use List::Util 'first';
use Scalar::Util 'blessed';
-use Sub::Name 'subname';
+use DBIx::Class::_Util qw(UNRESOLVABLE_CONDITION serialize);
+use SQL::Abstract qw(is_plain_value is_literal_value);
+use DBIx::Class::Carp;
use namespace::clean;
#
# {from} specs, aiding the RDBMS query optimizer
#
sub _prune_unused_joins {
- my $self = shift;
- my ($from, $select, $where, $attrs, $ignore_multiplication) = @_;
-
- return $from unless $self->_use_join_optimizer;
+ my ($self, $attrs) = @_;
+
+ # only standard {from} specs are supported, and we could be disabled in general
+ return ($attrs->{from}, {}) unless (
+ ref $attrs->{from} eq 'ARRAY'
+ and
+ @{$attrs->{from}} > 1
+ and
+ ref $attrs->{from}[0] eq 'HASH'
+ and
+ ref $attrs->{from}[1] eq 'ARRAY'
+ and
+ $self->_use_join_optimizer
+ );
- if (ref $from ne 'ARRAY' || ref $from->[0] ne 'HASH' || ref $from->[1] ne 'ARRAY') {
- return $from; # only standard {from} specs are supported
- }
+ my $orig_aliastypes = $self->_resolve_aliastypes_from_select_args($attrs);
- my $aliastypes = $self->_resolve_aliastypes_from_select_args(@_);
+ my $new_aliastypes = { %$orig_aliastypes };
- # don't care
- delete $aliastypes->{joining};
+ # we will be recreating this entirely
+ my @reclassify = 'joining';
# a grouped set will not be affected by amount of rows. Thus any
- # {multiplying} joins can go
- delete $aliastypes->{multiplying}
- if $ignore_multiplication or $attrs->{group_by};
+ # purely multiplicator classifications can go
+ # (will be reintroduced below if needed by something else)
+ push @reclassify, qw(multiplying premultiplied)
+ if $attrs->{_force_prune_multiplying_joins} or $attrs->{group_by};
- my @newfrom = $from->[0]; # FROM head is always present
+ # nuke what will be recalculated
+ delete @{$new_aliastypes}{@reclassify};
- my %need_joins;
+ my @newfrom = $attrs->{from}[0]; # FROM head is always present
- for (values %$aliastypes) {
+ # recalculate what we need once the multipliers are potentially gone
+ # ignore premultiplies, since they do not add any value to anything
+ my %need_joins;
+ for ( @{$new_aliastypes}{grep { $_ ne 'premultiplied' } keys %$new_aliastypes }) {
# add all requested aliases
$need_joins{$_} = 1 for keys %$_;
$need_joins{$_} = 1 for map { values %$_ } map { @{$_->{-parents}} } values %$_;
}
- for my $j (@{$from}[1..$#$from]) {
+ for my $j (@{$attrs->{from}}[1..$#{$attrs->{from}}]) {
push @newfrom, $j if (
- (! $j->[0]{-alias}) # legacy crap
+ (! defined $j->[0]{-alias}) # legacy crap
||
$need_joins{$j->[0]{-alias}}
);
}
- return \@newfrom;
+ # we have a new set of joiners - for everything we nuked pull the classification
+ # off the original stack
+ for my $ctype (@reclassify) {
+ $new_aliastypes->{$ctype} = { map
+ { $need_joins{$_} ? ( $_ => $orig_aliastypes->{$ctype}{$_} ) : () }
+ keys %{$orig_aliastypes->{$ctype}}
+ }
+ }
+
+ return ( \@newfrom, $new_aliastypes );
}
#
# SELECT me.*, other.* FROM ( SELECT me.* FROM ... ) JOIN other ON ...
#
sub _adjust_select_args_for_complex_prefetch {
- my ($self, $from, $select, $where, $attrs) = @_;
-
- $self->throw_exception ('Nothing to prefetch... how did we get here?!')
- if not @{$attrs->{_prefetch_selector_range}||[]};
+ my ($self, $attrs) = @_;
+
+ $self->throw_exception ('Complex prefetches are not supported on resultsets with a custom from attribute') unless (
+ ref $attrs->{from} eq 'ARRAY'
+ and
+ @{$attrs->{from}} > 1
+ and
+ ref $attrs->{from}[0] eq 'HASH'
+ and
+ ref $attrs->{from}[1] eq 'ARRAY'
+ );
- $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');
+ my $root_alias = $attrs->{alias};
# generate inner/outer attribute lists, remove stuff that doesn't apply
my $outer_attrs = { %$attrs };
- delete $outer_attrs->{$_} for qw/where bind rows offset group_by having/;
+ delete @{$outer_attrs}{qw(from bind rows offset group_by _grouped_by_distinct having)};
- my $inner_attrs = { %$attrs };
- delete $inner_attrs->{$_} for qw/for collapse _prefetch_selector_range select as/;
+ my $inner_attrs = { %$attrs, _simple_passthrough_construction => 1 };
+ delete @{$inner_attrs}{qw(for collapse select as)};
- # if the user did not request it, there is no point using it inside
- delete $inner_attrs->{order_by} if delete $inner_attrs->{_order_is_artificial};
+ # there is no point of ordering the insides if there is no limit
+ delete $inner_attrs->{order_by} if (
+ delete $inner_attrs->{_order_is_artificial}
+ or
+ ! $inner_attrs->{rows}
+ );
# generate the inner/outer select lists
# for inside we consider only stuff *not* brought in by the prefetch
# on the outside we substitute any function for its alias
- my $outer_select = [ @$select ];
- my $inner_select;
+ $outer_attrs->{select} = [ @{$attrs->{select}} ];
my ($root_node, $root_node_offset);
- for my $i (0 .. $#$from) {
- my $node = $from->[$i];
+ for my $i (0 .. $#{$inner_attrs->{from}}) {
+ my $node = $inner_attrs->{from}[$i];
my $h = (ref $node eq 'HASH') ? $node
: (ref $node eq 'ARRAY' and ref $node->[0] eq 'HASH') ? $node->[0]
: next
;
- if ( ($h->{-alias}||'') eq $attrs->{alias} and $h->{-rsrc} ) {
+ if ( ($h->{-alias}||'') eq $root_alias and $h->{-rsrc} ) {
$root_node = $h;
$root_node_offset = $i;
last;
unless $root_node;
# use the heavy duty resolver to take care of aliased/nonaliased naming
- my $colinfo = $self->_resolve_column_info($from);
+ my $colinfo = $self->_resolve_column_info($inner_attrs->{from});
my $selected_root_columns;
- my ($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];
+ for my $i (0 .. $#{$outer_attrs->{select}}) {
+ my $sel = $outer_attrs->{select}->[$i];
+
+ next if (
+ $colinfo->{$sel} and $colinfo->{$sel}{-source_alias} ne $root_alias
+ );
if (ref $sel eq 'HASH' ) {
$sel->{-as} ||= $attrs->{as}[$i];
- $outer_select->[$i] = join ('.', $attrs->{alias}, ($sel->{-as} || "inner_column_$i") );
+ $outer_attrs->{select}->[$i] = join ('.', $root_alias, ($sel->{-as} || "inner_column_$i") );
}
elsif (! ref $sel and my $ci = $colinfo->{$sel}) {
$selected_root_columns->{$ci->{-colname}} = 1;
}
- push @$inner_select, $sel;
+ push @{$inner_attrs->{select}}, $sel;
push @{$inner_attrs->{as}}, $attrs->{as}[$i];
}
# We will need to fetch all native columns in the inner subquery, which may
# be a part of an *outer* join condition, or an order_by (which needs to be
- # preserved outside)
+ # preserved outside), or wheres. In other words everything but the inner
+ # selector
# We can not just fetch everything because a potential has_many restricting
# join collapse *will not work* on heavy data types.
- my $connecting_aliastypes = $self->_resolve_aliastypes_from_select_args(
- [grep { ref($_) eq 'ARRAY' or ref($_) eq 'HASH' } @{$from}[$root_node_offset .. $#$from]],
- [],
- $where,
- $inner_attrs
- );
+ my $connecting_aliastypes = $self->_resolve_aliastypes_from_select_args({
+ %$inner_attrs,
+ select => [],
+ });
for (sort map { keys %{$_->{-seen_columns}||{}} } map { values %$_ } values %$connecting_aliastypes) {
my $ci = $colinfo->{$_} or next;
if (
- $ci->{-source_alias} eq $attrs->{alias}
+ $ci->{-source_alias} eq $root_alias
and
! $selected_root_columns->{$ci->{-colname}}++
) {
# adding it to both to keep limits not supporting dark selectors happy
- push @$inner_select, $ci->{-fq_colname};
+ push @{$inner_attrs->{select}}, $ci->{-fq_colname};
push @{$inner_attrs->{as}}, $ci->{-fq_colname};
}
}
- # construct the inner $from and lock it in a subquery
+ # construct the inner {from} and lock it in a subquery
# we need to prune first, because this will determine if we need a group_by below
# throw away all non-selecting, non-restricting multijoins
- # (since we def. do not care about multiplication those inside the subquery)
+ # (since we def. do not care about multiplication of the contents of the subquery)
my $inner_subq = do {
- # must use it here regardless of user requests
+ # must use it here regardless of user requests (vastly gentler on optimizer)
local $self->{_use_join_optimizer} = 1;
# throw away multijoins since we def. do not care about those inside the subquery
- my $inner_from = $self->_prune_unused_joins ($from, $inner_select, $where, $inner_attrs, 'ignore_multiplication');
-
- my $inner_aliastypes =
- $self->_resolve_aliastypes_from_select_args( $inner_from, $inner_select, $where, $inner_attrs );
+ ($inner_attrs->{from}, my $inner_aliastypes) = $self->_prune_unused_joins ({
+ %$inner_attrs, _force_prune_multiplying_joins => 1
+ });
- # we need to simulate collapse in the subq if a multiplying join is pulled
- # by being a non-selecting restrictor
+ # uh-oh a multiplier (which is not us) left in, this is a problem for limits
+ # we will need to add a group_by to collapse the resultset for proper counts
if (
- ! $inner_attrs->{group_by}
+ grep { $_ ne $root_alias } keys %{ $inner_aliastypes->{multiplying} || {} }
and
- first {
- $inner_aliastypes->{restricting}{$_}
- and
- ! $inner_aliastypes->{selecting}{$_}
- } ( keys %{$inner_aliastypes->{multiplying}||{}} )
+ # if there are user-supplied groups - assume user knows wtf they are up to
+ ( ! $inner_aliastypes->{grouping} or $inner_attrs->{_grouped_by_distinct} )
) {
- 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;
+ my $cur_sel = { map { $_ => 1 } @{$inner_attrs->{select}} };
+
+ # *possibly* supplement the main selection with pks if not already
+ # there, as they will have to be a part of the group_by to collapse
+ # things properly
+ my $inner_select_with_extras;
+ my @pks = map { "$root_alias.$_" } $root_node->{-rsrc}->primary_columns
+ or $self->throw_exception( sprintf
+ 'Unable to perform complex limited prefetch off %s without declared primary key',
+ $root_node->{-rsrc}->source_name,
+ );
+ for my $col (@pks) {
+ push @{ $inner_select_with_extras ||= [ @{$inner_attrs->{select}} ] }, $col
+ unless $cur_sel->{$col}++;
+ }
+
+ ($inner_attrs->{group_by}, $inner_attrs->{order_by}) = $self->_group_over_selection({
+ %$inner_attrs,
+ $inner_select_with_extras ? ( select => $inner_select_with_extras ) : (),
+ _aliastypes => $inner_aliastypes,
+ });
}
- # we already optimized $inner_from above
+ # we already optimized $inner_attrs->{from} above
# and already local()ized
$self->{_use_join_optimizer} = 0;
# generate the subquery
$self->_select_args_to_query (
- $inner_from,
- $inner_select,
- $where,
+ @{$inner_attrs}{qw(from select where)},
$inner_attrs,
);
};
# result by tackling yet another group_by to the outside of the query
# work on a shallow copy
- $from = [ @$from ];
+ my @orig_from = @{$attrs->{from}};
- my @outer_from;
+
+ $outer_attrs->{from} = \ my @outer_from;
# we may not be the head
if ($root_node_offset) {
# first generate the outer_from, up to the substitution point
- @outer_from = splice @$from, 0, $root_node_offset;
+ @outer_from = splice @orig_from, 0, $root_node_offset;
+ # substitute the subq at the right spot
push @outer_from, [
{
- -alias => $attrs->{alias},
+ -alias => $root_alias,
-rsrc => $root_node->{-rsrc},
- $attrs->{alias} => $inner_subq,
+ $root_alias => $inner_subq,
},
- @{$from->[0]}[1 .. $#{$from->[0]}],
+ # preserve attrs from what is now the head of the from after the splice
+ @{$orig_from[0]}[1 .. $#{$orig_from[0]}],
];
}
else {
@outer_from = {
- -alias => $attrs->{alias},
+ -alias => $root_alias,
-rsrc => $root_node->{-rsrc},
- $attrs->{alias} => $inner_subq,
+ $root_alias => $inner_subq,
};
}
- shift @$from; # it's replaced in @outer_from already
+ shift @orig_from; # what we just replaced above
# scan the *remaining* from spec against different attributes, and see which joins are needed
# in what role
- my $outer_aliastypes =
- $self->_resolve_aliastypes_from_select_args( $from, $outer_select, $where, $outer_attrs );
+ my $outer_aliastypes = $outer_attrs->{_aliastypes} =
+ $self->_resolve_aliastypes_from_select_args({ %$outer_attrs, from => \@orig_from });
# unroll parents
- my ($outer_select_chain, $outer_restrict_chain) = map { +{
- map { $_ => 1 } map { values %$_} map { @{$_->{-parents}} } values %{ $outer_aliastypes->{$_} }
- } } qw/selecting restricting/;
+ my ($outer_select_chain, @outer_nonselecting_chains) = map { +{
+ map { $_ => 1 } map { values %$_} map { @{$_->{-parents}} } values %{ $outer_aliastypes->{$_} || {} }
+ } } qw/selecting restricting grouping ordering/;
# see what's left - throw away if not selecting/restricting
- # also throw in a group_by if a non-selecting multiplier,
- # to guard against cross-join explosions
- my $need_outer_group_by;
- while (my $j = shift @$from) {
+ my $may_need_outer_group_by;
+ while (my $j = shift @orig_from) {
my $alias = $j->[0]{-alias};
if (
) {
push @outer_from, $j
}
- elsif ($outer_restrict_chain->{$alias}) {
+ elsif (first { $_->{$alias} } @outer_nonselecting_chains ) {
push @outer_from, $j;
- $need_outer_group_by ||= $outer_aliastypes->{multiplying}{$alias} ? 1 : 0;
+ $may_need_outer_group_by ||= $outer_aliastypes->{multiplying}{$alias} ? 1 : 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;
-
+ # also throw in a synthetic group_by if a non-selecting multiplier,
+ # to guard against cross-join explosions
+ # the logic is somewhat fragile, but relies on the idea that if a user supplied
+ # a group by on their own - they know what they were doing
+ if ( $may_need_outer_group_by and $attrs->{_grouped_by_distinct} ) {
+ ($outer_attrs->{group_by}, $outer_attrs->{order_by}) = $self->_group_over_selection ({
+ %$outer_attrs,
+ from => \@outer_from,
+ });
}
- # This is totally horrific - the $where ends up in both the inner and outer query
+ # 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
# to both filter the inner select (e.g. to apply a limit) and then have to re-filter
- # the outer select to exclude joins you didin't want in the first place
+ # the outer select to exclude joins you didn't want in the first place
#
# OTOH it can be seen as a plus: <ash> (notes that this query would make a DBA cry ;)
- return (\@outer_from, $outer_select, $where, $outer_attrs);
+ return $outer_attrs;
}
#
#
# Due to a lack of SQLA2 we fall back to crude scans of all the
# select/where/order/group attributes, in order to determine what
-# aliases are neded to fulfill the query. This information is used
+# aliases are needed to fulfill the query. This information is used
# throughout the code to prune unnecessary JOINs from the queries
# in an attempt to reduce the execution time.
# Although the method is pretty horrific, the worst thing that can
# happen is for it to fail due to some scalar SQL, which in turn will
# result in a vocal exception.
sub _resolve_aliastypes_from_select_args {
- my ( $self, $from, $select, $where, $attrs ) = @_;
+ my ( $self, $attrs ) = @_;
$self->throw_exception ('Unable to analyze custom {from}')
- if ref $from ne 'ARRAY';
+ if ref $attrs->{from} ne 'ARRAY';
# what we will return
my $aliases_by_type;
# see what aliases are there to work with
+ # and record who is a multiplier and who is premultiplied
my $alias_list;
- for (@$from) {
- my $j = $_;
+ for my $node (@{$attrs->{from}}) {
+
+ my $j = $node;
$j = $j->[0] if ref $j eq 'ARRAY';
my $al = $j->{-alias}
or next;
$alias_list->{$al} = $j;
- $aliases_by_type->{multiplying}{$al} ||= { -parents => $j->{-join_path}||[] } if (
+
+ $aliases_by_type->{multiplying}{$al} ||= { -parents => $j->{-join_path}||[] }
# not array == {from} head == can't be multiplying
- ( ref($_) eq 'ARRAY' and ! $j->{-is_single} )
- or
- # a parent of ours is already a multiplier
- ( grep { $aliases_by_type->{multiplying}{$_} } @{ $j->{-join_path}||[] } )
- );
+ if ref($node) eq 'ARRAY' and ! $j->{-is_single};
+
+ $aliases_by_type->{premultiplied}{$al} ||= { -parents => $j->{-join_path}||[] }
+ # parts of the path that are not us but are multiplying
+ if grep { $aliases_by_type->{multiplying}{$_} }
+ grep { $_ ne $al }
+ map { values %$_ }
+ @{ $j->{-join_path}||[] }
}
- # get a column to source/alias map (including unqualified ones)
- my $colinfo = $self->_resolve_column_info ($from);
+ # get a column to source/alias map (including unambiguous unqualified ones)
+ my $colinfo = $self->_resolve_column_info ($attrs->{from});
# set up a botched SQLA
my $sql_maker = $self->sql_maker;
# 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};
# generate sql chunks
my $to_scan = {
restricting => [
- $sql_maker->_recurse_where ($where),
- $sql_maker->_parse_rs_attrs ({
- map { $_ => $attrs->{$_} } (qw/group_by having/)
- }),
+ ($sql_maker->_recurse_where ($attrs->{where}))[0],
+ $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} }),
+ ],
+ grouping => [
+ $sql_maker->_parse_rs_attrs ({ group_by => $attrs->{group_by} }),
],
joining => [
$sql_maker->_recurse_from (
- ref $from->[0] eq 'ARRAY' ? $from->[0][0] : $from->[0],
- @{$from}[1 .. $#$from],
+ ref $attrs->{from}[0] eq 'ARRAY' ? $attrs->{from}[0][0] : $attrs->{from}[0],
+ @{$attrs->{from}}[1 .. $#{$attrs->{from}}],
),
],
selecting => [
- $sql_maker->_recurse_fields ($select),
- ( map { $_->[0] } $self->_extract_order_criteria ($attrs->{order_by}, $sql_maker) ),
+ # kill all selectors which look like a proper subquery
+ # this is a sucky heuristic *BUT* - if we get it wrong the query will simply
+ # fail to run, so we are relatively safe
+ grep
+ { $_ !~ / \A \s* \( \s* SELECT \s+ .+? \s+ FROM \s+ .+? \) \s* \z /xsi }
+ map
+ { ($sql_maker->_recurse_fields($_))[0] }
+ @{$attrs->{select}}
+ ],
+ ordering => [
+ map { $_->[0] } $self->_extract_order_criteria ($attrs->{order_by}, $sql_maker),
],
};
- # throw away empty chunks
- $_ = [ map { $_ || () } @$_ ] for values %$to_scan;
+ # throw away empty-string chunks, and make sure no binds snuck in
+ # note that we operate over @{$to_scan->{$type}}, hence the
+ # semi-mindbending ... map ... for values ...
+ ( $_ = [ map {
+
+ (not $_) ? ()
+ : (length ref $_) ? (require Data::Dumper::Concise && $self->throw_exception(
+ "Unexpected ref in scan-plan: " . Data::Dumper::Concise::Dumper($_)
+ ))
+ : $_
+
+ } @$_ ] ) for values %$to_scan;
+
+ # throw away empty to-scan's
+ (
+ @{$to_scan->{$_}}
+ or
+ delete $to_scan->{$_}
+ ) for keys %$to_scan;
+
+
+ # first see if we have any exact matches (qualified or unqualified)
+ for my $type (keys %$to_scan) {
+ for my $piece (@{$to_scan->{$type}}) {
+ if ($colinfo->{$piece} and my $alias = $colinfo->{$piece}{-source_alias}) {
+ $aliases_by_type->{$type}{$alias} ||= { -parents => $alias_list->{$alias}{-join_path}||[] };
+ $aliases_by_type->{$type}{$alias}{-seen_columns}{$colinfo->{$piece}{-fq_colname}} = $piece;
+ }
+ }
+ }
- # first loop through all fully qualified columns and get the corresponding
+ # now loop through all fully qualified columns and get the corresponding
# alias (should work even if they are in scalarrefs)
for my $alias (keys %$alias_list) {
my $al_re = qr/
for my $piece (@{$to_scan->{$type}}) {
if (my @matches = $piece =~ /$al_re/g) {
$aliases_by_type->{$type}{$alias} ||= { -parents => $alias_list->{$alias}{-join_path}||[] };
- $aliases_by_type->{$type}{$alias}{-seen_columns}{"$alias.$_"} = 1
+ $aliases_by_type->{$type}{$alias}{-seen_columns}{"$alias.$_"} = "$alias.$_"
for grep { defined $_ } @matches;
}
}
for my $type (keys %$to_scan) {
for my $piece (@{$to_scan->{$type}}) {
- if (my @matches = $piece =~ /$col_re/g) {
+ if ( my @matches = $piece =~ /$col_re/g) {
my $alias = $colinfo->{$col}{-source_alias};
$aliases_by_type->{$type}{$alias} ||= { -parents => $alias_list->{$alias}{-join_path}||[] };
- $aliases_by_type->{$type}{$alias}{-seen_columns}{"$alias.$_"} = 1
+ $aliases_by_type->{$type}{$alias}{-seen_columns}{"$alias.$_"} = $_
for grep { defined $_ } @matches;
}
}
);
}
+ for (keys %$aliases_by_type) {
+ delete $aliases_by_type->{$_} unless keys %{$aliases_by_type->{$_}};
+ }
+
return $aliases_by_type;
}
-# This is the engine behind { distinct => 1 }
+# This is the engine behind { distinct => 1 } and the general
+# complex prefetch grouper
sub _group_over_selection {
- my ($self, $from, $select, $order_by) = @_;
+ my ($self, $attrs) = @_;
- my $rs_column_list = $self->_resolve_column_info ($from);
+ my $colinfos = $self->_resolve_column_info ($attrs->{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 (@$select) {
+ for (@{$attrs->{select}}) {
if (! ref($_) or ref ($_) ne 'HASH' ) {
push @group_by, $_;
$group_index{$_}++;
- if ($rs_column_list->{$_} and $_ !~ /\./ ) {
+ if ($colinfos->{$_} and $_ !~ /\./ ) {
# add a fully qualified version as well
- $group_index{"$rs_column_list->{$_}{-source_alias}.$_"}++;
+ $group_index{"$colinfos->{$_}{-source_alias}.$_"}++;
}
}
}
+ my @order_by = $self->_extract_order_criteria($attrs->{order_by})
+ or return (\@group_by, $attrs->{order_by});
+
# add any order_by parts that are not already present in the group_by
- # we need to be careful not to add any named functions/aggregates
- # i.e. order_by => [ ... { count => 'foo' } ... ]
- my @leftovers;
- for ($self->_extract_order_criteria($order_by)) {
+ # to maintain SQL cross-compatibility and general sanity
+ #
+ # also in case the original selection is *not* unique, or in case part
+ # of the ORDER BY refers to a multiplier - we will need to replace the
+ # skipped order_by elements with their MIN/MAX equivalents as to maintain
+ # the proper overall order without polluting the group criteria (and
+ # possibly changing the outcome entirely)
+
+ my ($leftovers, $sql_maker, @new_order_by, $order_chunks, $aliastypes);
+
+ my $group_already_unique = $self->_columns_comprise_identifying_set($colinfos, \@group_by);
+
+ for my $o_idx (0 .. $#order_by) {
+
+ # if the chunk is already a min/max function - there is nothing left to touch
+ next if $order_by[$o_idx][0] =~ /^ (?: min | max ) \s* \( .+ \) $/ix;
+
# only consider real columns (for functions the user got to do an explicit group_by)
- if (@$_ != 1) {
- push @leftovers, $_;
- next;
- }
- my $chunk = $_->[0];
- my $colinfo = $rs_column_list->{$chunk} or do {
- push @leftovers, $_;
- next;
- };
+ my $chunk_ci;
+ if (
+ @{$order_by[$o_idx]} != 1
+ or
+ # only declare an unknown *plain* identifier as "leftover" if we are called with
+ # aliastypes to examine. If there are none - we are still in _resolve_attrs, and
+ # can just assume the user knows what they want
+ ( ! ( $chunk_ci = $colinfos->{$order_by[$o_idx][0]} ) and $attrs->{_aliastypes} )
+ ) {
+ push @$leftovers, $order_by[$o_idx][0];
+ }
+
+ next unless $chunk_ci;
+
+ # no duplication of group criteria
+ next if $group_index{$chunk_ci->{-fq_colname}};
+
+ $aliastypes ||= (
+ $attrs->{_aliastypes}
+ or
+ $self->_resolve_aliastypes_from_select_args({
+ from => $attrs->{from},
+ order_by => $attrs->{order_by},
+ })
+ ) if $group_already_unique;
+
+ # check that we are not ordering by a multiplier (if a check is requested at all)
+ if (
+ $group_already_unique
+ and
+ ! $aliastypes->{multiplying}{$chunk_ci->{-source_alias}}
+ and
+ ! $aliastypes->{premultiplied}{$chunk_ci->{-source_alias}}
+ ) {
+ push @group_by, $chunk_ci->{-fq_colname};
+ $group_index{$chunk_ci->{-fq_colname}}++
+ }
+ else {
+ # We need to order by external columns without adding them to the group
+ # (eiehter a non-unique selection, or a multi-external)
+ #
+ # This doesn't really make sense in SQL, however from DBICs point
+ # of view is rather valid (e.g. order the leftmost objects by whatever
+ # criteria and get the offset/rows many). There is a way around
+ # this however in SQL - we simply tae the direction of each piece
+ # of the external order and convert them to MIN(X) for ASC or MAX(X)
+ # for DESC, and group_by the root columns. The end result should be
+ # exactly what we expect
+
+ # FIXME - this code is a joke, will need to be completely rewritten in
+ # the DQ branch. But I need to push a POC here, otherwise the
+ # pesky tests won't pass
+ # wrap any part of the order_by that "responds" to an ordering alias
+ # into a MIN/MAX
+ $sql_maker ||= $self->sql_maker;
+ $order_chunks ||= [
+ map { ref $_ eq 'ARRAY' ? $_ : [ $_ ] } $sql_maker->_order_by_chunks($attrs->{order_by})
+ ];
- $chunk = "$colinfo->{-source_alias}.$chunk" if $chunk !~ /\./;
- push @group_by, $chunk unless $group_index{$chunk}++;
+ my ($chunk, $is_desc) = $sql_maker->_split_order_chunk($order_chunks->[$o_idx][0]);
+
+ $new_order_by[$o_idx] = \[
+ sprintf( '%s( %s )%s',
+ ($is_desc ? 'MAX' : 'MIN'),
+ $chunk,
+ ($is_desc ? ' DESC' : ''),
+ ),
+ @ {$order_chunks->[$o_idx]} [ 1 .. $#{$order_chunks->[$o_idx]} ]
+ ];
+ }
}
- return wantarray
- ? (\@group_by, (@leftovers ? \@leftovers : undef) )
- : \@group_by
- ;
+ $self->throw_exception ( sprintf
+ 'Unable to programatically derive a required group_by from the supplied '
+ . 'order_by criteria. To proceed either add an explicit group_by, or '
+ . 'simplify your order_by to only include plain columns '
+ . '(supplied order_by: %s)',
+ join ', ', map { "'$_'" } @$leftovers,
+ ) if $leftovers;
+
+ # recreate the untouched order parts
+ if (@new_order_by) {
+ $new_order_by[$_] ||= \ $order_chunks->[$_] for ( 0 .. $#$order_chunks );
+ }
+
+ return (
+ \@group_by,
+ (@new_order_by ? \@new_order_by : $attrs->{order_by} ), # same ref as original == unchanged
+ );
}
sub _resolve_ident_sources {
my ($self, $ident) = @_;
my $alias2source = {};
- my $rs_alias;
# the reason this is so contrived is that $ident may be a {from}
# structure, specifying multiple tables to join
if ( blessed $ident && $ident->isa("DBIx::Class::ResultSource") ) {
# this is compat mode for insert/update/delete which do not deal with aliases
$alias2source->{me} = $ident;
- $rs_alias = 'me';
}
elsif (ref $ident eq 'ARRAY') {
my $tabinfo;
if (ref $_ eq 'HASH') {
$tabinfo = $_;
- $rs_alias = $tabinfo->{-alias};
}
if (ref $_ eq 'ARRAY' and ref $_->[0] eq 'HASH') {
$tabinfo = $_->[0];
}
}
- return ($alias2source, $rs_alias);
+ return $alias2source;
}
# Takes $ident, \@column_names
# for all sources
sub _resolve_column_info {
my ($self, $ident, $colnames) = @_;
- my ($alias2src, $root_alias) = $self->_resolve_ident_sources($ident);
+
+ return {} if $colnames and ! @$colnames;
+
+ my $alias2src = $self->_resolve_ident_sources($ident);
my (%seen_cols, @auto_colnames);
sub _inner_join_to_node {
my ($self, $from, $alias) = @_;
- # subqueries and other oddness are naturally not supported
- return $from if (
- ref $from ne 'ARRAY'
- ||
- @$from <= 1
- ||
- ref $from->[0] ne 'HASH'
- ||
- ! $from->[0]{-alias}
- ||
- $from->[0]{-alias} eq $alias # this last bit means $alias is the head of $from - nothing to do
- );
-
- # find the current $alias in the $from structure
- my $switch_branch;
- JOINSCAN:
- for my $j (@{$from}[1 .. $#$from]) {
- if ($j->[0]{-alias} eq $alias) {
- $switch_branch = $j->[0]{-join_path};
- last JOINSCAN;
- }
- }
+ my $switch_branch = $self->_find_join_path_to_node($from, $alias);
- # something else went quite wrong
- return $from unless $switch_branch;
+ return $from unless @{$switch_branch||[]};
# So it looks like we will have to switch some stuff around.
# local() is useless here as we will be leaving the scope
return \@new_from;
}
+sub _find_join_path_to_node {
+ my ($self, $from, $target_alias) = @_;
+
+ # subqueries and other oddness are naturally not supported
+ return undef if (
+ ref $from ne 'ARRAY'
+ ||
+ ref $from->[0] ne 'HASH'
+ ||
+ ! defined $from->[0]{-alias}
+ );
+
+ # no path - the head is the alias
+ return [] if $from->[0]{-alias} eq $target_alias;
+
+ for my $i (1 .. $#$from) {
+ return $from->[$i][0]{-join_path} if ( ($from->[$i][0]{-alias}||'') eq $target_alias );
+ }
+
+ # something else went quite wrong
+ return undef;
+}
+
sub _extract_order_criteria {
my ($self, $order_by, $sql_maker) = @_;
my $parser = sub {
- my ($sql_maker, $order_by) = @_;
+ my ($sql_maker, $order_by, $orig_quote_chars) = @_;
return scalar $sql_maker->_order_by_chunks ($order_by)
unless wantarray;
+ my ($lq, $rq, $sep) = map { quotemeta($_) } (
+ ($orig_quote_chars ? @$orig_quote_chars : $sql_maker->_quote_chars),
+ $sql_maker->name_sep
+ );
+
my @chunks;
for ($sql_maker->_order_by_chunks ($order_by) ) {
- my $chunk = ref $_ ? $_ : [ $_ ];
- $chunk->[0] =~ s/\s+ (?: ASC|DESC ) \s* $//ix;
+ my $chunk = ref $_ ? [ @$_ ] : [ $_ ];
+ ($chunk->[0]) = $sql_maker->_split_order_chunk($chunk->[0]);
+
+ # order criteria may have come back pre-quoted (literals and whatnot)
+ # this is fragile, but the best we can currently do
+ $chunk->[0] =~ s/^ $lq (.+?) $rq $sep $lq (.+?) $rq $/"$1.$2"/xe
+ or $chunk->[0] =~ s/^ $lq (.+) $rq $/$1/x;
+
push @chunks, $chunk;
}
}
else {
$sql_maker = $self->sql_maker;
+
+ # pass these in to deal with literals coming from
+ # the user or the deep guts of prefetch
+ my $orig_quote_chars = [$sql_maker->_quote_chars];
+
local $sql_maker->{quote_char};
- return $parser->($sql_maker, $order_by);
+ return $parser->($sql_maker, $order_by, $orig_quote_chars);
}
}
sub _order_by_is_stable {
my ($self, $ident, $order_by, $where) = @_;
- my $colinfo = $self->_resolve_column_info($ident, [
- (map { $_->[0] } $self->_extract_order_criteria($order_by)),
- $where ? @{$self->_extract_fixed_condition_columns($where)} :(),
- ]);
+ my @cols = (
+ ( map { $_->[0] } $self->_extract_order_criteria($order_by) ),
+ ( $where ? keys %{ $self->_extract_fixed_condition_columns($where) } : () ),
+ ) or return 0;
+
+ my $colinfo = $self->_resolve_column_info($ident, \@cols);
+
+ return keys %$colinfo
+ ? $self->_columns_comprise_identifying_set( $colinfo, \@cols )
+ : 0
+ ;
+}
- return undef unless keys %$colinfo;
+sub _columns_comprise_identifying_set {
+ my ($self, $colinfo, $columns) = @_;
my $cols_per_src;
- $cols_per_src->{$_->{-source_alias}}{$_->{-colname}} = $_ for values %$colinfo;
+ $cols_per_src -> {$_->{-source_alias}} -> {$_->{-colname}} = $_
+ for grep { defined $_ } @{$colinfo}{@$columns};
for (values %$cols_per_src) {
my $src = (values %$_)[0]->{-result_source};
return 1 if $src->_identifying_column_set($_);
}
- return undef;
+ return 0;
}
-# returns an arrayref of column names which *definitely* have som
-# sort of non-nullable equality requested in the given condition
-# specification. This is used to figure out if a resultset is
-# constrained to a column which is part of a unique constraint,
-# which in turn allows us to better predict how ordering will behave
-# etc.
+# this is almost similar to _order_by_is_stable, except it takes
+# a single rsrc, and will succeed only if the first portion of the order
+# by is stable.
+# returns that portion as a colinfo hashref on success
+sub _extract_colinfo_of_stable_main_source_order_by_portion {
+ my ($self, $attrs) = @_;
+
+ my $nodes = $self->_find_join_path_to_node($attrs->{from}, $attrs->{alias});
+
+ return unless defined $nodes;
+
+ my @ord_cols = map
+ { $_->[0] }
+ ( $self->_extract_order_criteria($attrs->{order_by}) )
+ ;
+ return unless @ord_cols;
+
+ my $valid_aliases = { map { $_ => 1 } (
+ $attrs->{from}[0]{-alias},
+ map { values %$_ } @$nodes,
+ ) };
+
+ my $colinfos = $self->_resolve_column_info($attrs->{from});
+
+ my ($colinfos_to_return, $seen_main_src_cols);
+
+ for my $col (@ord_cols) {
+ # if order criteria is unresolvable - there is nothing we can do
+ my $colinfo = $colinfos->{$col} or last;
+
+ # if we reached the end of the allowed aliases - also nothing we can do
+ last unless $valid_aliases->{$colinfo->{-source_alias}};
+
+ $colinfos_to_return->{$col} = $colinfo;
+
+ $seen_main_src_cols->{$colinfo->{-colname}} = 1
+ if $colinfo->{-source_alias} eq $attrs->{alias};
+ }
+
+ # FIXME the condition may be singling out things on its own, so we
+ # conceivable could come back wi "stable-ordered by nothing"
+ # not confient enough in the parser yet, so punt for the time being
+ return unless $seen_main_src_cols;
+
+ my $main_src_fixed_cols_from_cond = [ $attrs->{where}
+ ? (
+ map
+ {
+ ( $colinfos->{$_} and $colinfos->{$_}{-source_alias} eq $attrs->{alias} )
+ ? $colinfos->{$_}{-colname}
+ : ()
+ }
+ keys %{ $self->_extract_fixed_condition_columns($attrs->{where}) }
+ )
+ : ()
+ ];
+
+ return $attrs->{result_source}->_identifying_column_set([
+ keys %$seen_main_src_cols,
+ @$main_src_fixed_cols_from_cond,
+ ]) ? $colinfos_to_return : ();
+}
+
+# Attempts to flatten a passed in SQLA condition as much as possible towards
+# a plain hashref, *without* altering its semantics. Required by
+# create/populate being able to extract definitive conditions from preexisting
+# resultset {where} stacks
+#
+# FIXME - while relatively robust, this is still imperfect, one of the first
+# things to tackle with DQ
+sub _collapse_cond {
+ my ($self, $where, $where_is_anded_array) = @_;
+
+ my $fin;
+
+ if (! $where) {
+ return;
+ }
+ elsif ($where_is_anded_array or ref $where eq 'HASH') {
+
+ my @pairs;
+
+ my @pieces = $where_is_anded_array ? @$where : $where;
+ while (@pieces) {
+ my $chunk = shift @pieces;
+
+ if (ref $chunk eq 'HASH') {
+ for (sort keys %$chunk) {
+
+ # Match SQLA 1.79 behavior
+ if ($_ eq '') {
+ is_literal_value($chunk->{$_})
+ ? carp 'Hash-pairs consisting of an empty string with a literal are deprecated, use -and => [ $literal ] instead'
+ : $self->throw_exception("Supplying an empty left hand side argument is not supported in hash-pairs")
+ ;
+ }
+
+ push @pairs, $_ => $chunk->{$_};
+ }
+ }
+ elsif (ref $chunk eq 'ARRAY') {
+ push @pairs, -or => $chunk
+ if @$chunk;
+ }
+ elsif ( ! length ref $chunk) {
+
+ # Match SQLA 1.79 behavior
+ $self->throw_exception("Supplying an empty left hand side argument is not supported in array-pairs")
+ if $where_is_anded_array and (! defined $chunk or $chunk eq '');
+
+ push @pairs, $chunk, shift @pieces;
+ }
+ else {
+ push @pairs, '', $chunk;
+ }
+ }
+
+ return unless @pairs;
+
+ my @conds = $self->_collapse_cond_unroll_pairs(\@pairs)
+ or return;
+
+ # Consolidate various @conds back into something more compact
+ for my $c (@conds) {
+ if (ref $c ne 'HASH') {
+ push @{$fin->{-and}}, $c;
+ }
+ else {
+ for my $col (sort keys %$c) {
+
+ # consolidate all -and nodes
+ if ($col =~ /^\-and$/i) {
+ push @{$fin->{-and}},
+ ref $c->{$col} eq 'ARRAY' ? @{$c->{$col}}
+ : ref $c->{$col} eq 'HASH' ? %{$c->{$col}}
+ : { $col => $c->{$col} }
+ ;
+ }
+ elsif ($col =~ /^\-/) {
+ push @{$fin->{-and}}, { $col => $c->{$col} };
+ }
+ elsif (exists $fin->{$col}) {
+ $fin->{$col} = [ -and => map {
+ (ref $_ eq 'ARRAY' and ($_->[0]||'') =~ /^\-and$/i )
+ ? @{$_}[1..$#$_]
+ : $_
+ ;
+ } ($fin->{$col}, $c->{$col}) ];
+ }
+ else {
+ $fin->{$col} = $c->{$col};
+ }
+ }
+ }
+ }
+ }
+ elsif (ref $where eq 'ARRAY') {
+ # we are always at top-level here, it is safe to dump empty *standalone* pieces
+ my $fin_idx;
+
+ for (my $i = 0; $i <= $#$where; $i++ ) {
+
+ # Match SQLA 1.79 behavior
+ $self->throw_exception(
+ "Supplying an empty left hand side argument is not supported in array-pairs"
+ ) if (! defined $where->[$i] or ! length $where->[$i]);
+
+ my $logic_mod = lc ( ($where->[$i] =~ /^(\-(?:and|or))$/i)[0] || '' );
+
+ if ($logic_mod) {
+ $i++;
+ $self->throw_exception("Unsupported top-level op/arg pair: [ $logic_mod => $where->[$i] ]")
+ unless ref $where->[$i] eq 'HASH' or ref $where->[$i] eq 'ARRAY';
+
+ my $sub_elt = $self->_collapse_cond({ $logic_mod => $where->[$i] })
+ or next;
+
+ my @keys = keys %$sub_elt;
+ if ( @keys == 1 and $keys[0] !~ /^\-/ ) {
+ $fin_idx->{ "COL_$keys[0]_" . serialize $sub_elt } = $sub_elt;
+ }
+ else {
+ $fin_idx->{ "SER_" . serialize $sub_elt } = $sub_elt;
+ }
+ }
+ elsif (! length ref $where->[$i] ) {
+ my $sub_elt = $self->_collapse_cond({ @{$where}[$i, $i+1] })
+ or next;
+
+ $fin_idx->{ "COL_$where->[$i]_" . serialize $sub_elt } = $sub_elt;
+ $i++;
+ }
+ else {
+ $fin_idx->{ "SER_" . serialize $where->[$i] } = $self->_collapse_cond( $where->[$i] ) || next;
+ }
+ }
+
+ if (! $fin_idx) {
+ return;
+ }
+ elsif ( keys %$fin_idx == 1 ) {
+ $fin = (values %$fin_idx)[0];
+ }
+ else {
+ my @or;
+
+ # at this point everything is at most one level deep - unroll if needed
+ for (sort keys %$fin_idx) {
+ if ( ref $fin_idx->{$_} eq 'HASH' and keys %{$fin_idx->{$_}} == 1 ) {
+ my ($l, $r) = %{$fin_idx->{$_}};
+
+ if (
+ ref $r eq 'ARRAY'
+ and
+ (
+ ( @$r == 1 and $l =~ /^\-and$/i )
+ or
+ $l =~ /^\-or$/i
+ )
+ ) {
+ push @or, @$r
+ }
+
+ elsif (
+ ref $r eq 'HASH'
+ and
+ keys %$r == 1
+ and
+ $l =~ /^\-(?:and|or)$/i
+ ) {
+ push @or, %$r;
+ }
+
+ else {
+ push @or, $l, $r;
+ }
+ }
+ else {
+ push @or, $fin_idx->{$_};
+ }
+ }
+
+ $fin->{-or} = \@or;
+ }
+ }
+ else {
+ # not a hash not an array
+ $fin = { -and => [ $where ] };
+ }
+
+ # unroll single-element -and's
+ while (
+ $fin->{-and}
+ and
+ @{$fin->{-and}} < 2
+ ) {
+ my $and = delete $fin->{-and};
+ last if @$and == 0;
+
+ # at this point we have @$and == 1
+ if (
+ ref $and->[0] eq 'HASH'
+ and
+ ! grep { exists $fin->{$_} } keys %{$and->[0]}
+ ) {
+ $fin = {
+ %$fin, %{$and->[0]}
+ };
+ }
+ else {
+ $fin->{-and} = $and;
+ last;
+ }
+ }
+
+ # compress same-column conds found in $fin
+ for my $col ( grep { $_ !~ /^\-/ } keys %$fin ) {
+ next unless ref $fin->{$col} eq 'ARRAY' and ($fin->{$col}[0]||'') =~ /^\-and$/i;
+ my $val_bag = { map {
+ (! defined $_ ) ? ( UNDEF => undef )
+ : ( ! length ref $_ or is_plain_value $_ ) ? ( "VAL_$_" => $_ )
+ : ( ( 'SER_' . serialize $_ ) => $_ )
+ } @{$fin->{$col}}[1 .. $#{$fin->{$col}}] };
+
+ if (keys %$val_bag == 1 ) {
+ ($fin->{$col}) = values %$val_bag;
+ }
+ else {
+ $fin->{$col} = [ -and => map { $val_bag->{$_} } sort keys %$val_bag ];
+ }
+ }
+
+ return keys %$fin ? $fin : ();
+}
+
+sub _collapse_cond_unroll_pairs {
+ my ($self, $pairs) = @_;
+
+ my @conds;
+
+ while (@$pairs) {
+ my ($lhs, $rhs) = splice @$pairs, 0, 2;
+
+ if ($lhs eq '') {
+ push @conds, $self->_collapse_cond($rhs);
+ }
+ elsif ( $lhs =~ /^\-and$/i ) {
+ push @conds, $self->_collapse_cond($rhs, (ref $rhs eq 'ARRAY'));
+ }
+ elsif ( $lhs =~ /^\-or$/i ) {
+ push @conds, $self->_collapse_cond(
+ (ref $rhs eq 'HASH') ? [ map { $_ => $rhs->{$_} } sort keys %$rhs ] : $rhs
+ );
+ }
+ else {
+ if (ref $rhs eq 'HASH' and ! keys %$rhs) {
+ # FIXME - SQLA seems to be doing... nothing...?
+ }
+ # normalize top level -ident, for saner extract_fixed_condition_columns code
+ elsif (ref $rhs eq 'HASH' and keys %$rhs == 1 and exists $rhs->{-ident}) {
+ push @conds, { $lhs => { '=', $rhs } };
+ }
+ elsif (ref $rhs eq 'HASH' and keys %$rhs == 1 and exists $rhs->{-value} and is_plain_value $rhs->{-value}) {
+ push @conds, { $lhs => $rhs->{-value} };
+ }
+ elsif (ref $rhs eq 'HASH' and keys %$rhs == 1 and exists $rhs->{'='}) {
+ if ( length ref $rhs->{'='} and is_literal_value $rhs->{'='} ) {
+ push @conds, { $lhs => $rhs };
+ }
+ else {
+ for my $p ($self->_collapse_cond_unroll_pairs([ $lhs => $rhs->{'='} ])) {
+
+ # extra sanity check
+ if (keys %$p > 1) {
+ require Data::Dumper::Concise;
+ local $Data::Dumper::Deepcopy = 1;
+ $self->throw_exception(
+ "Internal error: unexpected collapse unroll:"
+ . Data::Dumper::Concise::Dumper { in => { $lhs => $rhs }, out => $p }
+ );
+ }
+
+ my ($l, $r) = %$p;
+
+ push @conds, (
+ ! length ref $r
+ or
+ # the unroller recursion may return a '=' prepended value already
+ ref $r eq 'HASH' and keys %$rhs == 1 and exists $rhs->{'='}
+ or
+ is_plain_value($r)
+ )
+ ? { $l => $r }
+ : { $l => { '=' => $r } }
+ ;
+ }
+ }
+ }
+ elsif (ref $rhs eq 'ARRAY') {
+ # some of these conditionals encounter multi-values - roll them out using
+ # an unshift, which will cause extra looping in the while{} above
+ if (! @$rhs ) {
+ push @conds, { $lhs => [] };
+ }
+ elsif ( ($rhs->[0]||'') =~ /^\-(?:and|or)$/i ) {
+ $self->throw_exception("Value modifier not followed by any values: $lhs => [ $rhs->[0] ] ")
+ if @$rhs == 1;
+
+ if( $rhs->[0] =~ /^\-and$/i ) {
+ unshift @$pairs, map { $lhs => $_ } @{$rhs}[1..$#$rhs];
+ }
+ # if not an AND then it's an OR
+ elsif(@$rhs == 2) {
+ unshift @$pairs, $lhs => $rhs->[1];
+ }
+ else {
+ push @conds, { $lhs => [ @{$rhs}[1..$#$rhs] ] };
+ }
+ }
+ elsif (@$rhs == 1) {
+ unshift @$pairs, $lhs => $rhs->[0];
+ }
+ else {
+ push @conds, { $lhs => $rhs };
+ }
+ }
+ # unroll func + { -value => ... }
+ elsif (
+ ref $rhs eq 'HASH'
+ and
+ ( my ($subop) = keys %$rhs ) == 1
+ and
+ length ref ((values %$rhs)[0])
+ and
+ my $vref = is_plain_value( (values %$rhs)[0] )
+ ) {
+ push @conds, { $lhs => { $subop => $$vref } }
+ }
+ else {
+ push @conds, { $lhs => $rhs };
+ }
+ }
+ }
+
+ return @conds;
+}
+
+# Analyzes a given condition and attempts to extract all columns
+# with a definitive fixed-condition criteria. Returns a hashref
+# of k/v pairs suitable to be passed to set_columns(), with a
+# MAJOR CAVEAT - multi-value (contradictory) equalities are still
+# represented as a reference to the UNRESOVABLE_CONDITION constant
+# The reason we do this is that some codepaths only care about the
+# codition being stable, as opposed to actually making sense
+#
+# The normal mode is used to figure out if a resultset is constrained
+# to a column which is part of a unique constraint, which in turn
+# allows us to better predict how ordering will behave etc.
+#
+# With the optional "consider_nulls" boolean argument, the function
+# is instead used to infer inambiguous values from conditions
+# (e.g. the inheritance of resultset conditions on new_result)
#
-# this is a rudimentary, incomplete, and error-prone extractor
-# however this is OK - it is conservative, and if we can not find
-# something that is in fact there - the stack will recover gracefully
-# Also - DQ and the mst it rode in on will save us all RSN!!!
sub _extract_fixed_condition_columns {
- my ($self, $where, $nested) = @_;
+ my ($self, $where, $consider_nulls) = @_;
+ my $where_hash = $self->_collapse_cond($_[1]);
- return unless ref $where eq 'HASH';
+ my $res = {};
+ my ($c, $v);
+ for $c (keys %$where_hash) {
+ my $vals;
- my @cols;
- for my $lhs (keys %$where) {
- if ($lhs =~ /^\-and$/i) {
- push @cols, ref $where->{$lhs} eq 'ARRAY'
- ? ( map { $self->_extract_fixed_condition_columns($_, 1) } @{$where->{$lhs}} )
- : $self->_extract_fixed_condition_columns($where->{$lhs}, 1)
- ;
+ if (!defined ($v = $where_hash->{$c}) ) {
+ $vals->{UNDEF} = $v if $consider_nulls
+ }
+ elsif (
+ ref $v eq 'HASH'
+ and
+ keys %$v == 1
+ ) {
+ if (exists $v->{-value}) {
+ if (defined $v->{-value}) {
+ $vals->{"VAL_$v->{-value}"} = $v->{-value}
+ }
+ elsif( $consider_nulls ) {
+ $vals->{UNDEF} = $v->{-value};
+ }
+ }
+ # do not need to check for plain values - _collapse_cond did it for us
+ elsif(
+ length ref $v->{'='}
+ and
+ (
+ ( ref $v->{'='} eq 'HASH' and keys %{$v->{'='}} == 1 and exists $v->{'='}{-ident} )
+ or
+ is_literal_value($v->{'='})
+ )
+ ) {
+ $vals->{ 'SER_' . serialize $v->{'='} } = $v->{'='};
+ }
+ }
+ elsif (
+ ! length ref $v
+ or
+ is_plain_value ($v)
+ ) {
+ $vals->{"VAL_$v"} = $v;
+ }
+ elsif (ref $v eq 'ARRAY' and ($v->[0]||'') eq '-and') {
+ for ( @{$v}[1..$#$v] ) {
+ my $subval = $self->_extract_fixed_condition_columns({ $c => $_ }, 'consider nulls'); # always fish nulls out on recursion
+ next unless exists $subval->{$c}; # didn't find anything
+ $vals->{
+ ! defined $subval->{$c} ? 'UNDEF'
+ : ( ! length ref $subval->{$c} or is_plain_value $subval->{$c} ) ? "VAL_$subval->{$c}"
+ : ( 'SER_' . serialize $subval->{$c} )
+ } = $subval->{$c};
+ }
}
- elsif ($lhs !~ /^\-/) {
- my $val = $where->{$lhs};
- push @cols, $lhs if (defined $val and (
- ! ref $val
- or
- (ref $val eq 'HASH' and keys %$val == 1 and defined $val->{'='})
- ));
+ if (keys %$vals == 1) {
+ ($res->{$c}) = (values %$vals)
+ unless !$consider_nulls and exists $vals->{UNDEF};
+ }
+ elsif (keys %$vals > 1) {
+ $res->{$c} = UNRESOLVABLE_CONDITION;
}
}
- return $nested ? @cols : \@cols;
+
+ $res;
}
1;
projects / dbsrgits/DBIx-Class.git / blobdiff