use mro 'c3';
use Carp::Clan qw/^DBIx::Class/;
+use List::Util 'first';
+use Scalar::Util 'blessed';
+use namespace::clean;
#
# This code will remove non-selecting/non-restricting joins from
-# {from} specs, aiding the RDBMS query optimizer.
+# {from} specs, aiding the RDBMS query optimizer
#
sub _prune_unused_joins {
my $self = shift;
+ my ($from, $select, $where, $attrs) = @_;
+
+ return $from unless $self->_use_join_optimizer;
- my $from = shift;
if (ref $from ne 'ARRAY' || ref $from->[0] ne 'HASH' || ref $from->[1] ne 'ARRAY') {
return $from; # only standard {from} specs are supported
}
- my $aliastypes = $self->_resolve_aliastypes_from_select_args($from, @_);
+ my $aliastypes = $self->_resolve_aliastypes_from_select_args(@_);
+
+ # a grouped set will not be affected by amount of rows. Thus any
+ # {multiplying} joins can go
+ delete $aliastypes->{multiplying} if $attrs->{group_by};
my @newfrom = $from->[0]; # FROM head is always present
my %need_joins = (map { %{$_||{}} } (values %$aliastypes) );
for my $j (@{$from}[1..$#$from]) {
push @newfrom, $j if (
- ! $j->[0]{-alias} # legacy crap
+ (! $j->[0]{-alias}) # legacy crap
||
$need_joins{$j->[0]{-alias}}
);
}
push @$inner_select, $sel;
+
+ push @{$inner_attrs->{as}}, $attrs->{as}[$i];
}
- # construct the inner $from for the subquery
- my $inner_from = $self->_prune_unused_joins ($from, $inner_select, $where, $inner_attrs);
+ # 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
+ # the fake group_by is so that the pruner throws away all non-selecting, non-restricting
+ # multijoins (since we def. do not care about those inside the subquery)
+
+ my $subq_joinspec = do {
+
+ # must use it here regardless of user requests
+ local $self->{_use_join_optimizer} = 1;
+
+ my $inner_from = $self->_prune_unused_joins ($from, $inner_select, $where, {
+ group_by => ['dummy'], %$inner_attrs,
+ });
+
+ 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;
+ }
- # 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 List::Util::first
- { ! $_->[0]{-is_single} }
- (@{$inner_from}[1 .. $#$inner_from])
- ;
+ # we already optimized $inner_from above
+ local $self->{_use_join_optimizer} = 0;
- # generate the subquery
- my $subq = $self->_select_args_to_query (
- $inner_from,
- $inner_select,
- $where,
- $inner_attrs,
- );
+ # generate the subquery
+ my $subq = $self->_select_args_to_query (
+ $inner_from,
+ $inner_select,
+ $where,
+ $inner_attrs,
+ );
- my $subq_joinspec = {
- -alias => $attrs->{alias},
- -source_handle => $inner_from->[0]{-source_handle},
- $attrs->{alias} => $subq,
+ +{
+ -alias => $attrs->{alias},
+ -source_handle => $inner_from->[0]{-source_handle},
+ $attrs->{alias} => $subq,
+ };
};
# Generate the outer from - this is relatively easy (really just replace
# - it is part of the restrictions, in which case we need to collapse the outer
# result by tackling yet another group_by to the outside of the query
- # normalize a copy of $from, so it will be easier to work with further
- # down (i.e. promote the initial hashref to an AoH)
$from = [ @$from ];
- $from->[0] = [ $from->[0] ];
# so first generate the outer_from, up to the substitution point
my @outer_from;
while (my $j = shift @$from) {
+ $j = [ $j ] unless ref $j eq 'ARRAY'; # promote the head-from to an AoH
+
if ($j->[0]{-alias} eq $attrs->{alias}) { # time to swap
push @outer_from, [
$subq_joinspec,
}
}
- # scan the from spec against different attributes, and see which joins are needed
+ # 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 );
while (my $j = shift @$from) {
my $alias = $j->[0]{-alias};
- if ($outer_aliastypes->{select}{$alias}) {
+ if ($outer_aliastypes->{selecting}{$alias}) {
push @outer_from, $j;
}
- elsif ($outer_aliastypes->{restrict}{$alias}) {
+ elsif ($outer_aliastypes->{restricting}{$alias}) {
push @outer_from, $j;
$outer_attrs->{group_by} ||= $outer_select unless $j->[0]{-is_single};
}
return (\@outer_from, $outer_select, $where, $outer_attrs);
}
+#
+# I KNOW THIS SUCKS! GET SQLA2 OUT THE DOOR SO THIS CAN DIE!
+#
# 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
# 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 an unqualified column, which in
-# turn will result in a vocal exception. Qualifying the column will
-# invariably solve the problem.
+# 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 ) = @_;
$alias_list->{$al} = $j;
$aliases_by_type->{multiplying}{$al} = 1
- unless $j->{-is_single};
+ if ref($_) eq 'ARRAY' and ! $j->{-is_single}; # not array == {from} head == can't be multiplying
}
+ # get a column to source/alias map (including unqualified ones)
+ my $colinfo = $self->_resolve_column_info ($from);
+
# set up a botched SQLA
my $sql_maker = $self->sql_maker;
- my $sep = quotemeta ($self->_sql_maker_opts->{name_sep} || '.');
- local $sql_maker->{quote_char}; # so that we can regex away
-
-
- my $select_sql = $sql_maker->_recurse_fields ($select);
- my $where_sql = $sql_maker->where ($where);
- my $group_by_sql = $sql_maker->_order_by({
- map { $_ => $attrs->{$_} } qw/group_by having/
- });
- my @order_by_chunks = (map
- { ref $_ ? $_->[0] : $_ }
- $sql_maker->_order_by_chunks ($attrs->{order_by})
- );
- # match every alias to the sql chunks above
- for my $alias (keys %$alias_list) {
- my $al_re = qr/\b $alias $sep/x;
+ # these are throw away results, do not pollute the bind stack
+ local $sql_maker->{having_bind};
+ local $sql_maker->{select_bind};
+
+ # we can't scan properly without any quoting (\b doesn't cut it
+ # everywhere), so unless there is proper quoting set - use our
+ # own weird impossible character.
+ # Also in the case of no quoting, we need to explicitly disable
+ # name_sep, otherwise sorry nasty legacy syntax like
+ # { 'count(foo.id)' => { '>' => 3 } } will stop working >:(
+ local $sql_maker->{quote_char} = $sql_maker->{quote_char};
+ 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", "\xFF"];
+ # if we don't unset it we screw up retarded but unfortunately working
+ # 'MAX(foo.bar)' => { '>', 3 }
+ $sql_maker->{name_sep} = '';
+ }
+
+ my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep);
+
+ # generate sql chunks
+ my $to_scan = {
+ restricting => [
+ $sql_maker->_recurse_where ($where),
+ $sql_maker->_parse_rs_attrs ({
+ map { $_ => $attrs->{$_} } (qw/group_by having/)
+ }),
+ ],
+ selecting => [
+ $sql_maker->_recurse_fields ($select),
+ ( map { $_->[0] } $self->_extract_order_criteria ($attrs->{order_by}, $sql_maker) ),
+ ],
+ };
- for my $piece ($where_sql, $group_by_sql) {
- $aliases_by_type->{restrict}{$alias} = 1 if ($piece =~ $al_re);
+ # throw away empty chunks
+ $_ = [ map { $_ || () } @$_ ] for values %$to_scan;
+
+ # first 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/
+ $lquote $alias $rquote $sep
+ |
+ \b $alias \.
+ /x;
+
+ for my $type (keys %$to_scan) {
+ for my $piece (@{$to_scan->{$type}}) {
+ $aliases_by_type->{$type}{$alias} = 1 if ($piece =~ $al_re);
+ }
}
+ }
- for my $piece ($select_sql, @order_by_chunks ) {
- $aliases_by_type->{select}{$alias} = 1 if ($piece =~ $al_re);
+ # now loop through unqualified column names, and try to locate them within
+ # the chunks
+ for my $col (keys %$colinfo) {
+ next if $col =~ / \. /x; # if column is qualified it was caught by the above
+
+ my $col_re = qr/ $lquote $col $rquote /x;
+
+ for my $type (keys %$to_scan) {
+ for my $piece (@{$to_scan->{$type}}) {
+ $aliases_by_type->{$type}{$colinfo->{$col}{-source_alias}} = 1 if ($piece =~ $col_re);
+ }
}
}
# Add any non-left joins to the restriction list (such joins are indeed restrictions)
for my $j (values %$alias_list) {
my $alias = $j->{-alias} or next;
- $aliases_by_type->{restrict}{$alias} = 1 if (
+ $aliases_by_type->{restricting}{$alias} = 1 if (
(not $j->{-join_type})
or
($j->{-join_type} !~ /^left (?: \s+ outer)? $/xi)
);
}
- # mark all join parents as mentioned
+ # mark all restricting/selecting join parents as such
# (e.g. join => { cds => 'tracks' } - tracks will need to bring cds too )
- for my $type (keys %$aliases_by_type) {
- for my $alias (keys %{$aliases_by_type->{$type}}) {
+ for my $type (qw/restricting selecting/) {
+ for my $alias (keys %{$aliases_by_type->{$type}||{}}) {
$aliases_by_type->{$type}{$_} = 1
- for (map { keys %$_ } @{ $alias_list->{$alias}{-join_path} || [] });
+ for (map { values %$_ } @{ $alias_list->{$alias}{-join_path} || [] });
}
}
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);
+
+ 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) = @_;
# the reason this is so contrived is that $ident may be a {from}
# structure, specifying multiple tables to join
- if ( Scalar::Util::blessed($ident) && $ident->isa("DBIx::Class::ResultSource") ) {
+ 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;
$rs_alias = 'me';
my ($self, $ident, $colnames) = @_;
my ($alias2src, $root_alias) = $self->_resolve_ident_sources($ident);
- my $sep = $self->_sql_maker_opts->{name_sep} || '.';
- my $qsep = quotemeta $sep;
-
- 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)
my $rsrc = $alias2src->{$alias};
for my $colname ($rsrc->columns) {
push @{$seen_cols{$colname}}, $alias;
- push @auto_colnames, "$alias$sep$colname" unless $colnames;
+ push @auto_colnames, "$alias.$colname" unless $colnames;
}
}
grep { @{$seen_cols{$_}} == 1 } (keys %seen_cols),
];
- COLUMN:
+ my (%return, $colinfos);
foreach my $col (@$colnames) {
- my ($alias, $colname) = $col =~ m/^ (?: ([^$qsep]+) $qsep)? (.+) $/x;
+ my ($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 => $source_alias,
};
}
# the top of the stack, and if not - make sure the chain is inner-joined down
# to the root.
#
-sub _straight_join_to_node {
+sub _inner_join_to_node {
my ($self, $from, $alias) = @_;
# subqueries and other oddness are naturally not supported
# anyway, and deep cloning is just too fucking expensive
# So replace the first hashref in the node arrayref manually
my @new_from = ($from->[0]);
- my $sw_idx = { map { values %$_ => 1 } @$switch_branch };
+ my $sw_idx = { map { (values %$_), 1 } @$switch_branch }; #there's one k/v per join-path
for my $j (@{$from}[1 .. $#$from]) {
my $jalias = $j->[0]{-alias};
for (my $i = 0; $i < @cond; $i++) {
my $entry = $cond[$i];
my $hash;
- if (ref $entry eq 'HASH') {
+ my $ref = ref $entry;
+ if ($ref eq 'HASH' or $ref eq 'ARRAY') {
$hash = $self->_strip_cond_qualifiers($entry);
}
- else {
+ 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;
}
}
else {
foreach my $key (keys %$where) {
- $key =~ /([^.]+)$/;
- $cond->{$1} = $where->{$key};
+ if ($key eq '-or' && ref $where->{$key} eq 'ARRAY') {
+ $cond->{$key} = $self->_strip_cond_qualifiers($where->{$key});
+ }
+ else {
+ $key =~ /([^.]+)$/;
+ $cond->{$1} = $where->{$key};
+ }
}
}
}
return $cond;
}
+sub _extract_order_criteria {
+ my ($self, $order_by, $sql_maker) = @_;
+
+ my $parser = sub {
+ my ($sql_maker, $order_by) = @_;
+
+ return scalar $sql_maker->_order_by_chunks ($order_by)
+ unless wantarray;
+
+ my @chunks;
+ for ($sql_maker->_order_by_chunks ($order_by) ) {
+ my $chunk = ref $_ ? $_ : [ $_ ];
+ $chunk->[0] =~ s/\s+ (?: ASC|DESC ) \s* $//ix;
+ push @chunks, $chunk;
+ }
+
+ return @chunks;
+ };
+
+ if ($sql_maker) {
+ return $parser->($sql_maker, $order_by);
+ }
+ else {
+ $sql_maker = $self->sql_maker;
+ local $sql_maker->{quote_char};
+ return $parser->($sql_maker, $order_by);
+ }
+}
1;
projects / dbsrgits/DBIx-Class.git / blobdiff