# make up an order if none exists
my $requested_order = (delete $rs_attrs->{order_by}) || $self->_rno_default_order;
+
+ # the order binds (if any) will need to go at the end of the entire inner select
+ local $self->{order_bind};
my $rno_ord = $self->_order_by ($requested_order);
+ push @{$self->{select_bind}}, @{$self->{order_bind}};
# this is the order supplement magic
my $mid_sel = $sq_attrs->{selection_outer};
}
# and this is order re-alias magic
- for ($sq_attrs->{order_supplement}, $sq_attrs->{outer_renames}) {
- for my $col (keys %$_) {
+ for my $map ($sq_attrs->{order_supplement}, $sq_attrs->{outer_renames}) {
+ for my $col (sort { (length $b) <=> (length $a) } keys %{$map||{}} ) {
my $re_col = quotemeta ($col);
- $rno_ord =~ s/$re_col/$_->{$col}/;
+ $rno_ord =~ s/$re_col/$map->{$col}/;
}
}
$rs_attrs->{order_by}
and
$rs_attrs->{_rsroot_rsrc}->storage->_order_by_is_stable(
- $rs_attrs->{from}, $rs_attrs->{order_by}
+ @{$rs_attrs}{qw/from order_by where/}
)
) {
push @{$self->{limit_bind}}, [ $self->__total_bindtype => $offset + $rows ], [ $self->__offset_bindtype => $offset + 1 ];
$sq_attrs->{order_by_requested} = $self->_order_by ($requested_order);
$sq_attrs->{grpby_having} = $self->_parse_rs_attrs ($rs_attrs);
- # make up an order unless supplied or sanity check what we are given
- my $inner_order;
- if ($sq_attrs->{order_by_requested}) {
- $self->throw_exception (
- 'Unable to safely perform "skimming type" limit with supplied unstable order criteria'
- ) unless $rs_attrs->{_rsroot_rsrc}->schema->storage->_order_by_is_stable(
- $rs_attrs->{from},
- $requested_order
- );
-
- $inner_order = $requested_order;
+ # without an offset things are easy
+ if (! $rs_attrs->{offset}) {
+ $sq_attrs->{order_by_inner} = $sq_attrs->{order_by_requested};
}
else {
- $inner_order = [ map
- { "$rs_attrs->{alias}.$_" }
- ( @{
- $rs_attrs->{_rsroot_rsrc}->_identifying_column_set
- ||
- $self->throw_exception(sprintf(
- 'Unable to auto-construct stable order criteria for "skimming type" limit '
- . "dialect based on source '%s'", $rs_attrs->{_rsroot_rsrc}->name) );
- } )
- ];
- }
-
- # localise as we already have all the bind values we need
- local $self->{order_bind};
-
- $sq_attrs->{order_by_inner} = $self->_order_by ($inner_order);
-
- my @out_chunks;
- for my $ch ($self->_order_by_chunks ($inner_order)) {
- $ch = $ch->[0] if ref $ch eq 'ARRAY';
-
- $ch =~ s/\s+ ( ASC|DESC ) \s* $//ix;
- my $dir = uc ($1||'ASC');
+ $sq_attrs->{quoted_rs_alias} = $self->_quote ($rs_attrs->{alias});
+
+ # localise as we already have all the bind values we need
+ local $self->{order_bind};
+
+ # make up an order unless supplied or sanity check what we are given
+ my $inner_order;
+ if ($sq_attrs->{order_by_requested}) {
+ $self->throw_exception (
+ 'Unable to safely perform "skimming type" limit with supplied unstable order criteria'
+ ) unless ($rs_attrs->{_rsroot_rsrc}->schema->storage->_order_by_is_stable(
+ $rs_attrs->{from},
+ $requested_order,
+ $rs_attrs->{where},
+ ));
+
+ $inner_order = $requested_order;
+ }
+ else {
+ $inner_order = [ map
+ { "$rs_attrs->{alias}.$_" }
+ ( @{
+ $rs_attrs->{_rsroot_rsrc}->_identifying_column_set
+ ||
+ $self->throw_exception(sprintf(
+ 'Unable to auto-construct stable order criteria for "skimming type" limit '
+ . "dialect based on source '%s'", $rs_attrs->{_rsroot_rsrc}->name) );
+ } )
+ ];
+ }
- push @out_chunks, \join (' ', $ch, $dir eq 'ASC' ? 'DESC' : 'ASC' );
- }
+ $sq_attrs->{order_by_inner} = $self->_order_by ($inner_order);
- $sq_attrs->{quoted_rs_alias} = $self->_quote ($rs_attrs->{alias});
- $sq_attrs->{order_by_middle} = $self->_order_by (\@out_chunks);
- $sq_attrs->{selection_middle} = $sq_attrs->{selection_outer};
+ my @out_chunks;
+ for my $ch ($self->_order_by_chunks ($inner_order)) {
+ $ch = $ch->[0] if ref $ch eq 'ARRAY';
- # this is the order supplement magic
- if (my $extra_order_sel = $sq_attrs->{order_supplement}) {
- for my $extra_col (sort
- { $extra_order_sel->{$a} cmp $extra_order_sel->{$b} }
- keys %$extra_order_sel
- ) {
- $sq_attrs->{selection_inner} .= sprintf (', %s AS %s',
- $extra_col,
- $extra_order_sel->{$extra_col},
- );
-
- $sq_attrs->{selection_middle} .= ', ' . $extra_order_sel->{$extra_col};
+ $ch =~ s/\s+ ( ASC|DESC ) \s* $//ix;
+ my $dir = uc ($1||'ASC');
+ push @out_chunks, \join (' ', $ch, $dir eq 'ASC' ? 'DESC' : 'ASC' );
}
- # Whatever order bindvals there are, they will be realiased and
- # reselected, and need to show up at end of the initial inner select
- push @{$self->{select_bind}}, @{$self->{order_bind}};
-
- # if this is a part of something bigger, we need to add back all
- # the extra order_by's, as they may be relied upon by the outside
- # of a prefetch or something
- if ($rs_attrs->{_is_internal_subuery}) {
- $sq_attrs->{selection_outer} .= sprintf ", $extra_order_sel->{$_} AS $_"
- for sort
- { $extra_order_sel->{$a} cmp $extra_order_sel->{$b} }
- grep { $_ !~ /[^\w\-]/ } # ignore functions
- keys %$extra_order_sel
- ;
+ $sq_attrs->{order_by_middle} = $self->_order_by (\@out_chunks);
+
+ # this is the order supplement magic
+ $sq_attrs->{selection_middle} = $sq_attrs->{selection_outer};
+ if (my $extra_order_sel = $sq_attrs->{order_supplement}) {
+ for my $extra_col (sort
+ { $extra_order_sel->{$a} cmp $extra_order_sel->{$b} }
+ keys %$extra_order_sel
+ ) {
+ $sq_attrs->{selection_inner} .= sprintf (', %s AS %s',
+ $extra_col,
+ $extra_order_sel->{$extra_col},
+ );
+
+ $sq_attrs->{selection_middle} .= ', ' . $extra_order_sel->{$extra_col};
+ }
+
+ # Whatever order bindvals there are, they will be realiased and
+ # reselected, and need to show up at end of the initial inner select
+ push @{$self->{select_bind}}, @{$self->{order_bind}};
+
+ # if this is a part of something bigger, we need to add back all
+ # the extra order_by's, as they may be relied upon by the outside
+ # of a prefetch or something
+ if ($rs_attrs->{_is_internal_subuery}) {
+ $sq_attrs->{selection_outer} .= sprintf ", $extra_order_sel->{$_} AS $_"
+ for sort
+ { $extra_order_sel->{$a} cmp $extra_order_sel->{$b} }
+ grep { $_ !~ /[^\w\-]/ } # ignore functions
+ keys %$extra_order_sel
+ ;
+ }
}
- }
- # and this is order re-alias magic
- for my $map ($sq_attrs->{order_supplement}, $sq_attrs->{outer_renames}) {
- for my $col (sort { $map->{$a} cmp $map->{$b} } keys %{$map||{}}) {
- my $re_col = quotemeta ($col);
- $_ =~ s/$re_col/$map->{$col}/
- for ($sq_attrs->{order_by_middle}, $sq_attrs->{order_by_requested});
+ # and this is order re-alias magic
+ for my $map ($sq_attrs->{order_supplement}, $sq_attrs->{outer_renames}) {
+ for my $col (sort { (length $b) <=> (length $a) } keys %{$map||{}}) {
+ my $re_col = quotemeta ($col);
+ $_ =~ s/$re_col/$map->{$col}/
+ for ($sq_attrs->{order_by_middle}, $sq_attrs->{order_by_requested});
+ }
}
}
$sql = sprintf ('SELECT TOP %u %s %s %s %s',
$rows + ($offset||0),
- $lim->{selection_inner},
+ $offset ? $lim->{selection_inner} : $lim->{selection_original},
$lim->{query_leftover},
$lim->{grpby_having},
$lim->{order_by_inner},
$lim->{order_by_middle},
) if $offset;
- $sql = sprintf ('SELECT TOP %u %s FROM ( %s ) %s %s',
- $rows,
+ $sql = sprintf ('SELECT %s FROM ( %s ) %s %s',
$lim->{selection_outer},
$sql,
$lim->{quoted_rs_alias},
my $lim = $self->_prep_for_skimming_limit($sql, $rs_attrs);
$sql = sprintf ('SELECT %s %s %s %s FETCH FIRST %u ROWS ONLY',
- $lim->{selection_inner},
+ $offset ? $lim->{selection_inner} : $lim->{selection_original},
$lim->{query_leftover},
$lim->{grpby_having},
$lim->{order_by_inner},
) if $offset;
- $sql = sprintf ('SELECT %s FROM ( %s ) %s %s FETCH FIRST %u ROWS ONLY',
+ $sql = sprintf ('SELECT %s FROM ( %s ) %s %s',
$lim->{selection_outer},
$sql,
$lim->{quoted_rs_alias},
$lim->{order_by_requested},
- $rows,
) if $offset and (
$lim->{order_by_requested} or $lim->{selection_middle} ne $lim->{selection_outer}
);
return $self->_GenericSubQ(@_) if $offset;
- return sprintf <<"EOF", $rows, $sql;
+ return sprintf <<"EOF", $rows, $sql, $self->_parse_rs_attrs( $rs_attrs );
SET ROWCOUNT %d
-%s
+%s %s
SET ROWCOUNT 0
EOF
}
databases. It works by ordering the set by some unique column, and calculating
the amount of rows that have a less-er value (thus emulating a L</RowNum>-like
index). Of course this implies the set can only be ordered by a single unique
-column. Also note that this technique can be and often is B<excruciatingly
-slow>.
+column.
+
+Also note that this technique can be and often is B<excruciatingly slow>. You
+may have much better luck using L<DBIx::Class::ResultSet/software_limit>
+instead.
Currently used by B<Sybase ASE>, due to lack of any other option.
my ($first_order_by) = do {
local $self->{quote_char};
+ local $self->{order_bind};
map { ref $_ ? $_->[0] : $_ } $self->_order_by_chunks ($rs_attrs->{order_by})
} or $self->throw_exception (
'Generic Subquery Limit does not work on resultsets without an order. Provide a single, '
"Generic Subquery Limit first order criteria '$first_ord_col' must be unique"
) unless $root_rsrc->_identifying_column_set([$first_ord_col]);
- my $sq_attrs = $self->_subqueried_limit_attrs ($sql, $rs_attrs);
+ my $sq_attrs = do {
+ # perform the mangling only using the very first order crietria
+ # (the one we care about)
+ local $rs_attrs->{order_by} = $first_order_by;
+ $self->_subqueried_limit_attrs ($sql, $rs_attrs);
+ };
my $cmp_op = $direction eq 'desc' ? '>' : '<';
my $count_tbl_alias = 'rownum__emulation';
- my $order_sql = $self->_order_by (delete $rs_attrs->{order_by});
+ my ($order_sql, @order_bind) = do {
+ local $self->{order_bind};
+ my $s = $self->_order_by (delete $rs_attrs->{order_by});
+ ($s, @{$self->{order_bind}});
+ };
my $group_having_sql = $self->_parse_rs_attrs($rs_attrs);
my $in_sel = $sq_attrs->{selection_inner};
;
}
+ # even though binds in order_by make no sense here (the rs needs to be
+ # ordered by a unique column first) - pass whatever there may be through
+ # anyway
+ push @{$self->{limit_bind}}, @order_bind;
+
return sprintf ("
SELECT $sq_attrs->{selection_outer}
FROM (
my $sql_alias = (ref $s) eq 'HASH' ? $s->{-as} : undef;
push @sel, {
+ arg => $s,
sql => $sql_sel,
unquoted_sql => do {
local $self->{quote_char};
,
};
- $in_sel_index->{$sql_sel}++;
+ # anything with a placeholder in it needs re-selection
+ $in_sel_index->{$sql_sel}++ unless $sql_sel =~ / (?: ^ | \W ) \? (?: \W | $ ) /x;
+
$in_sel_index->{$self->_quote ($sql_alias)}++ if $sql_alias;
# record unqualified versions too, so we do not have
# unless we are dealing with the current source alias
# (which will transcend the subqueries as it is necessary
# for possible further chaining)
+ # same for anything we do not recognize
my ($sel, $renamed);
for my $node (@sel) {
+ push @{$sel->{original}}, $node->{sql};
+
if (
+ ! $in_sel_index->{$node->{sql}}
+ or
$node->{as} =~ / (?<! ^ $re_alias ) \. /x
or
$node->{unquoted_sql} =~ / (?<! ^ $re_alias ) $re_sep /x
}
else {
push @{$sel->{inner}}, $node->{sql};
- push @{$sel->{outer}}, $self->_quote ($node->{as});
+ push @{$sel->{outer}}, $self->_quote (ref $node->{arg} ? $node->{as} : $node->{arg});
}
}