' );
+
+ My::Schema::Track->has_many( guests => 'My::Schema::Guest' );
+
+
+
+ my $rs = $schema->resultset('Tag')->search(
+ undef,
+ {
+ prefetch => {
+ cd => 'artist'
+ }
+ }
+ );
+
+The initial search results in SQL like the following:
+
+ SELECT tag.*, cd.*, artist.* FROM tag
+ JOIN cd ON tag.cd = cd.cdid
+ JOIN artist ON cd.artist = artist.artistid
+
+L<DBIx::Class> has no need to go back to the database when we access the
+C<cd> or C<artist> relationships, which saves us two SQL statements in this
+case.
+
+Simple prefetches will be joined automatically, so there is no need
+for a C<join> attribute in the above search.
+
+The L</prefetch> attribute can be used with any of the relationship types
+and multiple prefetches can be specified together. Below is a more complex
+example that prefetches a CD's artist, its liner notes (if present),
+the cover image, the tracks on that CD, and the guests on those
+tracks.
+
+ my $rs = $schema->resultset('CD')->search(
+ undef,
+ {
+ prefetch => [
+ { artist => 'record_label'}, # belongs_to => belongs_to
+ 'liner_note', # might_have
+ 'cover_image', # has_one
+ { tracks => 'guests' }, # has_many => has_many
+ ]
+ }
+ );
+
+This will produce SQL like the following:
+
+ SELECT cd.*, artist.*, record_label.*, liner_note.*, cover_image.*,
+ tracks.*, guests.*
+ FROM cd me
+ JOIN artist artist
+ ON artist.artistid = me.artistid
+ JOIN record_label record_label
+ ON record_label.labelid = artist.labelid
+ LEFT JOIN track tracks
+ ON tracks.cdid = me.cdid
+ LEFT JOIN guest guests
+ ON guests.trackid = track.trackid
+ LEFT JOIN liner_notes liner_note
+ ON liner_note.cdid = me.cdid
+ JOIN cd_artwork cover_image
+ ON cover_image.cdid = me.cdid
+ ORDER BY tracks.cd
+
+Now the C<artist>, C<record_label>, C<liner_note>, C<cover_image>,
+C<tracks>, and C<guests> of the CD will all be available through the
+relationship accessors without the need for additional queries to the
+database.
+
+=head3 CAVEATS
+
+Prefetch does a lot of deep magic. As such, it may not behave exactly
+as you might expect.
+
+=over 4
+
+=item *
+
+Prefetch uses the L</cache> to populate the prefetched relationships. This
+may or may not be what you want.
+
+=item *
+
+If you specify a condition on a prefetched relationship, ONLY those
+rows that match the prefetched condition will be fetched into that relationship.
+This means that adding prefetch to a search() B<may alter> what is returned by
+traversing a relationship. So, if you have C<< Artist->has_many(CDs) >> and you do
+
+ my $artist_rs = $schema->resultset('Artist')->search({
+ 'cds.year' => 2008,
+ }, {
+ join => 'cds',
+ });
+
+ my $count = $artist_rs->first->cds->count;
+
+ my $artist_rs_prefetch = $artist_rs->search( {}, { prefetch => 'cds' } );
+
+ my $prefetch_count = $artist_rs_prefetch->first->cds->count;
+
+ cmp_ok( $count, '==', $prefetch_count, "Counts should be the same" );
+
+That cmp_ok() may or may not pass depending on the datasets involved. In other
+words the C<WHERE> condition would apply to the entire dataset, just like
+it would in regular SQL. If you want to add a condition only to the "right side"
+of a C<LEFT JOIN> - consider declaring and using a L<relationship with a custom
+condition|DBIx::Class::Relationship::Base/condition>
+
+=back
+
=head1 DBIC BIND VALUES
Because DBIC may need more information to bind values than just the column name
You may distribute this code under the same terms as Perl itself.
-=cut
-
-1;
$new->_sql_maker_opts({});
$new->_dbh_details({});
$new->{_in_do_block} = 0;
- $new->{_dbh_gen} = 0;
# read below to see what this does
$new->_arm_global_destructor;
# soon as possible (DBIC will reconnect only on demand from within
# the thread)
my @instances = grep { defined $_ } values %seek_and_destroy;
+ %seek_and_destroy = ();
+
for (@instances) {
- $_->{_dbh_gen}++; # so that existing cursors will drop as well
$_->_dbh(undef);
$_->transaction_depth(0);
$_->savepoints([]);
- }
- # properly renumber all existing refs
- %seek_and_destroy = ();
- $_->_arm_global_destructor for @instances;
+ # properly renumber existing refs
+ $_->_arm_global_destructor
+ }
}
}
my $pid = $self->_conn_pid;
if( defined $pid and $pid != $$ and my $dbh = $self->_dbh ) {
$dbh->{InactiveDestroy} = 1;
- $self->{_dbh_gen}++;
$self->_dbh(undef);
$self->transaction_depth(0);
$self->savepoints([]);
%{ $self->_dbh->{CachedKids} } = ();
$self->_dbh->disconnect;
$self->_dbh(undef);
- $self->{_dbh_gen}++;
}
}
my ($sql, $bind) = $self->_prep_for_execute($op, $ident, \@args);
- shift->dbh_do( # retry over disconnects
- '_dbh_execute',
- shift->dbh_do( _dbh_execute => # retry over disconnects
++ # not even a PID check - we do not care about the state of the _dbh.
++ # All we need is to get the appropriate drivers loaded if they aren't
++ # already so that the assumption in ad7c50fc26e holds
++ $self->_populate_dbh unless $self->_dbh;
++
++ $self->dbh_do( _dbh_execute => # retry over disconnects
$sql,
$bind,
- $ident,
+ $self->_dbi_attrs_for_bind($ident, $bind),
);
}
sub _dbh_execute {
- my ($self, undef, $sql, $bind, $ident) = @_;
+ my ($self, $dbh, $sql, $bind, $bind_attrs) = @_;
$self->_query_start( $sql, $bind );
- my $bind_attrs = $self->_dbi_attrs_for_bind($ident, $bind);
+ my $sth = $self->_bind_sth_params(
+ $self->_prepare_sth($dbh, $sql),
+ $bind,
+ $bind_attrs,
+ );
+
+ # Can this fail without throwing an exception anyways???
+ my $rv = $sth->execute();
+ $self->throw_exception(
+ $sth->errstr || $sth->err || 'Unknown error: execute() returned false, but error flags were not set...'
+ ) if !$rv;
+
+ $self->_query_end( $sql, $bind );
+
+ return (wantarray ? ($rv, $sth, @$bind) : $rv);
+ }
+
+ sub _prepare_sth {
+ my ($self, $dbh, $sql) = @_;
+
+ # 3 is the if_active parameter which avoids active sth re-use
+ my $sth = $self->disable_sth_caching
+ ? $dbh->prepare($sql)
+ : $dbh->prepare_cached($sql, {}, 3);
+
+ # XXX You would think RaiseError would make this impossible,
+ # but apparently that's not true :(
+ $self->throw_exception(
+ $dbh->errstr
+ ||
+ sprintf( "\$dbh->prepare() of '%s' through %s failed *silently* without "
+ .'an exception and/or setting $dbh->errstr',
+ length ($sql) > 20
+ ? substr($sql, 0, 20) . '...'
+ : $sql
+ ,
+ 'DBD::' . $dbh->{Driver}{Name},
+ )
+ ) if !$sth;
+
+ $sth;
+ }
- my $sth = $self->_sth($sql);
+ sub _bind_sth_params {
+ my ($self, $sth, $bind, $bind_attrs) = @_;
for my $i (0 .. $#$bind) {
if (ref $bind->[$i][1] eq 'SCALAR') { # any scalarrefs are assumed to be bind_inouts
);
}
else {
+ # FIXME SUBOPTIMAL - most likely this is not necessary at all
+ # confirm with dbi-dev whether explicit stringification is needed
+ my $v = ( length ref $bind->[$i][1] and overload::Method($bind->[$i][1], '""') )
+ ? "$bind->[$i][1]"
+ : $bind->[$i][1]
+ ;
$sth->bind_param(
$i + 1,
- (ref $bind->[$i][1] and overload::Method($bind->[$i][1], '""'))
- ? "$bind->[$i][1]"
- : $bind->[$i][1]
- ,
+ $v,
$bind_attrs->[$i],
);
}
}
- # Can this fail without throwing an exception anyways???
- my $rv = $sth->execute();
- $self->throw_exception(
- $sth->errstr || $sth->err || 'Unknown error: execute() returned false, but error flags were not set...'
- ) if !$rv;
-
- $self->_query_end( $sql, $bind );
-
- return (wantarray ? ($rv, $sth, @$bind) : $rv);
+ $sth;
}
sub _prefetch_autovalues {
my @col_range = (0..$#$cols);
- # FIXME - perhaps this is not even needed? does DBI stringify?
+ # FIXME SUBOPTIMAL - most likely this is not necessary at all
+ # confirm with dbi-dev whether explicit stringification is needed
#
# forcibly stringify whatever is stringifiable
# ResultSet::populate() hands us a copy - safe to mangle
for my $r (0 .. $#$data) {
for my $c (0 .. $#{$data->[$r]}) {
$data->[$r][$c] = "$data->[$r][$c]"
- if ( ref $data->[$r][$c] and overload::Method($data->[$r][$c], '""') );
+ if ( length ref $data->[$r][$c] and overload::Method($data->[$r][$c], '""') );
}
}
my $guard = $self->txn_scope_guard;
$self->_query_start( $sql, @$proto_bind ? [[undef => '__BULK_INSERT__' ]] : () );
- my $sth = $self->_sth($sql);
+ my $sth = $self->_prepare_sth($self->_dbh, $sql);
my $rv = do {
if (@$proto_bind) {
# proto bind contains the information on which pieces of $data to pull
$self->_select_args(@_);
# my ($sql, $prepared_bind) = $self->_gen_sql_bind($op, $ident, [ $select, $cond, $rs_attrs, $rows, $offset ]);
- my ($sql, $prepared_bind) = $self->_gen_sql_bind($op, $ident, \@args);
- $prepared_bind ||= [];
+ my ($sql, $bind) = $self->_gen_sql_bind($op, $ident, \@args);
- return wantarray
- ? ($sql, $prepared_bind)
- : \[ "($sql)", @$prepared_bind ]
- ;
+ # reuse the bind arrayref
+ unshift @{$bind}, "($sql)";
+ \$bind;
}
sub _select_args {
$attrs->{rows} = $sql_maker->__max_int;
}
- my @limit;
+ my ($complex_prefetch, @limit);
- # see if we need to tear the prefetch apart otherwise delegate the limiting to the
- # storage, unless software limit was requested
+ # see if we will need to tear the prefetch apart to satisfy group_by == select
+ # this is *extremely tricky* to get right
+ #
+ # Follows heavy but necessary analyzis of the group_by - if it refers to any
+ # sort of non-root column assume the user knows what they are doing and do
+ # not try to be clever
if (
- #limited has_many
- ( $attrs->{rows} && keys %{$attrs->{collapse}} )
- ||
- # grouped prefetch (to satisfy group_by == select)
- ( $attrs->{group_by}
- &&
- @{$attrs->{group_by}}
- &&
- $attrs->{_prefetch_selector_range}
- )
+ $attrs->{_related_results_construction}
+ and
+ $attrs->{group_by}
+ and
+ @{$attrs->{group_by}}
+ and
+ my $grp_aliases = try {
+ $self->_resolve_aliastypes_from_select_args( $attrs->{from}, undef, undef, { group_by => $attrs->{group_by} } )
+ }
) {
- ($ident, $select, $where, $attrs)
- = $self->_adjust_select_args_for_complex_prefetch ($ident, $select, $where, $attrs);
+ $complex_prefetch = ! defined first { $_ ne $rs_alias } keys %{ $grp_aliases->{grouping} || {} };
+ }
+
+ $complex_prefetch ||= ( $attrs->{rows} && $attrs->{collapse} );
+
+ if ($complex_prefetch) {
+ ($ident, $select, $where, $attrs) =
+ $self->_adjust_select_args_for_complex_prefetch ($ident, $select, $where, $attrs);
}
elsif (! $attrs->{software_limit} ) {
push @limit, (
# try to simplify the joinmap further (prune unreferenced type-single joins)
if (
+ ! $complex_prefetch
+ and
ref $ident
and
reftype $ident eq 'ARRAY'
=cut
- sub _dbh_sth {
- my ($self, $dbh, $sql) = @_;
-
- # 3 is the if_active parameter which avoids active sth re-use
- my $sth = $self->disable_sth_caching
- ? $dbh->prepare($sql)
- : $dbh->prepare_cached($sql, {}, 3);
-
- # XXX You would think RaiseError would make this impossible,
- # but apparently that's not true :(
- $self->throw_exception(
- $dbh->errstr
- ||
- sprintf( "\$dbh->prepare() of '%s' through %s failed *silently* without "
- .'an exception and/or setting $dbh->errstr',
- length ($sql) > 20
- ? substr($sql, 0, 20) . '...'
- : $sql
- ,
- 'DBD::' . $dbh->{Driver}{Name},
- )
- ) if !$sth;
-
- $sth;
- }
-
- sub sth {
- carp_unique 'sth was mistakenly marked/documented as public, stop calling it (will be removed before DBIC v0.09)';
- shift->_sth(@_);
- }
-
- sub _sth {
- my ($self, $sql) = @_;
- $self->dbh_do('_dbh_sth', $sql); # retry over disconnects
- }
-
sub _dbh_columns_info_for {
my ($self, $dbh, $table) = @_;
See L<SQL::Translator/METHODS> for a list of values for C<\%sqlt_args>.
The most common value for this would be C<< { add_drop_table => 1 } >>
to have the SQL produced include a C<DROP TABLE> statement for each table
- created. For quoting purposes supply C<quote_table_names> and
- C<quote_field_names>.
+ created. For quoting purposes supply C<quote_identifiers>.
If no arguments are passed, then the following default values are assumed:
projects / dbsrgits/DBIx-Class.git / commitdiff