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c443438f |
1 | package #hide from PAUSE |
2 | DBIx::Class::Storage::DBIHacks; |
d28bb90d |
3 | |
4 | # |
07fadea8 |
5 | # This module contains code supporting a battery of special cases and tests for |
6 | # many corner cases pushing the envelope of what DBIC can do. When work on |
7 | # these utilities began in mid 2009 (51a296b402c) it wasn't immediately obvious |
8 | # that these pieces, despite their misleading on-first-sighe-flakiness, will |
9 | # become part of the generic query rewriting machinery of DBIC, allowing it to |
10 | # both generate and process queries representing incredibly complex sets with |
11 | # reasonable efficiency. |
12 | # |
13 | # Now (end of 2015), more than 6 years later the routines in this class have |
14 | # stabilized enough, and are meticulously covered with tests, to a point where |
15 | # an effort to formalize them into user-facing APIs might be worthwhile. |
16 | # |
17 | # An implementor working on publicizing and/or replacing the routines with a |
18 | # more modern SQL generation framework should keep in mind that pretty much all |
19 | # existing tests are constructed on the basis of real-world code used in |
20 | # production somewhere. |
21 | # |
22 | # Please hack on this responsibly ;) |
d28bb90d |
23 | # |
24 | |
25 | use strict; |
26 | use warnings; |
27 | |
28 | use base 'DBIx::Class::Storage'; |
29 | use mro 'c3'; |
30 | |
6298a324 |
31 | use Scalar::Util 'blessed'; |
8fc4291e |
32 | use DBIx::Class::_Util qw(UNRESOLVABLE_CONDITION serialize dump_value); |
b5ce6748 |
33 | use SQL::Abstract qw(is_plain_value is_literal_value); |
e466c62b |
34 | use DBIx::Class::Carp; |
6298a324 |
35 | use namespace::clean; |
d28bb90d |
36 | |
37 | # |
052e8431 |
38 | # This code will remove non-selecting/non-restricting joins from |
4b1b5ea3 |
39 | # {from} specs, aiding the RDBMS query optimizer |
052e8431 |
40 | # |
41 | sub _prune_unused_joins { |
e1861c2c |
42 | my ($self, $attrs) = @_; |
ea95892e |
43 | |
e1861c2c |
44 | # only standard {from} specs are supported, and we could be disabled in general |
45 | return ($attrs->{from}, {}) unless ( |
46 | ref $attrs->{from} eq 'ARRAY' |
47 | and |
48 | @{$attrs->{from}} > 1 |
49 | and |
50 | ref $attrs->{from}[0] eq 'HASH' |
51 | and |
52 | ref $attrs->{from}[1] eq 'ARRAY' |
53 | and |
54 | $self->_use_join_optimizer |
55 | ); |
052e8431 |
56 | |
757891ed |
57 | my $orig_aliastypes = |
58 | $attrs->{_precalculated_aliastypes} |
59 | || |
60 | $self->_resolve_aliastypes_from_select_args($attrs) |
61 | ; |
4b1b5ea3 |
62 | |
eb58c082 |
63 | my $new_aliastypes = { %$orig_aliastypes }; |
64 | |
65 | # we will be recreating this entirely |
66 | my @reclassify = 'joining'; |
97e130fa |
67 | |
4b1b5ea3 |
68 | # a grouped set will not be affected by amount of rows. Thus any |
eb58c082 |
69 | # purely multiplicator classifications can go |
70 | # (will be reintroduced below if needed by something else) |
71 | push @reclassify, qw(multiplying premultiplied) |
437a9cfa |
72 | if $attrs->{_force_prune_multiplying_joins} or $attrs->{group_by}; |
4b1b5ea3 |
73 | |
eb58c082 |
74 | # nuke what will be recalculated |
75 | delete @{$new_aliastypes}{@reclassify}; |
76 | |
e1861c2c |
77 | my @newfrom = $attrs->{from}[0]; # FROM head is always present |
052e8431 |
78 | |
eb58c082 |
79 | # recalculate what we need once the multipliers are potentially gone |
80 | # ignore premultiplies, since they do not add any value to anything |
a4812caa |
81 | my %need_joins; |
eb58c082 |
82 | for ( @{$new_aliastypes}{grep { $_ ne 'premultiplied' } keys %$new_aliastypes }) { |
a4812caa |
83 | # add all requested aliases |
84 | $need_joins{$_} = 1 for keys %$_; |
85 | |
86 | # add all their parents (as per joinpath which is an AoH { table => alias }) |
97e130fa |
87 | $need_joins{$_} = 1 for map { values %$_ } map { @{$_->{-parents}} } values %$_; |
a4812caa |
88 | } |
97e130fa |
89 | |
e1861c2c |
90 | for my $j (@{$attrs->{from}}[1..$#{$attrs->{from}}]) { |
539ffe87 |
91 | push @newfrom, $j if ( |
a6ef93cb |
92 | (! defined $j->[0]{-alias}) # legacy crap |
539ffe87 |
93 | || |
94 | $need_joins{$j->[0]{-alias}} |
95 | ); |
052e8431 |
96 | } |
97 | |
eb58c082 |
98 | # we have a new set of joiners - for everything we nuked pull the classification |
99 | # off the original stack |
100 | for my $ctype (@reclassify) { |
101 | $new_aliastypes->{$ctype} = { map |
102 | { $need_joins{$_} ? ( $_ => $orig_aliastypes->{$ctype}{$_} ) : () } |
103 | keys %{$orig_aliastypes->{$ctype}} |
104 | } |
105 | } |
106 | |
107 | return ( \@newfrom, $new_aliastypes ); |
052e8431 |
108 | } |
109 | |
052e8431 |
110 | # |
d28bb90d |
111 | # This is the code producing joined subqueries like: |
8273e845 |
112 | # SELECT me.*, other.* FROM ( SELECT me.* FROM ... ) JOIN other ON ... |
d28bb90d |
113 | # |
114 | sub _adjust_select_args_for_complex_prefetch { |
e1861c2c |
115 | my ($self, $attrs) = @_; |
d28bb90d |
116 | |
e1861c2c |
117 | $self->throw_exception ('Complex prefetches are not supported on resultsets with a custom from attribute') unless ( |
118 | ref $attrs->{from} eq 'ARRAY' |
119 | and |
120 | @{$attrs->{from}} > 1 |
121 | and |
122 | ref $attrs->{from}[0] eq 'HASH' |
123 | and |
124 | ref $attrs->{from}[1] eq 'ARRAY' |
125 | ); |
d28bb90d |
126 | |
1e4f9fb3 |
127 | my $root_alias = $attrs->{alias}; |
128 | |
d28bb90d |
129 | # generate inner/outer attribute lists, remove stuff that doesn't apply |
130 | my $outer_attrs = { %$attrs }; |
e1861c2c |
131 | delete @{$outer_attrs}{qw(from bind rows offset group_by _grouped_by_distinct having)}; |
d28bb90d |
132 | |
6aa93928 |
133 | my $inner_attrs = { %$attrs, _simple_passthrough_construction => 1 }; |
134 | delete @{$inner_attrs}{qw(for collapse select as)}; |
d28bb90d |
135 | |
4df1400e |
136 | # there is no point of ordering the insides if there is no limit |
137 | delete $inner_attrs->{order_by} if ( |
138 | delete $inner_attrs->{_order_is_artificial} |
139 | or |
140 | ! $inner_attrs->{rows} |
141 | ); |
946f6260 |
142 | |
d28bb90d |
143 | # generate the inner/outer select lists |
144 | # for inside we consider only stuff *not* brought in by the prefetch |
145 | # on the outside we substitute any function for its alias |
e1861c2c |
146 | $outer_attrs->{select} = [ @{$attrs->{select}} ]; |
36fd7f07 |
147 | |
97e130fa |
148 | my ($root_node, $root_node_offset); |
27e0370d |
149 | |
e1861c2c |
150 | for my $i (0 .. $#{$inner_attrs->{from}}) { |
151 | my $node = $inner_attrs->{from}[$i]; |
27e0370d |
152 | my $h = (ref $node eq 'HASH') ? $node |
153 | : (ref $node eq 'ARRAY' and ref $node->[0] eq 'HASH') ? $node->[0] |
154 | : next |
155 | ; |
156 | |
1e4f9fb3 |
157 | if ( ($h->{-alias}||'') eq $root_alias and $h->{-rsrc} ) { |
97e130fa |
158 | $root_node = $h; |
159 | $root_node_offset = $i; |
27e0370d |
160 | last; |
161 | } |
162 | } |
163 | |
164 | $self->throw_exception ('Complex prefetches are not supported on resultsets with a custom from attribute') |
97e130fa |
165 | unless $root_node; |
27e0370d |
166 | |
167 | # use the heavy duty resolver to take care of aliased/nonaliased naming |
e1861c2c |
168 | my $colinfo = $self->_resolve_column_info($inner_attrs->{from}); |
27e0370d |
169 | my $selected_root_columns; |
170 | |
e1861c2c |
171 | for my $i (0 .. $#{$outer_attrs->{select}}) { |
172 | my $sel = $outer_attrs->{select}->[$i]; |
d28bb90d |
173 | |
1e4f9fb3 |
174 | next if ( |
175 | $colinfo->{$sel} and $colinfo->{$sel}{-source_alias} ne $root_alias |
176 | ); |
177 | |
d28bb90d |
178 | if (ref $sel eq 'HASH' ) { |
179 | $sel->{-as} ||= $attrs->{as}[$i]; |
e1861c2c |
180 | $outer_attrs->{select}->[$i] = join ('.', $root_alias, ($sel->{-as} || "inner_column_$i") ); |
d28bb90d |
181 | } |
27e0370d |
182 | elsif (! ref $sel and my $ci = $colinfo->{$sel}) { |
183 | $selected_root_columns->{$ci->{-colname}} = 1; |
184 | } |
d28bb90d |
185 | |
e1861c2c |
186 | push @{$inner_attrs->{select}}, $sel; |
bb9bffea |
187 | |
188 | push @{$inner_attrs->{as}}, $attrs->{as}[$i]; |
d28bb90d |
189 | } |
190 | |
757891ed |
191 | my $inner_aliastypes = $self->_resolve_aliastypes_from_select_args($inner_attrs); |
192 | |
193 | # In the inner subq we will need to fetch *only* native columns which may |
97e130fa |
194 | # be a part of an *outer* join condition, or an order_by (which needs to be |
e1861c2c |
195 | # preserved outside), or wheres. In other words everything but the inner |
196 | # selector |
97e130fa |
197 | # We can not just fetch everything because a potential has_many restricting |
198 | # join collapse *will not work* on heavy data types. |
97e130fa |
199 | |
757891ed |
200 | # essentially a map of all non-selecting seen columns |
201 | # the sort is there for a nicer select list |
202 | for ( |
203 | sort |
204 | map |
205 | { keys %{$_->{-seen_columns}||{}} } |
206 | map |
207 | { values %{$inner_aliastypes->{$_}} } |
208 | grep |
209 | { $_ ne 'selecting' } |
210 | keys %$inner_aliastypes |
211 | ) { |
97e130fa |
212 | my $ci = $colinfo->{$_} or next; |
213 | if ( |
1e4f9fb3 |
214 | $ci->{-source_alias} eq $root_alias |
97e130fa |
215 | and |
216 | ! $selected_root_columns->{$ci->{-colname}}++ |
217 | ) { |
218 | # adding it to both to keep limits not supporting dark selectors happy |
e1861c2c |
219 | push @{$inner_attrs->{select}}, $ci->{-fq_colname}; |
97e130fa |
220 | push @{$inner_attrs->{as}}, $ci->{-fq_colname}; |
27e0370d |
221 | } |
222 | } |
223 | |
e1861c2c |
224 | # construct the inner {from} and lock it in a subquery |
48580715 |
225 | # we need to prune first, because this will determine if we need a group_by below |
97e130fa |
226 | # throw away all non-selecting, non-restricting multijoins |
eb58c082 |
227 | # (since we def. do not care about multiplication of the contents of the subquery) |
6395604e |
228 | my $inner_subq = do { |
ea95892e |
229 | |
eb58c082 |
230 | # must use it here regardless of user requests (vastly gentler on optimizer) |
ea95892e |
231 | local $self->{_use_join_optimizer} = 1; |
232 | |
97e130fa |
233 | # throw away multijoins since we def. do not care about those inside the subquery |
757891ed |
234 | # $inner_aliastypes *will* be redefined at this point |
235 | ($inner_attrs->{from}, $inner_aliastypes ) = $self->_prune_unused_joins ({ |
236 | %$inner_attrs, |
237 | _force_prune_multiplying_joins => 1, |
238 | _precalculated_aliastypes => $inner_aliastypes, |
437a9cfa |
239 | }); |
ea95892e |
240 | |
eb58c082 |
241 | # uh-oh a multiplier (which is not us) left in, this is a problem for limits |
242 | # we will need to add a group_by to collapse the resultset for proper counts |
0a3441ee |
243 | if ( |
eb58c082 |
244 | grep { $_ ne $root_alias } keys %{ $inner_aliastypes->{multiplying} || {} } |
1e4f9fb3 |
245 | and |
560978e2 |
246 | # if there are user-supplied groups - assume user knows wtf they are up to |
247 | ( ! $inner_aliastypes->{grouping} or $inner_attrs->{_grouped_by_distinct} ) |
0a3441ee |
248 | ) { |
1e4f9fb3 |
249 | |
eb58c082 |
250 | my $cur_sel = { map { $_ => 1 } @{$inner_attrs->{select}} }; |
1e4f9fb3 |
251 | |
eb58c082 |
252 | # *possibly* supplement the main selection with pks if not already |
253 | # there, as they will have to be a part of the group_by to collapse |
254 | # things properly |
255 | my $inner_select_with_extras; |
256 | my @pks = map { "$root_alias.$_" } $root_node->{-rsrc}->primary_columns |
257 | or $self->throw_exception( sprintf |
258 | 'Unable to perform complex limited prefetch off %s without declared primary key', |
259 | $root_node->{-rsrc}->source_name, |
e1861c2c |
260 | ); |
eb58c082 |
261 | for my $col (@pks) { |
262 | push @{ $inner_select_with_extras ||= [ @{$inner_attrs->{select}} ] }, $col |
263 | unless $cur_sel->{$col}++; |
1e4f9fb3 |
264 | } |
eb58c082 |
265 | |
266 | ($inner_attrs->{group_by}, $inner_attrs->{order_by}) = $self->_group_over_selection({ |
267 | %$inner_attrs, |
268 | $inner_select_with_extras ? ( select => $inner_select_with_extras ) : (), |
269 | _aliastypes => $inner_aliastypes, |
270 | }); |
0a3441ee |
271 | } |
d28bb90d |
272 | |
e1861c2c |
273 | # we already optimized $inner_attrs->{from} above |
97e130fa |
274 | # and already local()ized |
275 | $self->{_use_join_optimizer} = 0; |
d28bb90d |
276 | |
ea95892e |
277 | # generate the subquery |
6395604e |
278 | $self->_select_args_to_query ( |
e1861c2c |
279 | @{$inner_attrs}{qw(from select where)}, |
ea95892e |
280 | $inner_attrs, |
281 | ); |
d28bb90d |
282 | }; |
283 | |
284 | # Generate the outer from - this is relatively easy (really just replace |
285 | # the join slot with the subquery), with a major caveat - we can not |
286 | # join anything that is non-selecting (not part of the prefetch), but at |
287 | # the same time is a multi-type relationship, as it will explode the result. |
288 | # |
289 | # There are two possibilities here |
290 | # - either the join is non-restricting, in which case we simply throw it away |
291 | # - it is part of the restrictions, in which case we need to collapse the outer |
292 | # result by tackling yet another group_by to the outside of the query |
293 | |
27e0370d |
294 | # work on a shallow copy |
e1861c2c |
295 | my @orig_from = @{$attrs->{from}}; |
296 | |
052e8431 |
297 | |
e1861c2c |
298 | $outer_attrs->{from} = \ my @outer_from; |
53c29913 |
299 | |
27e0370d |
300 | # we may not be the head |
97e130fa |
301 | if ($root_node_offset) { |
e1861c2c |
302 | # first generate the outer_from, up to the substitution point |
303 | @outer_from = splice @orig_from, 0, $root_node_offset; |
27e0370d |
304 | |
e1861c2c |
305 | # substitute the subq at the right spot |
27e0370d |
306 | push @outer_from, [ |
307 | { |
1e4f9fb3 |
308 | -alias => $root_alias, |
97e130fa |
309 | -rsrc => $root_node->{-rsrc}, |
1e4f9fb3 |
310 | $root_alias => $inner_subq, |
27e0370d |
311 | }, |
e1861c2c |
312 | # preserve attrs from what is now the head of the from after the splice |
313 | @{$orig_from[0]}[1 .. $#{$orig_from[0]}], |
27e0370d |
314 | ]; |
315 | } |
316 | else { |
27e0370d |
317 | @outer_from = { |
1e4f9fb3 |
318 | -alias => $root_alias, |
27e0370d |
319 | -rsrc => $root_node->{-rsrc}, |
1e4f9fb3 |
320 | $root_alias => $inner_subq, |
27e0370d |
321 | }; |
d28bb90d |
322 | } |
323 | |
e1861c2c |
324 | shift @orig_from; # what we just replaced above |
97e130fa |
325 | |
ea95892e |
326 | # scan the *remaining* from spec against different attributes, and see which joins are needed |
052e8431 |
327 | # in what role |
975b573a |
328 | my $outer_aliastypes = $outer_attrs->{_aliastypes} = |
e1861c2c |
329 | $self->_resolve_aliastypes_from_select_args({ %$outer_attrs, from => \@orig_from }); |
052e8431 |
330 | |
a4812caa |
331 | # unroll parents |
1e4f9fb3 |
332 | my ($outer_select_chain, @outer_nonselecting_chains) = map { +{ |
333 | map { $_ => 1 } map { values %$_} map { @{$_->{-parents}} } values %{ $outer_aliastypes->{$_} || {} } |
334 | } } qw/selecting restricting grouping ordering/; |
a4812caa |
335 | |
d28bb90d |
336 | # see what's left - throw away if not selecting/restricting |
eb58c082 |
337 | my $may_need_outer_group_by; |
e1861c2c |
338 | while (my $j = shift @orig_from) { |
d28bb90d |
339 | my $alias = $j->[0]{-alias}; |
340 | |
a4812caa |
341 | if ( |
342 | $outer_select_chain->{$alias} |
343 | ) { |
344 | push @outer_from, $j |
d28bb90d |
345 | } |
87b12551 |
346 | elsif (grep { $_->{$alias} } @outer_nonselecting_chains ) { |
d28bb90d |
347 | push @outer_from, $j; |
eb58c082 |
348 | $may_need_outer_group_by ||= $outer_aliastypes->{multiplying}{$alias} ? 1 : 0; |
d28bb90d |
349 | } |
350 | } |
351 | |
eb58c082 |
352 | # also throw in a synthetic group_by if a non-selecting multiplier, |
353 | # to guard against cross-join explosions |
354 | # the logic is somewhat fragile, but relies on the idea that if a user supplied |
355 | # a group by on their own - they know what they were doing |
356 | if ( $may_need_outer_group_by and $attrs->{_grouped_by_distinct} ) { |
357 | ($outer_attrs->{group_by}, $outer_attrs->{order_by}) = $self->_group_over_selection ({ |
560978e2 |
358 | %$outer_attrs, |
359 | from => \@outer_from, |
560978e2 |
360 | }); |
36fd7f07 |
361 | } |
362 | |
07fadea8 |
363 | # FIXME: The {where} ends up in both the inner and outer query, i.e. *twice* |
364 | # |
365 | # This is rather horrific, and while we currently *do* have enough |
366 | # introspection tooling available to attempt a stab at properly deciding |
367 | # whether or not to include the where condition on the outside, the |
368 | # machinery is still too slow to apply it here. |
369 | # Thus for the time being we do not attempt any sanitation of the where |
370 | # clause and just pass it through on both sides of the subquery. This *will* |
371 | # be addressed at a later stage, most likely after folding the SQL generator |
372 | # into SQLMaker proper |
d28bb90d |
373 | # |
374 | # OTOH it can be seen as a plus: <ash> (notes that this query would make a DBA cry ;) |
07fadea8 |
375 | # |
e1861c2c |
376 | return $outer_attrs; |
d28bb90d |
377 | } |
378 | |
07fadea8 |
379 | # This is probably the ickiest, yet most relied upon part of the codebase: |
380 | # this is the place where we take arbitrary SQL input and break it into its |
381 | # constituent parts, making sure we know which *sources* are used in what |
382 | # *capacity* ( selecting / restricting / grouping / ordering / joining, etc ) |
383 | # Although the method is pretty horrific, the worst thing that can happen is |
384 | # for a classification failure, which in turn will result in a vocal exception, |
385 | # and will lead to a relatively prompt fix. |
386 | # The code has been slowly improving and is covered with a formiddable battery |
387 | # of tests, so can be considered "reliably stable" at this point (Oct 2015). |
1a736efb |
388 | # |
07fadea8 |
389 | # A note to implementors attempting to "replace" this - keep in mind that while |
390 | # there are multiple optimization avenues, the actual "scan literal elements" |
391 | # part *MAY NEVER BE REMOVED*, even if it is limited only ot the (future) AST |
392 | # nodes that are deemed opaque (i.e. contain literal expressions). The use of |
393 | # blackbox literals is at this point firmly a user-facing API, and is one of |
394 | # *the* reasons DBIC remains as flexible as it is. In other words, when working |
395 | # on this keep in mind that the following is widespread and *encouraged* way |
396 | # of using DBIC in the wild when push comes to shove: |
397 | # |
398 | # $rs->search( {}, { |
399 | # select => \[ $random, @stuff], |
400 | # from => \[ $random, @stuff ], |
401 | # where => \[ $random, @stuff ], |
402 | # group_by => \[ $random, @stuff ], |
403 | # order_by => \[ $random, @stuff ], |
404 | # } ) |
405 | # |
406 | # Various incarnations of the above are reflected in many of the tests. If one |
407 | # gets to fail, you get to fix it. A "this is crazy, nobody does that" is not |
408 | # acceptable going forward. |
1a736efb |
409 | # |
539ffe87 |
410 | sub _resolve_aliastypes_from_select_args { |
e1861c2c |
411 | my ( $self, $attrs ) = @_; |
546f1cd9 |
412 | |
ad630f4b |
413 | $self->throw_exception ('Unable to analyze custom {from}') |
e1861c2c |
414 | if ref $attrs->{from} ne 'ARRAY'; |
546f1cd9 |
415 | |
ad630f4b |
416 | # what we will return |
964a3c71 |
417 | my $aliases_by_type; |
546f1cd9 |
418 | |
ad630f4b |
419 | # see what aliases are there to work with |
eb58c082 |
420 | # and record who is a multiplier and who is premultiplied |
ad630f4b |
421 | my $alias_list; |
e1861c2c |
422 | for my $node (@{$attrs->{from}}) { |
423 | |
424 | my $j = $node; |
ad630f4b |
425 | $j = $j->[0] if ref $j eq 'ARRAY'; |
539ffe87 |
426 | my $al = $j->{-alias} |
427 | or next; |
428 | |
429 | $alias_list->{$al} = $j; |
eb58c082 |
430 | |
431 | $aliases_by_type->{multiplying}{$al} ||= { -parents => $j->{-join_path}||[] } |
a4812caa |
432 | # not array == {from} head == can't be multiplying |
eb58c082 |
433 | if ref($node) eq 'ARRAY' and ! $j->{-is_single}; |
434 | |
435 | $aliases_by_type->{premultiplied}{$al} ||= { -parents => $j->{-join_path}||[] } |
436 | # parts of the path that are not us but are multiplying |
437 | if grep { $aliases_by_type->{multiplying}{$_} } |
438 | grep { $_ ne $al } |
439 | map { values %$_ } |
440 | @{ $j->{-join_path}||[] } |
546f1cd9 |
441 | } |
546f1cd9 |
442 | |
318e3d94 |
443 | # get a column to source/alias map (including unambiguous unqualified ones) |
e1861c2c |
444 | my $colinfo = $self->_resolve_column_info ($attrs->{from}); |
1a736efb |
445 | |
ad630f4b |
446 | # set up a botched SQLA |
447 | my $sql_maker = $self->sql_maker; |
07f31d19 |
448 | |
4c2b30d6 |
449 | # these are throw away results, do not pollute the bind stack |
0542ec57 |
450 | local $sql_maker->{where_bind}; |
451 | local $sql_maker->{group_bind}; |
452 | local $sql_maker->{having_bind}; |
97e130fa |
453 | local $sql_maker->{from_bind}; |
3f5b99fe |
454 | |
455 | # we can't scan properly without any quoting (\b doesn't cut it |
456 | # everywhere), so unless there is proper quoting set - use our |
457 | # own weird impossible character. |
458 | # Also in the case of no quoting, we need to explicitly disable |
459 | # name_sep, otherwise sorry nasty legacy syntax like |
460 | # { 'count(foo.id)' => { '>' => 3 } } will stop working >:( |
461 | local $sql_maker->{quote_char} = $sql_maker->{quote_char}; |
462 | local $sql_maker->{name_sep} = $sql_maker->{name_sep}; |
463 | |
464 | unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) { |
e493ecb2 |
465 | $sql_maker->{quote_char} = ["\x00", "\xFF"]; |
466 | # if we don't unset it we screw up retarded but unfortunately working |
467 | # 'MAX(foo.bar)' => { '>', 3 } |
3f5b99fe |
468 | $sql_maker->{name_sep} = ''; |
469 | } |
470 | |
471 | my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep); |
07f31d19 |
472 | |
1a736efb |
473 | # generate sql chunks |
474 | my $to_scan = { |
475 | restricting => [ |
a9e985b7 |
476 | ($sql_maker->_recurse_where ($attrs->{where}))[0], |
1e4f9fb3 |
477 | $sql_maker->_parse_rs_attrs ({ having => $attrs->{having} }), |
478 | ], |
479 | grouping => [ |
480 | $sql_maker->_parse_rs_attrs ({ group_by => $attrs->{group_by} }), |
1a736efb |
481 | ], |
97e130fa |
482 | joining => [ |
483 | $sql_maker->_recurse_from ( |
e1861c2c |
484 | ref $attrs->{from}[0] eq 'ARRAY' ? $attrs->{from}[0][0] : $attrs->{from}[0], |
485 | @{$attrs->{from}}[1 .. $#{$attrs->{from}}], |
97e130fa |
486 | ), |
487 | ], |
1a736efb |
488 | selecting => [ |
fdd47fe8 |
489 | # kill all selectors which look like a proper subquery |
490 | # this is a sucky heuristic *BUT* - if we get it wrong the query will simply |
491 | # fail to run, so we are relatively safe |
492 | grep |
493 | { $_ !~ / \A \s* \( \s* SELECT \s+ .+? \s+ FROM \s+ .+? \) \s* \z /xsi } |
494 | map |
495 | { ($sql_maker->_recurse_fields($_))[0] } |
496 | @{$attrs->{select}} |
1e4f9fb3 |
497 | ], |
66bbb12c |
498 | ordering => [ map |
499 | { |
500 | ( my $sql = (ref $_ ? $_->[0] : $_) ) =~ s/ \s+ (?: ASC | DESC ) \s* \z //xi; |
501 | $sql; |
502 | } |
503 | $sql_maker->_order_by_chunks( $attrs->{order_by} ), |
1a736efb |
504 | ], |
505 | }; |
07f31d19 |
506 | |
89203568 |
507 | # we will be bulk-scanning anyway - pieces will not matter in that case, |
508 | # thus join everything up |
fdd47fe8 |
509 | # throw away empty-string chunks, and make sure no binds snuck in |
510 | # note that we operate over @{$to_scan->{$type}}, hence the |
511 | # semi-mindbending ... map ... for values ... |
89203568 |
512 | ( $_ = join ' ', map { |
0dadd60d |
513 | |
89203568 |
514 | ( ! defined $_ ) ? () |
8fc4291e |
515 | : ( length ref $_ ) ? $self->throw_exception( |
516 | "Unexpected ref in scan-plan: " . dump_value $_ |
517 | ) |
89203568 |
518 | : ( $_ =~ /^\s*$/ ) ? () |
519 | : $_ |
0dadd60d |
520 | |
89203568 |
521 | } @$_ ) for values %$to_scan; |
fdd47fe8 |
522 | |
523 | # throw away empty to-scan's |
524 | ( |
89203568 |
525 | length $to_scan->{$_} |
fdd47fe8 |
526 | or |
527 | delete $to_scan->{$_} |
528 | ) for keys %$to_scan; |
0dadd60d |
529 | |
07f31d19 |
530 | |
89203568 |
531 | |
90c9dd1d |
532 | # these will be used for matching in the loop below |
533 | my $all_aliases = join ' | ', map { quotemeta $_ } keys %$alias_list; |
534 | my $fq_col_re = qr/ |
535 | $lquote ( $all_aliases ) $rquote $sep (?: $lquote ([^$rquote]+) $rquote )? |
536 | | |
537 | \b ( $all_aliases ) \. ( [^\s\)\($rquote]+ )? |
538 | /x; |
539 | |
89203568 |
540 | |
90c9dd1d |
541 | my $all_unq_columns = join ' | ', |
542 | map |
543 | { quotemeta $_ } |
544 | grep |
545 | # using a regex here shows up on profiles, boggle |
546 | { index( $_, '.') < 0 } |
547 | keys %$colinfo |
548 | ; |
549 | my $unq_col_re = $all_unq_columns |
89203568 |
550 | ? qr/ |
551 | $lquote ( $all_unq_columns ) $rquote |
552 | | |
553 | (?: \A | \s ) ( $all_unq_columns ) (?: \s | \z ) |
554 | /x |
90c9dd1d |
555 | : undef |
556 | ; |
557 | |
558 | |
19955cdf |
559 | # the actual scan, per type |
318e3d94 |
560 | for my $type (keys %$to_scan) { |
19955cdf |
561 | |
90c9dd1d |
562 | |
19955cdf |
563 | # now loop through all fully qualified columns and get the corresponding |
564 | # alias (should work even if they are in scalarrefs) |
90c9dd1d |
565 | # |
89203568 |
566 | # The regex captures in multiples of 4, with one of the two pairs being |
90c9dd1d |
567 | # undef. There may be a *lot* of matches, hence the convoluted loop |
89203568 |
568 | my @matches = $to_scan->{$type} =~ /$fq_col_re/g; |
90c9dd1d |
569 | my $i = 0; |
570 | while( $i < $#matches ) { |
571 | |
572 | if ( |
573 | defined $matches[$i] |
574 | ) { |
575 | $aliases_by_type->{$type}{$matches[$i]} ||= { -parents => $alias_list->{$matches[$i]}{-join_path}||[] }; |
576 | |
577 | $aliases_by_type->{$type}{$matches[$i]}{-seen_columns}{"$matches[$i].$matches[$i+1]"} = "$matches[$i].$matches[$i+1]" |
578 | if defined $matches[$i+1]; |
579 | |
580 | $i += 2; |
1a736efb |
581 | } |
1a736efb |
582 | |
90c9dd1d |
583 | $i += 2; |
584 | } |
1a736efb |
585 | |
07f31d19 |
586 | |
90c9dd1d |
587 | # now loop through unqualified column names, and try to locate them within |
588 | # the chunks, if there are any unqualified columns in the 1st place |
589 | next unless $unq_col_re; |
89203568 |
590 | |
591 | # The regex captures in multiples of 2, one of the two being undef |
592 | for ( $to_scan->{$type} =~ /$unq_col_re/g ) { |
593 | defined $_ or next; |
90c9dd1d |
594 | my $alias = $colinfo->{$_}{-source_alias} or next; |
595 | $aliases_by_type->{$type}{$alias} ||= { -parents => $alias_list->{$alias}{-join_path}||[] }; |
596 | $aliases_by_type->{$type}{$alias}{-seen_columns}{"$alias.$_"} = $_ |
07f31d19 |
597 | } |
598 | } |
599 | |
90c9dd1d |
600 | |
07f31d19 |
601 | # Add any non-left joins to the restriction list (such joins are indeed restrictions) |
19955cdf |
602 | ( |
603 | $_->{-alias} |
604 | and |
605 | ! $aliases_by_type->{restricting}{ $_->{-alias} } |
606 | and |
607 | ( |
608 | not $_->{-join_type} |
07f31d19 |
609 | or |
19955cdf |
610 | $_->{-join_type} !~ /^left (?: \s+ outer)? $/xi |
611 | ) |
612 | and |
613 | $aliases_by_type->{restricting}{ $_->{-alias} } = { -parents => $_->{-join_path}||[] } |
614 | ) for values %$alias_list; |
07f31d19 |
615 | |
90c9dd1d |
616 | |
19955cdf |
617 | # final cleanup |
618 | ( |
619 | keys %{$aliases_by_type->{$_}} |
620 | or |
621 | delete $aliases_by_type->{$_} |
622 | ) for keys %$aliases_by_type; |
1e4f9fb3 |
623 | |
90c9dd1d |
624 | |
19955cdf |
625 | $aliases_by_type; |
07f31d19 |
626 | } |
627 | |
eb58c082 |
628 | # This is the engine behind { distinct => 1 } and the general |
629 | # complex prefetch grouper |
0a3441ee |
630 | sub _group_over_selection { |
560978e2 |
631 | my ($self, $attrs) = @_; |
0a3441ee |
632 | |
560978e2 |
633 | my $colinfos = $self->_resolve_column_info ($attrs->{from}); |
0a3441ee |
634 | |
635 | my (@group_by, %group_index); |
636 | |
36fd7f07 |
637 | # the logic is: if it is a { func => val } we assume an aggregate, |
638 | # otherwise if \'...' or \[...] we assume the user knows what is |
639 | # going on thus group over it |
560978e2 |
640 | for (@{$attrs->{select}}) { |
0a3441ee |
641 | if (! ref($_) or ref ($_) ne 'HASH' ) { |
642 | push @group_by, $_; |
643 | $group_index{$_}++; |
560978e2 |
644 | if ($colinfos->{$_} and $_ !~ /\./ ) { |
0a3441ee |
645 | # add a fully qualified version as well |
560978e2 |
646 | $group_index{"$colinfos->{$_}{-source_alias}.$_"}++; |
0a3441ee |
647 | } |
07f31d19 |
648 | } |
649 | } |
ad630f4b |
650 | |
eb58c082 |
651 | my @order_by = $self->_extract_order_criteria($attrs->{order_by}) |
652 | or return (\@group_by, $attrs->{order_by}); |
653 | |
654 | # add any order_by parts that are not already present in the group_by |
655 | # to maintain SQL cross-compatibility and general sanity |
656 | # |
657 | # also in case the original selection is *not* unique, or in case part |
658 | # of the ORDER BY refers to a multiplier - we will need to replace the |
659 | # skipped order_by elements with their MIN/MAX equivalents as to maintain |
660 | # the proper overall order without polluting the group criteria (and |
661 | # possibly changing the outcome entirely) |
662 | |
663 | my ($leftovers, $sql_maker, @new_order_by, $order_chunks, $aliastypes); |
664 | |
665 | my $group_already_unique = $self->_columns_comprise_identifying_set($colinfos, \@group_by); |
666 | |
667 | for my $o_idx (0 .. $#order_by) { |
668 | |
669 | # if the chunk is already a min/max function - there is nothing left to touch |
670 | next if $order_by[$o_idx][0] =~ /^ (?: min | max ) \s* \( .+ \) $/ix; |
671 | |
0a3441ee |
672 | # only consider real columns (for functions the user got to do an explicit group_by) |
eb58c082 |
673 | my $chunk_ci; |
674 | if ( |
675 | @{$order_by[$o_idx]} != 1 |
676 | or |
677 | # only declare an unknown *plain* identifier as "leftover" if we are called with |
678 | # aliastypes to examine. If there are none - we are still in _resolve_attrs, and |
679 | # can just assume the user knows what they want |
680 | ( ! ( $chunk_ci = $colinfos->{$order_by[$o_idx][0]} ) and $attrs->{_aliastypes} ) |
681 | ) { |
682 | push @$leftovers, $order_by[$o_idx][0]; |
14e26c5f |
683 | } |
560978e2 |
684 | |
eb58c082 |
685 | next unless $chunk_ci; |
686 | |
687 | # no duplication of group criteria |
688 | next if $group_index{$chunk_ci->{-fq_colname}}; |
689 | |
690 | $aliastypes ||= ( |
691 | $attrs->{_aliastypes} |
560978e2 |
692 | or |
eb58c082 |
693 | $self->_resolve_aliastypes_from_select_args({ |
694 | from => $attrs->{from}, |
695 | order_by => $attrs->{order_by}, |
696 | }) |
697 | ) if $group_already_unique; |
698 | |
699 | # check that we are not ordering by a multiplier (if a check is requested at all) |
700 | if ( |
701 | $group_already_unique |
702 | and |
703 | ! $aliastypes->{multiplying}{$chunk_ci->{-source_alias}} |
704 | and |
705 | ! $aliastypes->{premultiplied}{$chunk_ci->{-source_alias}} |
560978e2 |
706 | ) { |
eb58c082 |
707 | push @group_by, $chunk_ci->{-fq_colname}; |
708 | $group_index{$chunk_ci->{-fq_colname}}++ |
560978e2 |
709 | } |
eb58c082 |
710 | else { |
711 | # We need to order by external columns without adding them to the group |
712 | # (eiehter a non-unique selection, or a multi-external) |
713 | # |
714 | # This doesn't really make sense in SQL, however from DBICs point |
715 | # of view is rather valid (e.g. order the leftmost objects by whatever |
716 | # criteria and get the offset/rows many). There is a way around |
717 | # this however in SQL - we simply tae the direction of each piece |
718 | # of the external order and convert them to MIN(X) for ASC or MAX(X) |
719 | # for DESC, and group_by the root columns. The end result should be |
720 | # exactly what we expect |
07fadea8 |
721 | # |
eb58c082 |
722 | $sql_maker ||= $self->sql_maker; |
723 | $order_chunks ||= [ |
724 | map { ref $_ eq 'ARRAY' ? $_ : [ $_ ] } $sql_maker->_order_by_chunks($attrs->{order_by}) |
725 | ]; |
0a3441ee |
726 | |
eb58c082 |
727 | my ($chunk, $is_desc) = $sql_maker->_split_order_chunk($order_chunks->[$o_idx][0]); |
728 | |
07fadea8 |
729 | # we reached that far - wrap any part of the order_by that "responded" |
730 | # to an ordering alias into a MIN/MAX |
eb58c082 |
731 | $new_order_by[$o_idx] = \[ |
732 | sprintf( '%s( %s )%s', |
733 | ($is_desc ? 'MAX' : 'MIN'), |
734 | $chunk, |
735 | ($is_desc ? ' DESC' : ''), |
736 | ), |
737 | @ {$order_chunks->[$o_idx]} [ 1 .. $#{$order_chunks->[$o_idx]} ] |
738 | ]; |
739 | } |
0a3441ee |
740 | } |
741 | |
eb58c082 |
742 | $self->throw_exception ( sprintf |
9736be65 |
743 | 'Unable to programatically derive a required group_by from the supplied ' |
744 | . 'order_by criteria. To proceed either add an explicit group_by, or ' |
745 | . 'simplify your order_by to only include plain columns ' |
746 | . '(supplied order_by: %s)', |
eb58c082 |
747 | join ', ', map { "'$_'" } @$leftovers, |
748 | ) if $leftovers; |
749 | |
750 | # recreate the untouched order parts |
751 | if (@new_order_by) { |
752 | $new_order_by[$_] ||= \ $order_chunks->[$_] for ( 0 .. $#$order_chunks ); |
753 | } |
754 | |
755 | return ( |
756 | \@group_by, |
757 | (@new_order_by ? \@new_order_by : $attrs->{order_by} ), # same ref as original == unchanged |
758 | ); |
07f31d19 |
759 | } |
760 | |
d28bb90d |
761 | sub _resolve_ident_sources { |
762 | my ($self, $ident) = @_; |
763 | |
764 | my $alias2source = {}; |
d28bb90d |
765 | |
766 | # the reason this is so contrived is that $ident may be a {from} |
767 | # structure, specifying multiple tables to join |
6298a324 |
768 | if ( blessed $ident && $ident->isa("DBIx::Class::ResultSource") ) { |
d28bb90d |
769 | # this is compat mode for insert/update/delete which do not deal with aliases |
770 | $alias2source->{me} = $ident; |
d28bb90d |
771 | } |
772 | elsif (ref $ident eq 'ARRAY') { |
773 | |
774 | for (@$ident) { |
775 | my $tabinfo; |
776 | if (ref $_ eq 'HASH') { |
777 | $tabinfo = $_; |
d28bb90d |
778 | } |
779 | if (ref $_ eq 'ARRAY' and ref $_->[0] eq 'HASH') { |
780 | $tabinfo = $_->[0]; |
781 | } |
782 | |
4376a157 |
783 | $alias2source->{$tabinfo->{-alias}} = $tabinfo->{-rsrc} |
784 | if ($tabinfo->{-rsrc}); |
d28bb90d |
785 | } |
786 | } |
787 | |
90f10b5a |
788 | return $alias2source; |
d28bb90d |
789 | } |
790 | |
791 | # Takes $ident, \@column_names |
792 | # |
793 | # returns { $column_name => \%column_info, ... } |
794 | # also note: this adds -result_source => $rsrc to the column info |
795 | # |
09e14fdc |
796 | # If no columns_names are supplied returns info about *all* columns |
797 | # for all sources |
d28bb90d |
798 | sub _resolve_column_info { |
799 | my ($self, $ident, $colnames) = @_; |
8d005ad9 |
800 | |
801 | return {} if $colnames and ! @$colnames; |
802 | |
229401a0 |
803 | my $sources = $self->_resolve_ident_sources($ident); |
804 | |
805 | $_ = { rsrc => $_, colinfos => $_->columns_info } |
806 | for values %$sources; |
d28bb90d |
807 | |
52416317 |
808 | my (%seen_cols, @auto_colnames); |
d28bb90d |
809 | |
810 | # compile a global list of column names, to be able to properly |
811 | # disambiguate unqualified column names (if at all possible) |
229401a0 |
812 | for my $alias (keys %$sources) { |
813 | ( |
814 | ++$seen_cols{$_}{$alias} |
815 | and |
816 | ! $colnames |
817 | and |
818 | push @auto_colnames, "$alias.$_" |
819 | ) for keys %{ $sources->{$alias}{colinfos} }; |
d28bb90d |
820 | } |
821 | |
09e14fdc |
822 | $colnames ||= [ |
823 | @auto_colnames, |
229401a0 |
824 | ( grep { keys %{$seen_cols{$_}} == 1 } keys %seen_cols ), |
09e14fdc |
825 | ]; |
826 | |
229401a0 |
827 | my %return; |
828 | for (@$colnames) { |
829 | my ($colname, $source_alias) = reverse split /\./, $_; |
d28bb90d |
830 | |
229401a0 |
831 | my $assumed_alias = |
832 | $source_alias |
833 | || |
834 | # if the column was seen exactly once - we know which rsrc it came from |
835 | ( |
836 | $seen_cols{$colname} |
837 | and |
838 | keys %{$seen_cols{$colname}} == 1 |
839 | and |
840 | ( %{$seen_cols{$colname}} )[0] |
841 | ) |
842 | || |
843 | next |
844 | ; |
52416317 |
845 | |
229401a0 |
846 | $self->throw_exception( |
847 | "No such column '$colname' on source " . $sources->{$assumed_alias}{rsrc}->source_name |
848 | ) unless $seen_cols{$colname}{$assumed_alias}; |
52416317 |
849 | |
229401a0 |
850 | $return{$_} = { |
851 | %{ $sources->{$assumed_alias}{colinfos}{$colname} }, |
852 | -result_source => $sources->{$assumed_alias}{rsrc}, |
853 | -source_alias => $assumed_alias, |
854 | -fq_colname => "$assumed_alias.$colname", |
81bf295c |
855 | -colname => $colname, |
d28bb90d |
856 | }; |
81bf295c |
857 | |
229401a0 |
858 | $return{"$assumed_alias.$colname"} = $return{$_} |
859 | unless $source_alias; |
d28bb90d |
860 | } |
861 | |
862 | return \%return; |
863 | } |
864 | |
289ac713 |
865 | # The DBIC relationship chaining implementation is pretty simple - every |
866 | # new related_relationship is pushed onto the {from} stack, and the {select} |
867 | # window simply slides further in. This means that when we count somewhere |
868 | # in the middle, we got to make sure that everything in the join chain is an |
869 | # actual inner join, otherwise the count will come back with unpredictable |
870 | # results (a resultset may be generated with _some_ rows regardless of if |
871 | # the relation which the $rs currently selects has rows or not). E.g. |
872 | # $artist_rs->cds->count - normally generates: |
873 | # SELECT COUNT( * ) FROM artist me LEFT JOIN cd cds ON cds.artist = me.artistid |
874 | # which actually returns the number of artists * (number of cds || 1) |
875 | # |
876 | # So what we do here is crawl {from}, determine if the current alias is at |
877 | # the top of the stack, and if not - make sure the chain is inner-joined down |
878 | # to the root. |
879 | # |
31a8aaaf |
880 | sub _inner_join_to_node { |
289ac713 |
881 | my ($self, $from, $alias) = @_; |
882 | |
302d35f8 |
883 | my $switch_branch = $self->_find_join_path_to_node($from, $alias); |
289ac713 |
884 | |
302d35f8 |
885 | return $from unless @{$switch_branch||[]}; |
289ac713 |
886 | |
887 | # So it looks like we will have to switch some stuff around. |
888 | # local() is useless here as we will be leaving the scope |
889 | # anyway, and deep cloning is just too fucking expensive |
8273e845 |
890 | # So replace the first hashref in the node arrayref manually |
289ac713 |
891 | my @new_from = ($from->[0]); |
faeb2407 |
892 | my $sw_idx = { map { (values %$_), 1 } @$switch_branch }; #there's one k/v per join-path |
289ac713 |
893 | |
894 | for my $j (@{$from}[1 .. $#$from]) { |
895 | my $jalias = $j->[0]{-alias}; |
896 | |
897 | if ($sw_idx->{$jalias}) { |
898 | my %attrs = %{$j->[0]}; |
899 | delete $attrs{-join_type}; |
900 | push @new_from, [ |
901 | \%attrs, |
902 | @{$j}[ 1 .. $#$j ], |
903 | ]; |
904 | } |
905 | else { |
906 | push @new_from, $j; |
907 | } |
908 | } |
909 | |
910 | return \@new_from; |
911 | } |
912 | |
302d35f8 |
913 | sub _find_join_path_to_node { |
914 | my ($self, $from, $target_alias) = @_; |
915 | |
916 | # subqueries and other oddness are naturally not supported |
917 | return undef if ( |
918 | ref $from ne 'ARRAY' |
919 | || |
920 | ref $from->[0] ne 'HASH' |
921 | || |
922 | ! defined $from->[0]{-alias} |
923 | ); |
924 | |
925 | # no path - the head is the alias |
926 | return [] if $from->[0]{-alias} eq $target_alias; |
927 | |
928 | for my $i (1 .. $#$from) { |
929 | return $from->[$i][0]{-join_path} if ( ($from->[$i][0]{-alias}||'') eq $target_alias ); |
930 | } |
931 | |
932 | # something else went quite wrong |
933 | return undef; |
934 | } |
935 | |
bac358c9 |
936 | sub _extract_order_criteria { |
1a736efb |
937 | my ($self, $order_by, $sql_maker) = @_; |
c0748280 |
938 | |
1a736efb |
939 | my $parser = sub { |
e6977bbb |
940 | my ($sql_maker, $order_by, $orig_quote_chars) = @_; |
c0748280 |
941 | |
1a736efb |
942 | return scalar $sql_maker->_order_by_chunks ($order_by) |
943 | unless wantarray; |
c0748280 |
944 | |
e6977bbb |
945 | my ($lq, $rq, $sep) = map { quotemeta($_) } ( |
946 | ($orig_quote_chars ? @$orig_quote_chars : $sql_maker->_quote_chars), |
947 | $sql_maker->name_sep |
948 | ); |
949 | |
1a736efb |
950 | my @chunks; |
bac358c9 |
951 | for ($sql_maker->_order_by_chunks ($order_by) ) { |
e6977bbb |
952 | my $chunk = ref $_ ? [ @$_ ] : [ $_ ]; |
cb3e87f5 |
953 | ($chunk->[0]) = $sql_maker->_split_order_chunk($chunk->[0]); |
e6977bbb |
954 | |
955 | # order criteria may have come back pre-quoted (literals and whatnot) |
956 | # this is fragile, but the best we can currently do |
957 | $chunk->[0] =~ s/^ $lq (.+?) $rq $sep $lq (.+?) $rq $/"$1.$2"/xe |
958 | or $chunk->[0] =~ s/^ $lq (.+) $rq $/$1/x; |
959 | |
1a736efb |
960 | push @chunks, $chunk; |
bac6c4fb |
961 | } |
1a736efb |
962 | |
963 | return @chunks; |
964 | }; |
965 | |
966 | if ($sql_maker) { |
967 | return $parser->($sql_maker, $order_by); |
bac6c4fb |
968 | } |
969 | else { |
1a736efb |
970 | $sql_maker = $self->sql_maker; |
e6977bbb |
971 | |
972 | # pass these in to deal with literals coming from |
973 | # the user or the deep guts of prefetch |
974 | my $orig_quote_chars = [$sql_maker->_quote_chars]; |
975 | |
1a736efb |
976 | local $sql_maker->{quote_char}; |
e6977bbb |
977 | return $parser->($sql_maker, $order_by, $orig_quote_chars); |
bac6c4fb |
978 | } |
bac6c4fb |
979 | } |
980 | |
7cec4356 |
981 | sub _order_by_is_stable { |
5f11e54f |
982 | my ($self, $ident, $order_by, $where) = @_; |
c0748280 |
983 | |
eb58c082 |
984 | my @cols = ( |
8d005ad9 |
985 | ( map { $_->[0] } $self->_extract_order_criteria($order_by) ), |
8e40a627 |
986 | ( $where ? keys %{ $self->_extract_fixed_condition_columns($where) } : () ), |
df4312bc |
987 | ) or return 0; |
eb58c082 |
988 | |
989 | my $colinfo = $self->_resolve_column_info($ident, \@cols); |
990 | |
991 | return keys %$colinfo |
992 | ? $self->_columns_comprise_identifying_set( $colinfo, \@cols ) |
df4312bc |
993 | : 0 |
eb58c082 |
994 | ; |
995 | } |
c0748280 |
996 | |
eb58c082 |
997 | sub _columns_comprise_identifying_set { |
998 | my ($self, $colinfo, $columns) = @_; |
7cec4356 |
999 | |
1000 | my $cols_per_src; |
eb58c082 |
1001 | $cols_per_src -> {$_->{-source_alias}} -> {$_->{-colname}} = $_ |
1002 | for grep { defined $_ } @{$colinfo}{@$columns}; |
7cec4356 |
1003 | |
1004 | for (values %$cols_per_src) { |
1005 | my $src = (values %$_)[0]->{-result_source}; |
1006 | return 1 if $src->_identifying_column_set($_); |
c0748280 |
1007 | } |
1008 | |
df4312bc |
1009 | return 0; |
7cec4356 |
1010 | } |
1011 | |
df4312bc |
1012 | # this is almost similar to _order_by_is_stable, except it takes |
0e81e691 |
1013 | # a single rsrc, and will succeed only if the first portion of the order |
1014 | # by is stable. |
1015 | # returns that portion as a colinfo hashref on success |
df4312bc |
1016 | sub _extract_colinfo_of_stable_main_source_order_by_portion { |
302d35f8 |
1017 | my ($self, $attrs) = @_; |
0e81e691 |
1018 | |
302d35f8 |
1019 | my $nodes = $self->_find_join_path_to_node($attrs->{from}, $attrs->{alias}); |
1020 | |
1021 | return unless defined $nodes; |
0e81e691 |
1022 | |
1023 | my @ord_cols = map |
1024 | { $_->[0] } |
302d35f8 |
1025 | ( $self->_extract_order_criteria($attrs->{order_by}) ) |
0e81e691 |
1026 | ; |
1027 | return unless @ord_cols; |
1028 | |
302d35f8 |
1029 | my $valid_aliases = { map { $_ => 1 } ( |
1030 | $attrs->{from}[0]{-alias}, |
1031 | map { values %$_ } @$nodes, |
1032 | ) }; |
318e3d94 |
1033 | |
302d35f8 |
1034 | my $colinfos = $self->_resolve_column_info($attrs->{from}); |
1035 | |
1036 | my ($colinfos_to_return, $seen_main_src_cols); |
1037 | |
1038 | for my $col (@ord_cols) { |
1039 | # if order criteria is unresolvable - there is nothing we can do |
1040 | my $colinfo = $colinfos->{$col} or last; |
1041 | |
1042 | # if we reached the end of the allowed aliases - also nothing we can do |
1043 | last unless $valid_aliases->{$colinfo->{-source_alias}}; |
1044 | |
1045 | $colinfos_to_return->{$col} = $colinfo; |
1046 | |
1047 | $seen_main_src_cols->{$colinfo->{-colname}} = 1 |
1048 | if $colinfo->{-source_alias} eq $attrs->{alias}; |
0e81e691 |
1049 | } |
1050 | |
302d35f8 |
1051 | # FIXME the condition may be singling out things on its own, so we |
1052 | # conceivable could come back wi "stable-ordered by nothing" |
1053 | # not confient enough in the parser yet, so punt for the time being |
1054 | return unless $seen_main_src_cols; |
0e81e691 |
1055 | |
302d35f8 |
1056 | my $main_src_fixed_cols_from_cond = [ $attrs->{where} |
1057 | ? ( |
1058 | map |
1059 | { |
1060 | ( $colinfos->{$_} and $colinfos->{$_}{-source_alias} eq $attrs->{alias} ) |
1061 | ? $colinfos->{$_}{-colname} |
1062 | : () |
1063 | } |
8e40a627 |
1064 | keys %{ $self->_extract_fixed_condition_columns($attrs->{where}) } |
302d35f8 |
1065 | ) |
1066 | : () |
1067 | ]; |
0e81e691 |
1068 | |
302d35f8 |
1069 | return $attrs->{result_source}->_identifying_column_set([ |
1070 | keys %$seen_main_src_cols, |
1071 | @$main_src_fixed_cols_from_cond, |
1072 | ]) ? $colinfos_to_return : (); |
0e81e691 |
1073 | } |
1074 | |
8d005ad9 |
1075 | # Attempts to flatten a passed in SQLA condition as much as possible towards |
1076 | # a plain hashref, *without* altering its semantics. Required by |
1077 | # create/populate being able to extract definitive conditions from preexisting |
1078 | # resultset {where} stacks |
1079 | # |
1080 | # FIXME - while relatively robust, this is still imperfect, one of the first |
07fadea8 |
1081 | # things to tackle when we get access to a formalized AST. Note that this code |
1082 | # is covered by a *ridiculous* amount of tests, so starting with porting this |
1083 | # code would be a rather good exercise |
8d005ad9 |
1084 | sub _collapse_cond { |
1085 | my ($self, $where, $where_is_anded_array) = @_; |
1086 | |
135ac69d |
1087 | my $fin; |
1088 | |
8d005ad9 |
1089 | if (! $where) { |
1090 | return; |
1091 | } |
1092 | elsif ($where_is_anded_array or ref $where eq 'HASH') { |
1093 | |
1094 | my @pairs; |
1095 | |
1096 | my @pieces = $where_is_anded_array ? @$where : $where; |
1097 | while (@pieces) { |
1098 | my $chunk = shift @pieces; |
1099 | |
1100 | if (ref $chunk eq 'HASH') { |
e466c62b |
1101 | for (sort keys %$chunk) { |
1102 | |
1103 | # Match SQLA 1.79 behavior |
d52c4a75 |
1104 | unless( length $_ ) { |
e466c62b |
1105 | is_literal_value($chunk->{$_}) |
1106 | ? carp 'Hash-pairs consisting of an empty string with a literal are deprecated, use -and => [ $literal ] instead' |
1107 | : $self->throw_exception("Supplying an empty left hand side argument is not supported in hash-pairs") |
1108 | ; |
1109 | } |
1110 | |
1111 | push @pairs, $_ => $chunk->{$_}; |
1112 | } |
8d005ad9 |
1113 | } |
1114 | elsif (ref $chunk eq 'ARRAY') { |
6565d2c3 |
1115 | push @pairs, -or => $chunk |
8d005ad9 |
1116 | if @$chunk; |
1117 | } |
b34d9331 |
1118 | elsif ( ! length ref $chunk) { |
e466c62b |
1119 | |
1120 | # Match SQLA 1.79 behavior |
1121 | $self->throw_exception("Supplying an empty left hand side argument is not supported in array-pairs") |
d52c4a75 |
1122 | if $where_is_anded_array and (! defined $chunk or ! length $chunk); |
e466c62b |
1123 | |
6565d2c3 |
1124 | push @pairs, $chunk, shift @pieces; |
8d005ad9 |
1125 | } |
1126 | else { |
6565d2c3 |
1127 | push @pairs, '', $chunk; |
8d005ad9 |
1128 | } |
1129 | } |
1130 | |
1131 | return unless @pairs; |
1132 | |
1133 | my @conds = $self->_collapse_cond_unroll_pairs(\@pairs) |
1134 | or return; |
1135 | |
1136 | # Consolidate various @conds back into something more compact |
8d005ad9 |
1137 | for my $c (@conds) { |
1138 | if (ref $c ne 'HASH') { |
1139 | push @{$fin->{-and}}, $c; |
1140 | } |
1141 | else { |
1142 | for my $col (sort keys %$c) { |
8d005ad9 |
1143 | |
135ac69d |
1144 | # consolidate all -and nodes |
1145 | if ($col =~ /^\-and$/i) { |
1146 | push @{$fin->{-and}}, |
1147 | ref $c->{$col} eq 'ARRAY' ? @{$c->{$col}} |
1148 | : ref $c->{$col} eq 'HASH' ? %{$c->{$col}} |
1149 | : { $col => $c->{$col} } |
1150 | ; |
1151 | } |
1152 | elsif ($col =~ /^\-/) { |
1153 | push @{$fin->{-and}}, { $col => $c->{$col} }; |
1154 | } |
1155 | elsif (exists $fin->{$col}) { |
1156 | $fin->{$col} = [ -and => map { |
1157 | (ref $_ eq 'ARRAY' and ($_->[0]||'') =~ /^\-and$/i ) |
1158 | ? @{$_}[1..$#$_] |
1159 | : $_ |
1160 | ; |
1161 | } ($fin->{$col}, $c->{$col}) ]; |
8d005ad9 |
1162 | } |
1163 | else { |
1164 | $fin->{$col} = $c->{$col}; |
1165 | } |
1166 | } |
1167 | } |
1168 | } |
8d005ad9 |
1169 | } |
1170 | elsif (ref $where eq 'ARRAY') { |
22485a7e |
1171 | # we are always at top-level here, it is safe to dump empty *standalone* pieces |
1172 | my $fin_idx; |
8d005ad9 |
1173 | |
22485a7e |
1174 | for (my $i = 0; $i <= $#$where; $i++ ) { |
8d005ad9 |
1175 | |
e466c62b |
1176 | # Match SQLA 1.79 behavior |
1177 | $self->throw_exception( |
1178 | "Supplying an empty left hand side argument is not supported in array-pairs" |
1179 | ) if (! defined $where->[$i] or ! length $where->[$i]); |
1180 | |
22485a7e |
1181 | my $logic_mod = lc ( ($where->[$i] =~ /^(\-(?:and|or))$/i)[0] || '' ); |
1182 | |
1183 | if ($logic_mod) { |
1184 | $i++; |
1185 | $self->throw_exception("Unsupported top-level op/arg pair: [ $logic_mod => $where->[$i] ]") |
1186 | unless ref $where->[$i] eq 'HASH' or ref $where->[$i] eq 'ARRAY'; |
1187 | |
1188 | my $sub_elt = $self->_collapse_cond({ $logic_mod => $where->[$i] }) |
1189 | or next; |
1190 | |
e466c62b |
1191 | my @keys = keys %$sub_elt; |
1192 | if ( @keys == 1 and $keys[0] !~ /^\-/ ) { |
1193 | $fin_idx->{ "COL_$keys[0]_" . serialize $sub_elt } = $sub_elt; |
1194 | } |
1195 | else { |
1196 | $fin_idx->{ "SER_" . serialize $sub_elt } = $sub_elt; |
1197 | } |
22485a7e |
1198 | } |
1199 | elsif (! length ref $where->[$i] ) { |
135ac69d |
1200 | my $sub_elt = $self->_collapse_cond({ @{$where}[$i, $i+1] }) |
1201 | or next; |
1202 | |
1203 | $fin_idx->{ "COL_$where->[$i]_" . serialize $sub_elt } = $sub_elt; |
22485a7e |
1204 | $i++; |
8d005ad9 |
1205 | } |
1206 | else { |
135ac69d |
1207 | $fin_idx->{ "SER_" . serialize $where->[$i] } = $self->_collapse_cond( $where->[$i] ) || next; |
8d005ad9 |
1208 | } |
1209 | } |
22485a7e |
1210 | |
07add744 |
1211 | if (! $fin_idx) { |
1212 | return; |
1213 | } |
1214 | elsif ( keys %$fin_idx == 1 ) { |
1215 | $fin = (values %$fin_idx)[0]; |
1216 | } |
1217 | else { |
1218 | my @or; |
1219 | |
1220 | # at this point everything is at most one level deep - unroll if needed |
1221 | for (sort keys %$fin_idx) { |
1222 | if ( ref $fin_idx->{$_} eq 'HASH' and keys %{$fin_idx->{$_}} == 1 ) { |
1223 | my ($l, $r) = %{$fin_idx->{$_}}; |
1224 | |
1225 | if ( |
1226 | ref $r eq 'ARRAY' |
1227 | and |
1228 | ( |
1229 | ( @$r == 1 and $l =~ /^\-and$/i ) |
1230 | or |
1231 | $l =~ /^\-or$/i |
1232 | ) |
1233 | ) { |
1234 | push @or, @$r |
1235 | } |
1236 | |
1237 | elsif ( |
1238 | ref $r eq 'HASH' |
1239 | and |
1240 | keys %$r == 1 |
1241 | and |
1242 | $l =~ /^\-(?:and|or)$/i |
1243 | ) { |
1244 | push @or, %$r; |
1245 | } |
1246 | |
1247 | else { |
1248 | push @or, $l, $r; |
1249 | } |
1250 | } |
1251 | else { |
1252 | push @or, $fin_idx->{$_}; |
1253 | } |
1254 | } |
1255 | |
1256 | $fin->{-or} = \@or; |
1257 | } |
8d005ad9 |
1258 | } |
1259 | else { |
1260 | # not a hash not an array |
07add744 |
1261 | $fin = { -and => [ $where ] }; |
135ac69d |
1262 | } |
1263 | |
1264 | # unroll single-element -and's |
1265 | while ( |
1266 | $fin->{-and} |
1267 | and |
1268 | @{$fin->{-and}} < 2 |
1269 | ) { |
1270 | my $and = delete $fin->{-and}; |
1271 | last if @$and == 0; |
1272 | |
1273 | # at this point we have @$and == 1 |
1274 | if ( |
1275 | ref $and->[0] eq 'HASH' |
1276 | and |
1277 | ! grep { exists $fin->{$_} } keys %{$and->[0]} |
1278 | ) { |
1279 | $fin = { |
1280 | %$fin, %{$and->[0]} |
1281 | }; |
1282 | } |
07add744 |
1283 | else { |
1284 | $fin->{-and} = $and; |
1285 | last; |
1286 | } |
135ac69d |
1287 | } |
1288 | |
1289 | # compress same-column conds found in $fin |
1290 | for my $col ( grep { $_ !~ /^\-/ } keys %$fin ) { |
1291 | next unless ref $fin->{$col} eq 'ARRAY' and ($fin->{$col}[0]||'') =~ /^\-and$/i; |
1292 | my $val_bag = { map { |
5379386e |
1293 | (! defined $_ ) ? ( UNDEF => undef ) |
1294 | : ( ! length ref $_ or is_plain_value $_ ) ? ( "VAL_$_" => $_ ) |
135ac69d |
1295 | : ( ( 'SER_' . serialize $_ ) => $_ ) |
1296 | } @{$fin->{$col}}[1 .. $#{$fin->{$col}}] }; |
1297 | |
1298 | if (keys %$val_bag == 1 ) { |
1299 | ($fin->{$col}) = values %$val_bag; |
1300 | } |
1301 | else { |
1302 | $fin->{$col} = [ -and => map { $val_bag->{$_} } sort keys %$val_bag ]; |
1303 | } |
8d005ad9 |
1304 | } |
1305 | |
135ac69d |
1306 | return keys %$fin ? $fin : (); |
8d005ad9 |
1307 | } |
1308 | |
1309 | sub _collapse_cond_unroll_pairs { |
1310 | my ($self, $pairs) = @_; |
1311 | |
1312 | my @conds; |
1313 | |
1314 | while (@$pairs) { |
6565d2c3 |
1315 | my ($lhs, $rhs) = splice @$pairs, 0, 2; |
8d005ad9 |
1316 | |
d52c4a75 |
1317 | if (! length $lhs) { |
8d005ad9 |
1318 | push @conds, $self->_collapse_cond($rhs); |
1319 | } |
1320 | elsif ( $lhs =~ /^\-and$/i ) { |
1321 | push @conds, $self->_collapse_cond($rhs, (ref $rhs eq 'ARRAY')); |
1322 | } |
1323 | elsif ( $lhs =~ /^\-or$/i ) { |
1324 | push @conds, $self->_collapse_cond( |
1325 | (ref $rhs eq 'HASH') ? [ map { $_ => $rhs->{$_} } sort keys %$rhs ] : $rhs |
1326 | ); |
1327 | } |
1328 | else { |
1329 | if (ref $rhs eq 'HASH' and ! keys %$rhs) { |
1330 | # FIXME - SQLA seems to be doing... nothing...? |
1331 | } |
f6fff270 |
1332 | # normalize top level -ident, for saner extract_fixed_condition_columns code |
5f35ba0f |
1333 | elsif (ref $rhs eq 'HASH' and keys %$rhs == 1 and exists $rhs->{-ident}) { |
1334 | push @conds, { $lhs => { '=', $rhs } }; |
1335 | } |
1336 | elsif (ref $rhs eq 'HASH' and keys %$rhs == 1 and exists $rhs->{-value} and is_plain_value $rhs->{-value}) { |
1337 | push @conds, { $lhs => $rhs->{-value} }; |
1338 | } |
8d005ad9 |
1339 | elsif (ref $rhs eq 'HASH' and keys %$rhs == 1 and exists $rhs->{'='}) { |
f6fff270 |
1340 | if ( length ref $rhs->{'='} and is_literal_value $rhs->{'='} ) { |
5f35ba0f |
1341 | push @conds, { $lhs => $rhs }; |
1342 | } |
1343 | else { |
6565d2c3 |
1344 | for my $p ($self->_collapse_cond_unroll_pairs([ $lhs => $rhs->{'='} ])) { |
5f35ba0f |
1345 | |
1346 | # extra sanity check |
1347 | if (keys %$p > 1) { |
5f35ba0f |
1348 | local $Data::Dumper::Deepcopy = 1; |
1349 | $self->throw_exception( |
1350 | "Internal error: unexpected collapse unroll:" |
8fc4291e |
1351 | . dump_value { in => { $lhs => $rhs }, out => $p } |
5f35ba0f |
1352 | ); |
1353 | } |
8d005ad9 |
1354 | |
5f35ba0f |
1355 | my ($l, $r) = %$p; |
8d005ad9 |
1356 | |
f6fff270 |
1357 | push @conds, ( |
1358 | ! length ref $r |
1359 | or |
1360 | # the unroller recursion may return a '=' prepended value already |
1361 | ref $r eq 'HASH' and keys %$rhs == 1 and exists $rhs->{'='} |
1362 | or |
1363 | is_plain_value($r) |
1364 | ) |
5f35ba0f |
1365 | ? { $l => $r } |
1366 | : { $l => { '=' => $r } } |
1367 | ; |
1368 | } |
8d005ad9 |
1369 | } |
1370 | } |
1371 | elsif (ref $rhs eq 'ARRAY') { |
1372 | # some of these conditionals encounter multi-values - roll them out using |
1373 | # an unshift, which will cause extra looping in the while{} above |
1374 | if (! @$rhs ) { |
1375 | push @conds, { $lhs => [] }; |
1376 | } |
1377 | elsif ( ($rhs->[0]||'') =~ /^\-(?:and|or)$/i ) { |
1378 | $self->throw_exception("Value modifier not followed by any values: $lhs => [ $rhs->[0] ] ") |
1379 | if @$rhs == 1; |
1380 | |
1381 | if( $rhs->[0] =~ /^\-and$/i ) { |
6565d2c3 |
1382 | unshift @$pairs, map { $lhs => $_ } @{$rhs}[1..$#$rhs]; |
8d005ad9 |
1383 | } |
1384 | # if not an AND then it's an OR |
1385 | elsif(@$rhs == 2) { |
6565d2c3 |
1386 | unshift @$pairs, $lhs => $rhs->[1]; |
8d005ad9 |
1387 | } |
1388 | else { |
953d5b7d |
1389 | push @conds, { $lhs => [ @{$rhs}[1..$#$rhs] ] }; |
8d005ad9 |
1390 | } |
1391 | } |
1392 | elsif (@$rhs == 1) { |
6565d2c3 |
1393 | unshift @$pairs, $lhs => $rhs->[0]; |
8d005ad9 |
1394 | } |
1395 | else { |
1396 | push @conds, { $lhs => $rhs }; |
1397 | } |
1398 | } |
c1f3f2e8 |
1399 | # unroll func + { -value => ... } |
1400 | elsif ( |
1401 | ref $rhs eq 'HASH' |
1402 | and |
1403 | ( my ($subop) = keys %$rhs ) == 1 |
1404 | and |
1405 | length ref ((values %$rhs)[0]) |
1406 | and |
1407 | my $vref = is_plain_value( (values %$rhs)[0] ) |
1408 | ) { |
5379386e |
1409 | push @conds, { $lhs => { $subop => $$vref } } |
c1f3f2e8 |
1410 | } |
8d005ad9 |
1411 | else { |
1412 | push @conds, { $lhs => $rhs }; |
1413 | } |
1414 | } |
1415 | } |
1416 | |
1417 | return @conds; |
1418 | } |
1419 | |
8e40a627 |
1420 | # Analyzes a given condition and attempts to extract all columns |
1421 | # with a definitive fixed-condition criteria. Returns a hashref |
1422 | # of k/v pairs suitable to be passed to set_columns(), with a |
1423 | # MAJOR CAVEAT - multi-value (contradictory) equalities are still |
1424 | # represented as a reference to the UNRESOVABLE_CONDITION constant |
1425 | # The reason we do this is that some codepaths only care about the |
1426 | # codition being stable, as opposed to actually making sense |
5f11e54f |
1427 | # |
8e40a627 |
1428 | # The normal mode is used to figure out if a resultset is constrained |
1429 | # to a column which is part of a unique constraint, which in turn |
1430 | # allows us to better predict how ordering will behave etc. |
1431 | # |
1432 | # With the optional "consider_nulls" boolean argument, the function |
1433 | # is instead used to infer inambiguous values from conditions |
1434 | # (e.g. the inheritance of resultset conditions on new_result) |
1435 | # |
5f11e54f |
1436 | sub _extract_fixed_condition_columns { |
8e40a627 |
1437 | my ($self, $where, $consider_nulls) = @_; |
1438 | my $where_hash = $self->_collapse_cond($_[1]); |
1439 | |
1440 | my $res = {}; |
1441 | my ($c, $v); |
1442 | for $c (keys %$where_hash) { |
1443 | my $vals; |
1444 | |
1445 | if (!defined ($v = $where_hash->{$c}) ) { |
b34d9331 |
1446 | $vals->{UNDEF} = $v if $consider_nulls |
8e40a627 |
1447 | } |
1448 | elsif ( |
8e40a627 |
1449 | ref $v eq 'HASH' |
1450 | and |
1451 | keys %$v == 1 |
5f35ba0f |
1452 | ) { |
1453 | if (exists $v->{-value}) { |
1454 | if (defined $v->{-value}) { |
b34d9331 |
1455 | $vals->{"VAL_$v->{-value}"} = $v->{-value} |
5f35ba0f |
1456 | } |
1457 | elsif( $consider_nulls ) { |
b34d9331 |
1458 | $vals->{UNDEF} = $v->{-value}; |
5f35ba0f |
1459 | } |
1460 | } |
8e40a627 |
1461 | # do not need to check for plain values - _collapse_cond did it for us |
f6fff270 |
1462 | elsif( |
1463 | length ref $v->{'='} |
1464 | and |
1465 | ( |
1466 | ( ref $v->{'='} eq 'HASH' and keys %{$v->{'='}} == 1 and exists $v->{'='}{-ident} ) |
1467 | or |
1468 | is_literal_value($v->{'='}) |
1469 | ) |
1470 | ) { |
b34d9331 |
1471 | $vals->{ 'SER_' . serialize $v->{'='} } = $v->{'='}; |
5f35ba0f |
1472 | } |
1473 | } |
1474 | elsif ( |
1475 | ! length ref $v |
1476 | or |
1477 | is_plain_value ($v) |
8e40a627 |
1478 | ) { |
b34d9331 |
1479 | $vals->{"VAL_$v"} = $v; |
8e40a627 |
1480 | } |
1481 | elsif (ref $v eq 'ARRAY' and ($v->[0]||'') eq '-and') { |
1482 | for ( @{$v}[1..$#$v] ) { |
1483 | my $subval = $self->_extract_fixed_condition_columns({ $c => $_ }, 'consider nulls'); # always fish nulls out on recursion |
1484 | next unless exists $subval->{$c}; # didn't find anything |
b34d9331 |
1485 | $vals->{ |
1486 | ! defined $subval->{$c} ? 'UNDEF' |
1487 | : ( ! length ref $subval->{$c} or is_plain_value $subval->{$c} ) ? "VAL_$subval->{$c}" |
1488 | : ( 'SER_' . serialize $subval->{$c} ) |
1489 | } = $subval->{$c}; |
8d005ad9 |
1490 | } |
5f11e54f |
1491 | } |
8e40a627 |
1492 | |
1493 | if (keys %$vals == 1) { |
1494 | ($res->{$c}) = (values %$vals) |
b34d9331 |
1495 | unless !$consider_nulls and exists $vals->{UNDEF}; |
8e40a627 |
1496 | } |
1497 | elsif (keys %$vals > 1) { |
1498 | $res->{$c} = UNRESOLVABLE_CONDITION; |
1499 | } |
5f11e54f |
1500 | } |
8d005ad9 |
1501 | |
8e40a627 |
1502 | $res; |
c0748280 |
1503 | } |
bac6c4fb |
1504 | |
d28bb90d |
1505 | 1; |