sub _adjust_select_args_for_limited_prefetch {
my ($self, $from, $select, $where, $attrs) = @_;
- if ($attrs->{group_by} and @{$attrs->{group_by}}) {
- $self->throw_exception ('Prefetch with limit (rows/offset) is not supported on resultsets with a group_by attribute');
+ if ($attrs->{group_by} && @{$attrs->{group_by}}) {
+ $self->throw_exception ('has_many prefetch with limit (rows/offset) is not supported on grouped resultsets');
}
- $self->throw_exception ('Prefetch with limit (rows/offset) is not supported on resultsets with a custom from attribute')
+ $self->throw_exception ('has_many prefetch with limit (rows/offset) is not supported on resultsets with a custom from attribute')
if (ref $from ne 'ARRAY');
+
# separate attributes
my $sub_attrs = { %$attrs };
delete $attrs->{$_} for qw/where bind rows offset/;
return $alias2source;
}
+# Takes $ident, \@column_names
+#
+# returns { $column_name => \%column_info, ... }
+# also note: this adds -result_source => $rsrc to the column info
+#
+# usage:
+# my $col_sources = $self->_resolve_column_info($ident, [map $_->[0], @{$bind}]);
+sub _resolve_column_info {
+ my ($self, $ident, $colnames) = @_;
+ my $alias2src = $self->_resolve_ident_sources($ident);
+
+ my $sep = $self->_sql_maker_opts->{name_sep} || '.';
+ $sep = "\Q$sep\E";
-
++
+ my %return;
+ foreach my $col (@{$colnames}) {
+ $col =~ m/^ (?: ([^$sep]+) $sep)? (.+) $/x;
+
+ my $alias = $1 || 'me';
+ my $colname = $2;
+
+ my $rsrc = $alias2src->{$alias};
+ $return{$col} = $rsrc && { %{$rsrc->column_info($colname)}, -result_source => $rsrc };
+ }
+ return \%return;
+}
+
- sub count {
- my ($self, $source, $attrs) = @_;
-
- my $tmp_attrs = { %$attrs };
-
- # take off any limits, record_filter is cdbi, and no point of ordering a count
- delete $tmp_attrs->{$_} for (qw/select as rows offset order_by record_filter/);
-
- # overwrite the selector
- $tmp_attrs->{select} = { count => '*' };
-
- my $tmp_rs = $source->resultset_class->new($source, $tmp_attrs);
- my ($count) = $tmp_rs->cursor->next;
-
- # if the offset/rows attributes are still present, we did not use
- # a subquery, so we need to make the calculations in software
- $count -= $attrs->{offset} if $attrs->{offset};
- $count = $attrs->{rows} if $attrs->{rows} and $attrs->{rows} < $count;
- $count = 0 if ($count < 0);
-
- return $count;
- }
-
- sub count_grouped {
- my ($self, $source, $attrs) = @_;
-
- # copy for the subquery, we need to do some adjustments to it too
- my $sub_attrs = { %$attrs };
-
- # these can not go in the subquery, and there is no point of ordering it
- delete $sub_attrs->{$_} for qw/collapse select as order_by/;
-
- # if we prefetch, we group_by primary keys only as this is what we would get out of the rs via ->next/->all
- # simply deleting group_by suffices, as the code below will re-fill it
- # Note: we check $attrs, as $sub_attrs has collapse deleted
- if (ref $attrs->{collapse} and keys %{$attrs->{collapse}} ) {
- delete $sub_attrs->{group_by};
- }
-
- $sub_attrs->{group_by} ||= [ map { "$attrs->{alias}.$_" } ($source->primary_columns) ];
- $sub_attrs->{select} = $self->_grouped_count_select ($source, $sub_attrs);
-
- $attrs->{from} = [{
- count_subq => $source->resultset_class->new ($source, $sub_attrs )->as_query
- }];
-
- # the subquery replaces this
- delete $attrs->{$_} for qw/where bind collapse group_by having having_bind rows offset/;
-
- return $self->count ($source, $attrs);
+ # Returns a counting SELECT for a simple count
+ # query. Abstracted so that a storage could override
+ # this to { count => 'firstcol' } or whatever makes
+ # sense as a performance optimization
+ sub _count_select {
+ #my ($self, $source, $rs_attrs) = @_;
+ return { count => '*' };
}
+ # Returns a SELECT which will end up in the subselect
+ # There may or may not be a group_by, as the subquery
+ # might have been called to accomodate a limit
#
- # Returns a SELECT to go with a supplied GROUP BY
- # (caled by count_grouped so a group_by is present)
- # Most databases expect them to match, but some
- # choke in various ways.
+ # Most databases would be happy with whatever ends up
+ # here, but some choke in various ways.
#
- sub _grouped_count_select {
- my ($self, $source, $rs_args) = @_;
- return $rs_args->{group_by};
+ sub _subq_count_select {
+ my ($self, $source, $rs_attrs) = @_;
+ return $rs_attrs->{group_by} if $rs_attrs->{group_by};
+
+ my @pcols = map { join '.', $rs_attrs->{alias}, $_ } ($source->primary_columns);
+ return @pcols ? \@pcols : [ 1 ];
}
+
sub source_bind_attributes {
my ($self, $source) = @_;
projects / dbsrgits/DBIx-Class.git / commitdiff