Commit | Line | Data |
c443438f |
1 | package #hide from PAUSE |
2 | DBIx::Class::Storage::DBIHacks; |
d28bb90d |
3 | |
4 | # |
5 | # This module contains code that should never have seen the light of day, |
6 | # does not belong in the Storage, or is otherwise unfit for public |
7eb76996 |
7 | # display. The arrival of SQLA2 should immediately oboslete 90% of this |
d28bb90d |
8 | # |
9 | |
10 | use strict; |
11 | use warnings; |
12 | |
13 | use base 'DBIx::Class::Storage'; |
14 | use mro 'c3'; |
15 | |
16 | use Carp::Clan qw/^DBIx::Class/; |
6298a324 |
17 | use List::Util 'first'; |
18 | use Scalar::Util 'blessed'; |
19 | use namespace::clean; |
d28bb90d |
20 | |
21 | # |
052e8431 |
22 | # This code will remove non-selecting/non-restricting joins from |
4b1b5ea3 |
23 | # {from} specs, aiding the RDBMS query optimizer |
052e8431 |
24 | # |
25 | sub _prune_unused_joins { |
ea95892e |
26 | my $self = shift; |
4b1b5ea3 |
27 | my ($from, $select, $where, $attrs) = @_; |
052e8431 |
28 | |
ea95892e |
29 | return $from unless $self->_use_join_optimizer; |
30 | |
052e8431 |
31 | if (ref $from ne 'ARRAY' || ref $from->[0] ne 'HASH' || ref $from->[1] ne 'ARRAY') { |
32 | return $from; # only standard {from} specs are supported |
33 | } |
34 | |
4b1b5ea3 |
35 | my $aliastypes = $self->_resolve_aliastypes_from_select_args(@_); |
36 | |
37 | # a grouped set will not be affected by amount of rows. Thus any |
38 | # {multiplying} joins can go |
39 | delete $aliastypes->{multiplying} if $attrs->{group_by}; |
40 | |
052e8431 |
41 | my @newfrom = $from->[0]; # FROM head is always present |
42 | |
43 | my %need_joins = (map { %{$_||{}} } (values %$aliastypes) ); |
44 | for my $j (@{$from}[1..$#$from]) { |
539ffe87 |
45 | push @newfrom, $j if ( |
4b1b5ea3 |
46 | (! $j->[0]{-alias}) # legacy crap |
539ffe87 |
47 | || |
48 | $need_joins{$j->[0]{-alias}} |
49 | ); |
052e8431 |
50 | } |
51 | |
52 | return \@newfrom; |
53 | } |
54 | |
052e8431 |
55 | # |
d28bb90d |
56 | # This is the code producing joined subqueries like: |
57 | # SELECT me.*, other.* FROM ( SELECT me.* FROM ... ) JOIN other ON ... |
58 | # |
59 | sub _adjust_select_args_for_complex_prefetch { |
60 | my ($self, $from, $select, $where, $attrs) = @_; |
61 | |
62 | $self->throw_exception ('Nothing to prefetch... how did we get here?!') |
36fd7f07 |
63 | if not @{$attrs->{_prefetch_selector_range}}; |
d28bb90d |
64 | |
65 | $self->throw_exception ('Complex prefetches are not supported on resultsets with a custom from attribute') |
66 | if (ref $from ne 'ARRAY' || ref $from->[0] ne 'HASH' || ref $from->[1] ne 'ARRAY'); |
67 | |
68 | |
69 | # generate inner/outer attribute lists, remove stuff that doesn't apply |
70 | my $outer_attrs = { %$attrs }; |
71 | delete $outer_attrs->{$_} for qw/where bind rows offset group_by having/; |
72 | |
73 | my $inner_attrs = { %$attrs }; |
36fd7f07 |
74 | delete $inner_attrs->{$_} for qw/for collapse _prefetch_selector_range _collapse_order_by select as/; |
d28bb90d |
75 | |
76 | |
77 | # bring over all non-collapse-induced order_by into the inner query (if any) |
78 | # the outer one will have to keep them all |
79 | delete $inner_attrs->{order_by}; |
80 | if (my $ord_cnt = @{$outer_attrs->{order_by}} - @{$outer_attrs->{_collapse_order_by}} ) { |
81 | $inner_attrs->{order_by} = [ |
82 | @{$outer_attrs->{order_by}}[ 0 .. $ord_cnt - 1] |
83 | ]; |
84 | } |
85 | |
d28bb90d |
86 | # generate the inner/outer select lists |
87 | # for inside we consider only stuff *not* brought in by the prefetch |
88 | # on the outside we substitute any function for its alias |
89 | my $outer_select = [ @$select ]; |
90 | my $inner_select = []; |
36fd7f07 |
91 | |
92 | my ($p_start, $p_end) = @{$outer_attrs->{_prefetch_selector_range}}; |
93 | for my $i (0 .. $p_start - 1, $p_end + 1 .. $#$outer_select) { |
d28bb90d |
94 | my $sel = $outer_select->[$i]; |
95 | |
96 | if (ref $sel eq 'HASH' ) { |
97 | $sel->{-as} ||= $attrs->{as}[$i]; |
98 | $outer_select->[$i] = join ('.', $attrs->{alias}, ($sel->{-as} || "inner_column_$i") ); |
99 | } |
100 | |
101 | push @$inner_select, $sel; |
bb9bffea |
102 | |
103 | push @{$inner_attrs->{as}}, $attrs->{as}[$i]; |
d28bb90d |
104 | } |
105 | |
ea95892e |
106 | # construct the inner $from and lock it in a subquery |
48580715 |
107 | # we need to prune first, because this will determine if we need a group_by below |
53c29913 |
108 | # the fake group_by is so that the pruner throws away all non-selecting, non-restricting |
109 | # multijoins (since we def. do not care about those inside the subquery) |
ea95892e |
110 | |
111 | my $subq_joinspec = do { |
112 | |
113 | # must use it here regardless of user requests |
114 | local $self->{_use_join_optimizer} = 1; |
115 | |
116 | my $inner_from = $self->_prune_unused_joins ($from, $inner_select, $where, { |
117 | group_by => ['dummy'], %$inner_attrs, |
118 | }); |
119 | |
887a0aef |
120 | my $inner_aliastypes = |
121 | $self->_resolve_aliastypes_from_select_args( $inner_from, $inner_select, $where, $inner_attrs ); |
122 | |
123 | # if a multi-type non-selecting (only restricting) join was needed in the subquery |
124 | # add a group_by to simulate the collapse in the subq |
0a3441ee |
125 | if ( |
126 | ! $inner_attrs->{group_by} |
127 | and |
887a0aef |
128 | first { |
129 | $inner_aliastypes->{restricting}{$_} |
130 | and |
131 | ! $inner_aliastypes->{selecting}{$_} |
132 | } ( keys %{$inner_aliastypes->{multiplying}||{}} ) |
0a3441ee |
133 | ) { |
14e26c5f |
134 | my $unprocessed_order_chunks; |
135 | ($inner_attrs->{group_by}, $unprocessed_order_chunks) = $self->_group_over_selection ( |
0a3441ee |
136 | $inner_from, $inner_select, $inner_attrs->{order_by} |
137 | ); |
14e26c5f |
138 | |
139 | $self->throw_exception ( |
140 | 'A required group_by clause could not be constructed automatically due to a complex ' |
141 | . 'order_by criteria. Either order_by columns only (no functions) or construct a suitable ' |
142 | . 'group_by by hand' |
143 | ) if $unprocessed_order_chunks; |
0a3441ee |
144 | } |
ea95892e |
145 | |
146 | # we already optimized $inner_from above |
147 | local $self->{_use_join_optimizer} = 0; |
148 | |
149 | # generate the subquery |
150 | my $subq = $self->_select_args_to_query ( |
151 | $inner_from, |
152 | $inner_select, |
153 | $where, |
154 | $inner_attrs, |
155 | ); |
156 | |
157 | +{ |
158 | -alias => $attrs->{alias}, |
4376a157 |
159 | -rsrc => $inner_from->[0]{-rsrc}, |
ea95892e |
160 | $attrs->{alias} => $subq, |
161 | }; |
d28bb90d |
162 | }; |
163 | |
164 | # Generate the outer from - this is relatively easy (really just replace |
165 | # the join slot with the subquery), with a major caveat - we can not |
166 | # join anything that is non-selecting (not part of the prefetch), but at |
167 | # the same time is a multi-type relationship, as it will explode the result. |
168 | # |
169 | # There are two possibilities here |
170 | # - either the join is non-restricting, in which case we simply throw it away |
171 | # - it is part of the restrictions, in which case we need to collapse the outer |
172 | # result by tackling yet another group_by to the outside of the query |
173 | |
052e8431 |
174 | $from = [ @$from ]; |
052e8431 |
175 | |
d28bb90d |
176 | # so first generate the outer_from, up to the substitution point |
177 | my @outer_from; |
178 | while (my $j = shift @$from) { |
53c29913 |
179 | $j = [ $j ] unless ref $j eq 'ARRAY'; # promote the head-from to an AoH |
180 | |
d28bb90d |
181 | if ($j->[0]{-alias} eq $attrs->{alias}) { # time to swap |
182 | push @outer_from, [ |
183 | $subq_joinspec, |
184 | @{$j}[1 .. $#$j], |
185 | ]; |
186 | last; # we'll take care of what's left in $from below |
187 | } |
188 | else { |
189 | push @outer_from, $j; |
190 | } |
191 | } |
192 | |
ea95892e |
193 | # scan the *remaining* from spec against different attributes, and see which joins are needed |
052e8431 |
194 | # in what role |
195 | my $outer_aliastypes = |
539ffe87 |
196 | $self->_resolve_aliastypes_from_select_args( $from, $outer_select, $where, $outer_attrs ); |
052e8431 |
197 | |
d28bb90d |
198 | # see what's left - throw away if not selecting/restricting |
199 | # also throw in a group_by if restricting to guard against |
200 | # cross-join explosions |
201 | # |
36fd7f07 |
202 | my $need_outer_group_by; |
d28bb90d |
203 | while (my $j = shift @$from) { |
204 | my $alias = $j->[0]{-alias}; |
205 | |
1a736efb |
206 | if ($outer_aliastypes->{selecting}{$alias}) { |
d28bb90d |
207 | push @outer_from, $j; |
208 | } |
1a736efb |
209 | elsif ($outer_aliastypes->{restricting}{$alias}) { |
d28bb90d |
210 | push @outer_from, $j; |
36fd7f07 |
211 | $need_outer_group_by ||= ! $j->[0]{-is_single}; |
d28bb90d |
212 | } |
213 | } |
214 | |
215 | # demote the outer_from head |
216 | $outer_from[0] = $outer_from[0][0]; |
217 | |
36fd7f07 |
218 | if ($need_outer_group_by and ! $outer_attrs->{group_by}) { |
219 | |
220 | my $unprocessed_order_chunks; |
221 | ($outer_attrs->{group_by}, $unprocessed_order_chunks) = $self->_group_over_selection ( |
222 | \@outer_from, $outer_select, $outer_attrs->{order_by} |
223 | ); |
224 | |
225 | $self->throw_exception ( |
226 | 'A required group_by clause could not be constructed automatically due to a complex ' |
227 | . 'order_by criteria. Either order_by columns only (no functions) or construct a suitable ' |
228 | . 'group_by by hand' |
229 | ) if $unprocessed_order_chunks; |
230 | |
231 | } |
232 | |
d28bb90d |
233 | # This is totally horrific - the $where ends up in both the inner and outer query |
234 | # Unfortunately not much can be done until SQLA2 introspection arrives, and even |
235 | # then if where conditions apply to the *right* side of the prefetch, you may have |
236 | # to both filter the inner select (e.g. to apply a limit) and then have to re-filter |
237 | # the outer select to exclude joins you didin't want in the first place |
238 | # |
239 | # OTOH it can be seen as a plus: <ash> (notes that this query would make a DBA cry ;) |
240 | return (\@outer_from, $outer_select, $where, $outer_attrs); |
241 | } |
242 | |
1a736efb |
243 | # |
244 | # I KNOW THIS SUCKS! GET SQLA2 OUT THE DOOR SO THIS CAN DIE! |
245 | # |
ad630f4b |
246 | # Due to a lack of SQLA2 we fall back to crude scans of all the |
247 | # select/where/order/group attributes, in order to determine what |
248 | # aliases are neded to fulfill the query. This information is used |
249 | # throughout the code to prune unnecessary JOINs from the queries |
250 | # in an attempt to reduce the execution time. |
251 | # Although the method is pretty horrific, the worst thing that can |
1a736efb |
252 | # happen is for it to fail due to some scalar SQL, which in turn will |
253 | # result in a vocal exception. |
539ffe87 |
254 | sub _resolve_aliastypes_from_select_args { |
052e8431 |
255 | my ( $self, $from, $select, $where, $attrs ) = @_; |
546f1cd9 |
256 | |
ad630f4b |
257 | $self->throw_exception ('Unable to analyze custom {from}') |
258 | if ref $from ne 'ARRAY'; |
546f1cd9 |
259 | |
ad630f4b |
260 | # what we will return |
964a3c71 |
261 | my $aliases_by_type; |
546f1cd9 |
262 | |
ad630f4b |
263 | # see what aliases are there to work with |
264 | my $alias_list; |
539ffe87 |
265 | for (@$from) { |
266 | my $j = $_; |
ad630f4b |
267 | $j = $j->[0] if ref $j eq 'ARRAY'; |
539ffe87 |
268 | my $al = $j->{-alias} |
269 | or next; |
270 | |
271 | $alias_list->{$al} = $j; |
272 | $aliases_by_type->{multiplying}{$al} = 1 |
53c29913 |
273 | if ref($_) eq 'ARRAY' and ! $j->{-is_single}; # not array == {from} head == can't be multiplying |
546f1cd9 |
274 | } |
546f1cd9 |
275 | |
1a736efb |
276 | # get a column to source/alias map (including unqualified ones) |
277 | my $colinfo = $self->_resolve_column_info ($from); |
278 | |
ad630f4b |
279 | # set up a botched SQLA |
280 | my $sql_maker = $self->sql_maker; |
07f31d19 |
281 | |
4c2b30d6 |
282 | # these are throw away results, do not pollute the bind stack |
4c2b30d6 |
283 | local $sql_maker->{select_bind}; |
0542ec57 |
284 | local $sql_maker->{where_bind}; |
285 | local $sql_maker->{group_bind}; |
286 | local $sql_maker->{having_bind}; |
3f5b99fe |
287 | |
288 | # we can't scan properly without any quoting (\b doesn't cut it |
289 | # everywhere), so unless there is proper quoting set - use our |
290 | # own weird impossible character. |
291 | # Also in the case of no quoting, we need to explicitly disable |
292 | # name_sep, otherwise sorry nasty legacy syntax like |
293 | # { 'count(foo.id)' => { '>' => 3 } } will stop working >:( |
294 | local $sql_maker->{quote_char} = $sql_maker->{quote_char}; |
295 | local $sql_maker->{name_sep} = $sql_maker->{name_sep}; |
296 | |
297 | unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) { |
e493ecb2 |
298 | $sql_maker->{quote_char} = ["\x00", "\xFF"]; |
299 | # if we don't unset it we screw up retarded but unfortunately working |
300 | # 'MAX(foo.bar)' => { '>', 3 } |
3f5b99fe |
301 | $sql_maker->{name_sep} = ''; |
302 | } |
303 | |
304 | my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep); |
07f31d19 |
305 | |
1a736efb |
306 | # generate sql chunks |
307 | my $to_scan = { |
308 | restricting => [ |
309 | $sql_maker->_recurse_where ($where), |
a7e643b1 |
310 | $sql_maker->_parse_rs_attrs ({ |
1a736efb |
311 | map { $_ => $attrs->{$_} } (qw/group_by having/) |
312 | }), |
313 | ], |
314 | selecting => [ |
1a736efb |
315 | $sql_maker->_recurse_fields ($select), |
bac358c9 |
316 | ( map { $_->[0] } $self->_extract_order_criteria ($attrs->{order_by}, $sql_maker) ), |
1a736efb |
317 | ], |
318 | }; |
319 | |
320 | # throw away empty chunks |
321 | $_ = [ map { $_ || () } @$_ ] for values %$to_scan; |
322 | |
323 | # first loop through all fully qualified columns and get the corresponding |
324 | # alias (should work even if they are in scalarrefs) |
ad630f4b |
325 | for my $alias (keys %$alias_list) { |
1a736efb |
326 | my $al_re = qr/ |
3f5b99fe |
327 | $lquote $alias $rquote $sep |
1a736efb |
328 | | |
3f5b99fe |
329 | \b $alias \. |
1a736efb |
330 | /x; |
331 | |
1a736efb |
332 | for my $type (keys %$to_scan) { |
333 | for my $piece (@{$to_scan->{$type}}) { |
334 | $aliases_by_type->{$type}{$alias} = 1 if ($piece =~ $al_re); |
335 | } |
ad630f4b |
336 | } |
1a736efb |
337 | } |
338 | |
339 | # now loop through unqualified column names, and try to locate them within |
340 | # the chunks |
341 | for my $col (keys %$colinfo) { |
3f5b99fe |
342 | next if $col =~ / \. /x; # if column is qualified it was caught by the above |
1a736efb |
343 | |
3f5b99fe |
344 | my $col_re = qr/ $lquote $col $rquote /x; |
1a736efb |
345 | |
346 | for my $type (keys %$to_scan) { |
347 | for my $piece (@{$to_scan->{$type}}) { |
348 | $aliases_by_type->{$type}{$colinfo->{$col}{-source_alias}} = 1 if ($piece =~ $col_re); |
349 | } |
07f31d19 |
350 | } |
351 | } |
352 | |
353 | # Add any non-left joins to the restriction list (such joins are indeed restrictions) |
ad630f4b |
354 | for my $j (values %$alias_list) { |
07f31d19 |
355 | my $alias = $j->{-alias} or next; |
1a736efb |
356 | $aliases_by_type->{restricting}{$alias} = 1 if ( |
07f31d19 |
357 | (not $j->{-join_type}) |
358 | or |
359 | ($j->{-join_type} !~ /^left (?: \s+ outer)? $/xi) |
360 | ); |
361 | } |
362 | |
ea95892e |
363 | # mark all restricting/selecting join parents as such |
07f31d19 |
364 | # (e.g. join => { cds => 'tracks' } - tracks will need to bring cds too ) |
ea95892e |
365 | for my $type (qw/restricting selecting/) { |
366 | for my $alias (keys %{$aliases_by_type->{$type}||{}}) { |
964a3c71 |
367 | $aliases_by_type->{$type}{$_} = 1 |
faeb2407 |
368 | for (map { values %$_ } @{ $alias_list->{$alias}{-join_path} || [] }); |
07f31d19 |
369 | } |
370 | } |
ad630f4b |
371 | |
964a3c71 |
372 | return $aliases_by_type; |
07f31d19 |
373 | } |
374 | |
bac358c9 |
375 | # This is the engine behind { distinct => 1 } |
0a3441ee |
376 | sub _group_over_selection { |
377 | my ($self, $from, $select, $order_by) = @_; |
378 | |
379 | my $rs_column_list = $self->_resolve_column_info ($from); |
380 | |
381 | my (@group_by, %group_index); |
382 | |
36fd7f07 |
383 | # the logic is: if it is a { func => val } we assume an aggregate, |
384 | # otherwise if \'...' or \[...] we assume the user knows what is |
385 | # going on thus group over it |
0a3441ee |
386 | for (@$select) { |
387 | if (! ref($_) or ref ($_) ne 'HASH' ) { |
388 | push @group_by, $_; |
389 | $group_index{$_}++; |
390 | if ($rs_column_list->{$_} and $_ !~ /\./ ) { |
391 | # add a fully qualified version as well |
392 | $group_index{"$rs_column_list->{$_}{-source_alias}.$_"}++; |
393 | } |
394 | } |
395 | } |
396 | |
397 | # add any order_by parts that are not already present in the group_by |
398 | # we need to be careful not to add any named functions/aggregates |
bac358c9 |
399 | # i.e. order_by => [ ... { count => 'foo' } ... ] |
14e26c5f |
400 | my @leftovers; |
bac358c9 |
401 | for ($self->_extract_order_criteria($order_by)) { |
0a3441ee |
402 | # only consider real columns (for functions the user got to do an explicit group_by) |
14e26c5f |
403 | if (@$_ != 1) { |
404 | push @leftovers, $_; |
405 | next; |
406 | } |
bac358c9 |
407 | my $chunk = $_->[0]; |
14e26c5f |
408 | my $colinfo = $rs_column_list->{$chunk} or do { |
409 | push @leftovers, $_; |
410 | next; |
411 | }; |
0a3441ee |
412 | |
413 | $chunk = "$colinfo->{-source_alias}.$chunk" if $chunk !~ /\./; |
414 | push @group_by, $chunk unless $group_index{$chunk}++; |
415 | } |
416 | |
14e26c5f |
417 | return wantarray |
418 | ? (\@group_by, (@leftovers ? \@leftovers : undef) ) |
419 | : \@group_by |
420 | ; |
0a3441ee |
421 | } |
422 | |
d28bb90d |
423 | sub _resolve_ident_sources { |
424 | my ($self, $ident) = @_; |
425 | |
426 | my $alias2source = {}; |
427 | my $rs_alias; |
428 | |
429 | # the reason this is so contrived is that $ident may be a {from} |
430 | # structure, specifying multiple tables to join |
6298a324 |
431 | if ( blessed $ident && $ident->isa("DBIx::Class::ResultSource") ) { |
d28bb90d |
432 | # this is compat mode for insert/update/delete which do not deal with aliases |
433 | $alias2source->{me} = $ident; |
434 | $rs_alias = 'me'; |
435 | } |
436 | elsif (ref $ident eq 'ARRAY') { |
437 | |
438 | for (@$ident) { |
439 | my $tabinfo; |
440 | if (ref $_ eq 'HASH') { |
441 | $tabinfo = $_; |
442 | $rs_alias = $tabinfo->{-alias}; |
443 | } |
444 | if (ref $_ eq 'ARRAY' and ref $_->[0] eq 'HASH') { |
445 | $tabinfo = $_->[0]; |
446 | } |
447 | |
4376a157 |
448 | $alias2source->{$tabinfo->{-alias}} = $tabinfo->{-rsrc} |
449 | if ($tabinfo->{-rsrc}); |
d28bb90d |
450 | } |
451 | } |
452 | |
453 | return ($alias2source, $rs_alias); |
454 | } |
455 | |
456 | # Takes $ident, \@column_names |
457 | # |
458 | # returns { $column_name => \%column_info, ... } |
459 | # also note: this adds -result_source => $rsrc to the column info |
460 | # |
09e14fdc |
461 | # If no columns_names are supplied returns info about *all* columns |
462 | # for all sources |
d28bb90d |
463 | sub _resolve_column_info { |
464 | my ($self, $ident, $colnames) = @_; |
465 | my ($alias2src, $root_alias) = $self->_resolve_ident_sources($ident); |
466 | |
52416317 |
467 | my (%seen_cols, @auto_colnames); |
d28bb90d |
468 | |
469 | # compile a global list of column names, to be able to properly |
470 | # disambiguate unqualified column names (if at all possible) |
471 | for my $alias (keys %$alias2src) { |
472 | my $rsrc = $alias2src->{$alias}; |
473 | for my $colname ($rsrc->columns) { |
474 | push @{$seen_cols{$colname}}, $alias; |
3f5b99fe |
475 | push @auto_colnames, "$alias.$colname" unless $colnames; |
d28bb90d |
476 | } |
477 | } |
478 | |
09e14fdc |
479 | $colnames ||= [ |
480 | @auto_colnames, |
481 | grep { @{$seen_cols{$_}} == 1 } (keys %seen_cols), |
482 | ]; |
483 | |
52416317 |
484 | my (%return, $colinfos); |
d28bb90d |
485 | foreach my $col (@$colnames) { |
52416317 |
486 | my ($source_alias, $colname) = $col =~ m/^ (?: ([^\.]+) \. )? (.+) $/x; |
d28bb90d |
487 | |
52416317 |
488 | # if the column was seen exactly once - we know which rsrc it came from |
489 | $source_alias ||= $seen_cols{$colname}[0] |
490 | if ($seen_cols{$colname} and @{$seen_cols{$colname}} == 1); |
d28bb90d |
491 | |
52416317 |
492 | next unless $source_alias; |
493 | |
494 | my $rsrc = $alias2src->{$source_alias} |
495 | or next; |
496 | |
497 | $return{$col} = { |
498 | %{ ( $colinfos->{$source_alias} ||= $rsrc->columns_info )->{$colname} }, |
d28bb90d |
499 | -result_source => $rsrc, |
52416317 |
500 | -source_alias => $source_alias, |
d28bb90d |
501 | }; |
502 | } |
503 | |
504 | return \%return; |
505 | } |
506 | |
289ac713 |
507 | # The DBIC relationship chaining implementation is pretty simple - every |
508 | # new related_relationship is pushed onto the {from} stack, and the {select} |
509 | # window simply slides further in. This means that when we count somewhere |
510 | # in the middle, we got to make sure that everything in the join chain is an |
511 | # actual inner join, otherwise the count will come back with unpredictable |
512 | # results (a resultset may be generated with _some_ rows regardless of if |
513 | # the relation which the $rs currently selects has rows or not). E.g. |
514 | # $artist_rs->cds->count - normally generates: |
515 | # SELECT COUNT( * ) FROM artist me LEFT JOIN cd cds ON cds.artist = me.artistid |
516 | # which actually returns the number of artists * (number of cds || 1) |
517 | # |
518 | # So what we do here is crawl {from}, determine if the current alias is at |
519 | # the top of the stack, and if not - make sure the chain is inner-joined down |
520 | # to the root. |
521 | # |
31a8aaaf |
522 | sub _inner_join_to_node { |
289ac713 |
523 | my ($self, $from, $alias) = @_; |
524 | |
525 | # subqueries and other oddness are naturally not supported |
526 | return $from if ( |
527 | ref $from ne 'ARRAY' |
528 | || |
529 | @$from <= 1 |
530 | || |
531 | ref $from->[0] ne 'HASH' |
532 | || |
533 | ! $from->[0]{-alias} |
534 | || |
7eb76996 |
535 | $from->[0]{-alias} eq $alias # this last bit means $alias is the head of $from - nothing to do |
289ac713 |
536 | ); |
537 | |
538 | # find the current $alias in the $from structure |
539 | my $switch_branch; |
540 | JOINSCAN: |
541 | for my $j (@{$from}[1 .. $#$from]) { |
542 | if ($j->[0]{-alias} eq $alias) { |
543 | $switch_branch = $j->[0]{-join_path}; |
544 | last JOINSCAN; |
545 | } |
546 | } |
547 | |
7eb76996 |
548 | # something else went quite wrong |
289ac713 |
549 | return $from unless $switch_branch; |
550 | |
551 | # So it looks like we will have to switch some stuff around. |
552 | # local() is useless here as we will be leaving the scope |
553 | # anyway, and deep cloning is just too fucking expensive |
7eb76996 |
554 | # So replace the first hashref in the node arrayref manually |
289ac713 |
555 | my @new_from = ($from->[0]); |
faeb2407 |
556 | my $sw_idx = { map { (values %$_), 1 } @$switch_branch }; #there's one k/v per join-path |
289ac713 |
557 | |
558 | for my $j (@{$from}[1 .. $#$from]) { |
559 | my $jalias = $j->[0]{-alias}; |
560 | |
561 | if ($sw_idx->{$jalias}) { |
562 | my %attrs = %{$j->[0]}; |
563 | delete $attrs{-join_type}; |
564 | push @new_from, [ |
565 | \%attrs, |
566 | @{$j}[ 1 .. $#$j ], |
567 | ]; |
568 | } |
569 | else { |
570 | push @new_from, $j; |
571 | } |
572 | } |
573 | |
574 | return \@new_from; |
575 | } |
576 | |
bac6c4fb |
577 | # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus |
578 | # a condition containing 'me' or other table prefixes will not work |
579 | # at all. What this code tries to do (badly) is introspect the condition |
580 | # and remove all column qualifiers. If it bails out early (returns undef) |
581 | # the calling code should try another approach (e.g. a subquery) |
582 | sub _strip_cond_qualifiers { |
583 | my ($self, $where) = @_; |
584 | |
585 | my $cond = {}; |
586 | |
587 | # No-op. No condition, we're updating/deleting everything |
588 | return $cond unless $where; |
589 | |
590 | if (ref $where eq 'ARRAY') { |
591 | $cond = [ |
592 | map { |
593 | my %hash; |
594 | foreach my $key (keys %{$_}) { |
595 | $key =~ /([^.]+)$/; |
596 | $hash{$1} = $_->{$key}; |
597 | } |
598 | \%hash; |
599 | } @$where |
600 | ]; |
601 | } |
602 | elsif (ref $where eq 'HASH') { |
603 | if ( (keys %$where) == 1 && ( (keys %{$where})[0] eq '-and' )) { |
604 | $cond->{-and} = []; |
605 | my @cond = @{$where->{-and}}; |
606 | for (my $i = 0; $i < @cond; $i++) { |
607 | my $entry = $cond[$i]; |
608 | my $hash; |
037e8dca |
609 | my $ref = ref $entry; |
610 | if ($ref eq 'HASH' or $ref eq 'ARRAY') { |
bac6c4fb |
611 | $hash = $self->_strip_cond_qualifiers($entry); |
612 | } |
037e8dca |
613 | elsif (! $ref) { |
bac6c4fb |
614 | $entry =~ /([^.]+)$/; |
615 | $hash->{$1} = $cond[++$i]; |
616 | } |
037e8dca |
617 | else { |
618 | $self->throw_exception ("_strip_cond_qualifiers() is unable to handle a condition reftype $ref"); |
619 | } |
bac6c4fb |
620 | push @{$cond->{-and}}, $hash; |
621 | } |
622 | } |
623 | else { |
624 | foreach my $key (keys %$where) { |
59ac6523 |
625 | if ($key eq '-or' && ref $where->{$key} eq 'ARRAY') { |
626 | $cond->{$key} = $self->_strip_cond_qualifiers($where->{$key}); |
627 | } |
628 | else { |
629 | $key =~ /([^.]+)$/; |
630 | $cond->{$1} = $where->{$key}; |
631 | } |
bac6c4fb |
632 | } |
633 | } |
634 | } |
635 | else { |
636 | return undef; |
637 | } |
638 | |
639 | return $cond; |
640 | } |
641 | |
bac358c9 |
642 | sub _extract_order_criteria { |
1a736efb |
643 | my ($self, $order_by, $sql_maker) = @_; |
c0748280 |
644 | |
1a736efb |
645 | my $parser = sub { |
646 | my ($sql_maker, $order_by) = @_; |
c0748280 |
647 | |
1a736efb |
648 | return scalar $sql_maker->_order_by_chunks ($order_by) |
649 | unless wantarray; |
c0748280 |
650 | |
1a736efb |
651 | my @chunks; |
bac358c9 |
652 | for ($sql_maker->_order_by_chunks ($order_by) ) { |
653 | my $chunk = ref $_ ? $_ : [ $_ ]; |
654 | $chunk->[0] =~ s/\s+ (?: ASC|DESC ) \s* $//ix; |
1a736efb |
655 | push @chunks, $chunk; |
656 | } |
657 | |
658 | return @chunks; |
659 | }; |
660 | |
661 | if ($sql_maker) { |
662 | return $parser->($sql_maker, $order_by); |
663 | } |
664 | else { |
665 | $sql_maker = $self->sql_maker; |
666 | local $sql_maker->{quote_char}; |
667 | return $parser->($sql_maker, $order_by); |
668 | } |
c0748280 |
669 | } |
bac6c4fb |
670 | |
d28bb90d |
671 | 1; |