my ($self, $from, $select, $where, $attrs) = @_;
$self->throw_exception ('Nothing to prefetch... how did we get here?!')
- if not @{$attrs->{_prefetch_select}};
+ if not @{$attrs->{_prefetch_selector_range}};
$self->throw_exception ('Complex prefetches are not supported on resultsets with a custom from attribute')
if (ref $from ne 'ARRAY' || ref $from->[0] ne 'HASH' || ref $from->[1] ne 'ARRAY');
delete $outer_attrs->{$_} for qw/where bind rows offset group_by having/;
my $inner_attrs = { %$attrs };
- delete $inner_attrs->{$_} for qw/for collapse _prefetch_select _collapse_order_by select as/;
+ delete $inner_attrs->{$_} for qw/for collapse _prefetch_selector_range _collapse_order_by select as/;
# bring over all non-collapse-induced order_by into the inner query (if any)
# on the outside we substitute any function for its alias
my $outer_select = [ @$select ];
my $inner_select = [];
- for my $i (0 .. ( @$outer_select - @{$outer_attrs->{_prefetch_select}} - 1) ) {
+
+ my ($p_start, $p_end) = @{$outer_attrs->{_prefetch_selector_range}};
+ for my $i (0 .. $p_start - 1, $p_end + 1 .. $#$outer_select) {
my $sel = $outer_select->[$i];
if (ref $sel eq 'HASH' ) {
group_by => ['dummy'], %$inner_attrs,
});
- # if a multi-type join was needed in the subquery - add a group_by to simulate the
- # collapse in the subq
- $inner_attrs->{group_by} ||= $inner_select
- if first { ! $_->[0]{-is_single} } (@{$inner_from}[1 .. $#$inner_from]);
+ my $inner_aliastypes =
+ $self->_resolve_aliastypes_from_select_args( $inner_from, $inner_select, $where, $inner_attrs );
+
+ # if a multi-type non-selecting (only restricting) join was needed in the subquery
+ # add a group_by to simulate the collapse in the subq
+ if (
+ ! $inner_attrs->{group_by}
+ and
+ first {
+ $inner_aliastypes->{restricting}{$_}
+ and
+ ! $inner_aliastypes->{selecting}{$_}
+ } ( keys %{$inner_aliastypes->{multiplying}||{}} )
+ ) {
+ my $unprocessed_order_chunks;
+ ($inner_attrs->{group_by}, $unprocessed_order_chunks) = $self->_group_over_selection (
+ $inner_from, $inner_select, $inner_attrs->{order_by}
+ );
+
+ $self->throw_exception (
+ 'A required group_by clause could not be constructed automatically due to a complex '
+ . 'order_by criteria. Either order_by columns only (no functions) or construct a suitable '
+ . 'group_by by hand'
+ ) if $unprocessed_order_chunks;
+ }
# we already optimized $inner_from above
local $self->{_use_join_optimizer} = 0;
+{
-alias => $attrs->{alias},
- -source_handle => $inner_from->[0]{-source_handle},
+ -rsrc => $inner_from->[0]{-rsrc},
$attrs->{alias} => $subq,
};
};
# also throw in a group_by if restricting to guard against
# cross-join explosions
#
+ my $need_outer_group_by;
while (my $j = shift @$from) {
my $alias = $j->[0]{-alias};
}
elsif ($outer_aliastypes->{restricting}{$alias}) {
push @outer_from, $j;
- $outer_attrs->{group_by} ||= $outer_select unless $j->[0]{-is_single};
+ $need_outer_group_by ||= ! $j->[0]{-is_single};
}
}
# demote the outer_from head
$outer_from[0] = $outer_from[0][0];
+ if ($need_outer_group_by and ! $outer_attrs->{group_by}) {
+
+ my $unprocessed_order_chunks;
+ ($outer_attrs->{group_by}, $unprocessed_order_chunks) = $self->_group_over_selection (
+ \@outer_from, $outer_select, $outer_attrs->{order_by}
+ );
+
+ $self->throw_exception (
+ 'A required group_by clause could not be constructed automatically due to a complex '
+ . 'order_by criteria. Either order_by columns only (no functions) or construct a suitable '
+ . 'group_by by hand'
+ ) if $unprocessed_order_chunks;
+
+ }
+
# This is totally horrific - the $where ends up in both the inner and outer query
# Unfortunately not much can be done until SQLA2 introspection arrives, and even
# then if where conditions apply to the *right* side of the prefetch, you may have
# set up a botched SQLA
my $sql_maker = $self->sql_maker;
- local $sql_maker->{having_bind}; # these are throw away results
+ # these are throw away results, do not pollute the bind stack
+ local $sql_maker->{select_bind};
+ local $sql_maker->{where_bind};
+ local $sql_maker->{group_bind};
+ local $sql_maker->{having_bind};
# we can't scan properly without any quoting (\b doesn't cut it
# everywhere), so unless there is proper quoting set - use our
local $sql_maker->{name_sep} = $sql_maker->{name_sep};
unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) {
- $sql_maker->{quote_char} = "\x00";
+ $sql_maker->{quote_char} = ["\x00", "\xFF"];
+ # if we don't unset it we screw up retarded but unfortunately working
+ # 'MAX(foo.bar)' => { '>', 3 }
$sql_maker->{name_sep} = '';
}
}),
],
selecting => [
- $self->_extract_order_columns ($attrs->{order_by}, $sql_maker),
$sql_maker->_recurse_fields ($select),
+ ( map { $_->[0] } $self->_extract_order_criteria ($attrs->{order_by}, $sql_maker) ),
],
};
return $aliases_by_type;
}
+# This is the engine behind { distinct => 1 }
+sub _group_over_selection {
+ my ($self, $from, $select, $order_by) = @_;
+
+ my $rs_column_list = $self->_resolve_column_info ($from);
+
+ my (@group_by, %group_index);
+
+ # the logic is: if it is a { func => val } we assume an aggregate,
+ # otherwise if \'...' or \[...] we assume the user knows what is
+ # going on thus group over it
+ for (@$select) {
+ if (! ref($_) or ref ($_) ne 'HASH' ) {
+ push @group_by, $_;
+ $group_index{$_}++;
+ if ($rs_column_list->{$_} and $_ !~ /\./ ) {
+ # add a fully qualified version as well
+ $group_index{"$rs_column_list->{$_}{-source_alias}.$_"}++;
+ }
+ }
+ }
+
+ # add any order_by parts that are not already present in the group_by
+ # we need to be careful not to add any named functions/aggregates
+ # i.e. order_by => [ ... { count => 'foo' } ... ]
+ my @leftovers;
+ for ($self->_extract_order_criteria($order_by)) {
+ # only consider real columns (for functions the user got to do an explicit group_by)
+ if (@$_ != 1) {
+ push @leftovers, $_;
+ next;
+ }
+ my $chunk = $_->[0];
+ my $colinfo = $rs_column_list->{$chunk} or do {
+ push @leftovers, $_;
+ next;
+ };
+
+ $chunk = "$colinfo->{-source_alias}.$chunk" if $chunk !~ /\./;
+ push @group_by, $chunk unless $group_index{$chunk}++;
+ }
+
+ return wantarray
+ ? (\@group_by, (@leftovers ? \@leftovers : undef) )
+ : \@group_by
+ ;
+}
+
sub _resolve_ident_sources {
my ($self, $ident) = @_;
$tabinfo = $_->[0];
}
- $alias2source->{$tabinfo->{-alias}} = $tabinfo->{-source_handle}->resolve
- if ($tabinfo->{-source_handle});
+ $alias2source->{$tabinfo->{-alias}} = $tabinfo->{-rsrc}
+ if ($tabinfo->{-rsrc});
}
}
my ($self, $ident, $colnames) = @_;
my ($alias2src, $root_alias) = $self->_resolve_ident_sources($ident);
- my (%return, %seen_cols, @auto_colnames);
+ my (%seen_cols, @auto_colnames);
# compile a global list of column names, to be able to properly
# disambiguate unqualified column names (if at all possible)
grep { @{$seen_cols{$_}} == 1 } (keys %seen_cols),
];
- COLUMN:
+ my (%return, $colinfos);
foreach my $col (@$colnames) {
- my ($alias, $colname) = $col =~ m/^ (?: ([^\.]+) \. )? (.+) $/x;
+ my ($source_alias, $colname) = $col =~ m/^ (?: ([^\.]+) \. )? (.+) $/x;
- unless ($alias) {
- # see if the column was seen exactly once (so we know which rsrc it came from)
- if ($seen_cols{$colname} and @{$seen_cols{$colname}} == 1) {
- $alias = $seen_cols{$colname}[0];
- }
- else {
- next COLUMN;
- }
- }
+ # if the column was seen exactly once - we know which rsrc it came from
+ $source_alias ||= $seen_cols{$colname}[0]
+ if ($seen_cols{$colname} and @{$seen_cols{$colname}} == 1);
- my $rsrc = $alias2src->{$alias};
- $return{$col} = $rsrc && {
- %{$rsrc->column_info($colname)},
+ next unless $source_alias;
+
+ my $rsrc = $alias2src->{$source_alias}
+ or next;
+
+ $return{$col} = {
+ %{ ( $colinfos->{$source_alias} ||= $rsrc->columns_info )->{$colname} },
-result_source => $rsrc,
- -source_alias => $alias,
+ -source_alias => $source_alias,
};
}
# at all. What this code tries to do (badly) is introspect the condition
# and remove all column qualifiers. If it bails out early (returns undef)
# the calling code should try another approach (e.g. a subquery)
+
+sub _strip_cond_qualifiers_from_array {
+ my ($self, $where) = @_;
+ my @cond;
+ for (my $i = 0; $i < @$where; $i++) {
+ my $entry = $where->[$i];
+ my $hash;
+ my $ref = ref $entry;
+ if ($ref eq 'HASH' or $ref eq 'ARRAY') {
+ $hash = $self->_strip_cond_qualifiers($entry);
+ }
+ elsif (! $ref) {
+ $entry =~ /([^.]+)$/;
+ $hash->{$1} = $where->[++$i];
+ }
+ push @cond, $hash;
+ }
+ return \@cond;
+}
+
sub _strip_cond_qualifiers {
my ($self, $where) = @_;
return $cond unless $where;
if (ref $where eq 'ARRAY') {
- $cond = [
- map {
- my %hash;
- foreach my $key (keys %{$_}) {
- $key =~ /([^.]+)$/;
- $hash{$1} = $_->{$key};
- }
- \%hash;
- } @$where
- ];
+ $cond = $self->_strip_cond_qualifiers_from_array($where);
}
elsif (ref $where eq 'HASH') {
if ( (keys %$where) == 1 && ( (keys %{$where})[0] eq '-and' )) {
- $cond->{-and} = [];
- my @cond = @{$where->{-and}};
- for (my $i = 0; $i < @cond; $i++) {
- my $entry = $cond[$i];
- my $hash;
- my $ref = ref $entry;
- if ($ref eq 'HASH' or $ref eq 'ARRAY') {
- $hash = $self->_strip_cond_qualifiers($entry);
- }
- elsif (! $ref) {
- $entry =~ /([^.]+)$/;
- $hash->{$1} = $cond[++$i];
- }
- else {
- $self->throw_exception ("_strip_cond_qualifiers() is unable to handle a condition reftype $ref");
- }
- push @{$cond->{-and}}, $hash;
- }
+ $cond->{-and} =
+ $self->_strip_cond_qualifiers_from_array($where->{-and});
}
else {
foreach my $key (keys %$where) {
return $cond;
}
-sub _extract_order_columns {
+sub _extract_order_criteria {
my ($self, $order_by, $sql_maker) = @_;
my $parser = sub {
unless wantarray;
my @chunks;
- for my $chunk (map { ref $_ ? @$_ : $_ } ($sql_maker->_order_by_chunks ($order_by) ) ) {
- $chunk =~ s/\s+ (?: ASC|DESC ) \s* $//ix;
+ for ($sql_maker->_order_by_chunks ($order_by) ) {
+ my $chunk = ref $_ ? $_ : [ $_ ];
+ $chunk->[0] =~ s/\s+ (?: ASC|DESC ) \s* $//ix;
push @chunks, $chunk;
}