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 |
6a6394f1 |
7 | # display. The arrival of SQLA2 should immediately obsolete 90% of this |
d28bb90d |
8 | # |
9 | |
10 | use strict; |
11 | use warnings; |
12 | |
13 | use base 'DBIx::Class::Storage'; |
14 | use mro 'c3'; |
15 | |
6298a324 |
16 | use List::Util 'first'; |
17 | use Scalar::Util 'blessed'; |
ea5c7509 |
18 | use Sub::Name 'subname'; |
6298a324 |
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 = $from->[0]; # FROM head is always present |
42 | |
a4812caa |
43 | my %need_joins; |
44 | for (values %$aliastypes) { |
45 | # add all requested aliases |
46 | $need_joins{$_} = 1 for keys %$_; |
47 | |
48 | # add all their parents (as per joinpath which is an AoH { table => alias }) |
49 | $need_joins{$_} = 1 for map { values %$_ } map { @$_ } values %$_; |
50 | } |
052e8431 |
51 | for my $j (@{$from}[1..$#$from]) { |
539ffe87 |
52 | push @newfrom, $j if ( |
4b1b5ea3 |
53 | (! $j->[0]{-alias}) # legacy crap |
539ffe87 |
54 | || |
55 | $need_joins{$j->[0]{-alias}} |
56 | ); |
052e8431 |
57 | } |
58 | |
59 | return \@newfrom; |
60 | } |
61 | |
052e8431 |
62 | # |
d28bb90d |
63 | # This is the code producing joined subqueries like: |
8273e845 |
64 | # SELECT me.*, other.* FROM ( SELECT me.* FROM ... ) JOIN other ON ... |
d28bb90d |
65 | # |
66 | sub _adjust_select_args_for_complex_prefetch { |
67 | my ($self, $from, $select, $where, $attrs) = @_; |
68 | |
69 | $self->throw_exception ('Nothing to prefetch... how did we get here?!') |
36fd7f07 |
70 | if not @{$attrs->{_prefetch_selector_range}}; |
d28bb90d |
71 | |
72 | $self->throw_exception ('Complex prefetches are not supported on resultsets with a custom from attribute') |
73 | if (ref $from ne 'ARRAY' || ref $from->[0] ne 'HASH' || ref $from->[1] ne 'ARRAY'); |
74 | |
75 | |
76 | # generate inner/outer attribute lists, remove stuff that doesn't apply |
77 | my $outer_attrs = { %$attrs }; |
78 | delete $outer_attrs->{$_} for qw/where bind rows offset group_by having/; |
79 | |
86bb5a27 |
80 | my $inner_attrs = { %$attrs, _is_internal_subuery => 1 }; |
908aa1bb |
81 | delete $inner_attrs->{$_} for qw/for collapse _prefetch_selector_range select as/; |
d28bb90d |
82 | |
d28bb90d |
83 | # generate the inner/outer select lists |
84 | # for inside we consider only stuff *not* brought in by the prefetch |
85 | # on the outside we substitute any function for its alias |
86 | my $outer_select = [ @$select ]; |
87 | my $inner_select = []; |
36fd7f07 |
88 | |
89 | my ($p_start, $p_end) = @{$outer_attrs->{_prefetch_selector_range}}; |
90 | for my $i (0 .. $p_start - 1, $p_end + 1 .. $#$outer_select) { |
d28bb90d |
91 | my $sel = $outer_select->[$i]; |
92 | |
93 | if (ref $sel eq 'HASH' ) { |
94 | $sel->{-as} ||= $attrs->{as}[$i]; |
95 | $outer_select->[$i] = join ('.', $attrs->{alias}, ($sel->{-as} || "inner_column_$i") ); |
96 | } |
97 | |
98 | push @$inner_select, $sel; |
bb9bffea |
99 | |
100 | push @{$inner_attrs->{as}}, $attrs->{as}[$i]; |
d28bb90d |
101 | } |
102 | |
ea95892e |
103 | # construct the inner $from and lock it in a subquery |
48580715 |
104 | # we need to prune first, because this will determine if we need a group_by below |
53c29913 |
105 | # the fake group_by is so that the pruner throws away all non-selecting, non-restricting |
106 | # multijoins (since we def. do not care about those inside the subquery) |
ea95892e |
107 | |
6395604e |
108 | my $inner_subq = do { |
ea95892e |
109 | |
110 | # must use it here regardless of user requests |
111 | local $self->{_use_join_optimizer} = 1; |
112 | |
113 | my $inner_from = $self->_prune_unused_joins ($from, $inner_select, $where, { |
114 | group_by => ['dummy'], %$inner_attrs, |
115 | }); |
116 | |
887a0aef |
117 | my $inner_aliastypes = |
118 | $self->_resolve_aliastypes_from_select_args( $inner_from, $inner_select, $where, $inner_attrs ); |
119 | |
a4812caa |
120 | # we need to simulate collapse in the subq if a multiplying join is pulled |
121 | # by being a non-selecting restrictor |
0a3441ee |
122 | if ( |
123 | ! $inner_attrs->{group_by} |
124 | and |
887a0aef |
125 | first { |
126 | $inner_aliastypes->{restricting}{$_} |
127 | and |
128 | ! $inner_aliastypes->{selecting}{$_} |
129 | } ( keys %{$inner_aliastypes->{multiplying}||{}} ) |
0a3441ee |
130 | ) { |
14e26c5f |
131 | my $unprocessed_order_chunks; |
132 | ($inner_attrs->{group_by}, $unprocessed_order_chunks) = $self->_group_over_selection ( |
0a3441ee |
133 | $inner_from, $inner_select, $inner_attrs->{order_by} |
134 | ); |
14e26c5f |
135 | |
136 | $self->throw_exception ( |
137 | 'A required group_by clause could not be constructed automatically due to a complex ' |
138 | . 'order_by criteria. Either order_by columns only (no functions) or construct a suitable ' |
139 | . 'group_by by hand' |
140 | ) if $unprocessed_order_chunks; |
0a3441ee |
141 | } |
d28bb90d |
142 | |
ea95892e |
143 | # we already optimized $inner_from above |
144 | local $self->{_use_join_optimizer} = 0; |
d28bb90d |
145 | |
ea95892e |
146 | # generate the subquery |
6395604e |
147 | $self->_select_args_to_query ( |
ea95892e |
148 | $inner_from, |
149 | $inner_select, |
150 | $where, |
151 | $inner_attrs, |
152 | ); |
d28bb90d |
153 | }; |
154 | |
155 | # Generate the outer from - this is relatively easy (really just replace |
156 | # the join slot with the subquery), with a major caveat - we can not |
157 | # join anything that is non-selecting (not part of the prefetch), but at |
158 | # the same time is a multi-type relationship, as it will explode the result. |
159 | # |
160 | # There are two possibilities here |
161 | # - either the join is non-restricting, in which case we simply throw it away |
162 | # - it is part of the restrictions, in which case we need to collapse the outer |
163 | # result by tackling yet another group_by to the outside of the query |
164 | |
052e8431 |
165 | $from = [ @$from ]; |
052e8431 |
166 | |
d28bb90d |
167 | # so first generate the outer_from, up to the substitution point |
168 | my @outer_from; |
169 | while (my $j = shift @$from) { |
53c29913 |
170 | $j = [ $j ] unless ref $j eq 'ARRAY'; # promote the head-from to an AoH |
171 | |
d28bb90d |
172 | if ($j->[0]{-alias} eq $attrs->{alias}) { # time to swap |
6395604e |
173 | |
d28bb90d |
174 | push @outer_from, [ |
6395604e |
175 | { |
176 | -alias => $attrs->{alias}, |
177 | -rsrc => $j->[0]{-rsrc}, |
178 | $attrs->{alias} => $inner_subq, |
179 | }, |
d28bb90d |
180 | @{$j}[1 .. $#$j], |
181 | ]; |
182 | last; # we'll take care of what's left in $from below |
183 | } |
184 | else { |
185 | push @outer_from, $j; |
186 | } |
187 | } |
188 | |
ea95892e |
189 | # scan the *remaining* from spec against different attributes, and see which joins are needed |
052e8431 |
190 | # in what role |
191 | my $outer_aliastypes = |
539ffe87 |
192 | $self->_resolve_aliastypes_from_select_args( $from, $outer_select, $where, $outer_attrs ); |
052e8431 |
193 | |
a4812caa |
194 | # unroll parents |
195 | my ($outer_select_chain, $outer_restrict_chain) = map { +{ |
196 | map { $_ => 1 } map { values %$_} map { @$_ } values %{ $outer_aliastypes->{$_} || {} } |
197 | } } qw/selecting restricting/; |
198 | |
d28bb90d |
199 | # see what's left - throw away if not selecting/restricting |
a4812caa |
200 | # also throw in a group_by if a non-selecting multiplier, |
201 | # to guard against cross-join explosions |
36fd7f07 |
202 | my $need_outer_group_by; |
d28bb90d |
203 | while (my $j = shift @$from) { |
204 | my $alias = $j->[0]{-alias}; |
205 | |
a4812caa |
206 | if ( |
207 | $outer_select_chain->{$alias} |
208 | ) { |
209 | push @outer_from, $j |
d28bb90d |
210 | } |
a4812caa |
211 | elsif ($outer_restrict_chain->{$alias}) { |
d28bb90d |
212 | push @outer_from, $j; |
a4812caa |
213 | $need_outer_group_by ||= $outer_aliastypes->{multiplying}{$alias} ? 1 : 0; |
d28bb90d |
214 | } |
215 | } |
216 | |
217 | # demote the outer_from head |
218 | $outer_from[0] = $outer_from[0][0]; |
219 | |
36fd7f07 |
220 | if ($need_outer_group_by and ! $outer_attrs->{group_by}) { |
221 | |
222 | my $unprocessed_order_chunks; |
223 | ($outer_attrs->{group_by}, $unprocessed_order_chunks) = $self->_group_over_selection ( |
224 | \@outer_from, $outer_select, $outer_attrs->{order_by} |
225 | ); |
226 | |
227 | $self->throw_exception ( |
228 | 'A required group_by clause could not be constructed automatically due to a complex ' |
229 | . 'order_by criteria. Either order_by columns only (no functions) or construct a suitable ' |
230 | . 'group_by by hand' |
231 | ) if $unprocessed_order_chunks; |
232 | |
233 | } |
234 | |
d28bb90d |
235 | # This is totally horrific - the $where ends up in both the inner and outer query |
236 | # Unfortunately not much can be done until SQLA2 introspection arrives, and even |
237 | # then if where conditions apply to the *right* side of the prefetch, you may have |
238 | # to both filter the inner select (e.g. to apply a limit) and then have to re-filter |
239 | # the outer select to exclude joins you didin't want in the first place |
240 | # |
241 | # OTOH it can be seen as a plus: <ash> (notes that this query would make a DBA cry ;) |
242 | return (\@outer_from, $outer_select, $where, $outer_attrs); |
243 | } |
244 | |
1a736efb |
245 | # |
246 | # I KNOW THIS SUCKS! GET SQLA2 OUT THE DOOR SO THIS CAN DIE! |
247 | # |
ad630f4b |
248 | # Due to a lack of SQLA2 we fall back to crude scans of all the |
249 | # select/where/order/group attributes, in order to determine what |
250 | # aliases are neded to fulfill the query. This information is used |
251 | # throughout the code to prune unnecessary JOINs from the queries |
252 | # in an attempt to reduce the execution time. |
253 | # Although the method is pretty horrific, the worst thing that can |
1a736efb |
254 | # happen is for it to fail due to some scalar SQL, which in turn will |
255 | # result in a vocal exception. |
539ffe87 |
256 | sub _resolve_aliastypes_from_select_args { |
052e8431 |
257 | my ( $self, $from, $select, $where, $attrs ) = @_; |
546f1cd9 |
258 | |
ad630f4b |
259 | $self->throw_exception ('Unable to analyze custom {from}') |
260 | if ref $from ne 'ARRAY'; |
546f1cd9 |
261 | |
ad630f4b |
262 | # what we will return |
964a3c71 |
263 | my $aliases_by_type; |
546f1cd9 |
264 | |
ad630f4b |
265 | # see what aliases are there to work with |
266 | my $alias_list; |
539ffe87 |
267 | for (@$from) { |
268 | my $j = $_; |
ad630f4b |
269 | $j = $j->[0] if ref $j eq 'ARRAY'; |
539ffe87 |
270 | my $al = $j->{-alias} |
271 | or next; |
272 | |
273 | $alias_list->{$al} = $j; |
a4812caa |
274 | $aliases_by_type->{multiplying}{$al} ||= $j->{-join_path}||[] if ( |
275 | # not array == {from} head == can't be multiplying |
276 | ( ref($_) eq 'ARRAY' and ! $j->{-is_single} ) |
277 | or |
278 | # a parent of ours is already a multiplier |
279 | ( grep { $aliases_by_type->{multiplying}{$_} } @{ $j->{-join_path}||[] } ) |
280 | ); |
546f1cd9 |
281 | } |
546f1cd9 |
282 | |
1a736efb |
283 | # get a column to source/alias map (including unqualified ones) |
284 | my $colinfo = $self->_resolve_column_info ($from); |
285 | |
ad630f4b |
286 | # set up a botched SQLA |
287 | my $sql_maker = $self->sql_maker; |
07f31d19 |
288 | |
4c2b30d6 |
289 | # these are throw away results, do not pollute the bind stack |
4c2b30d6 |
290 | local $sql_maker->{select_bind}; |
0542ec57 |
291 | local $sql_maker->{where_bind}; |
292 | local $sql_maker->{group_bind}; |
293 | local $sql_maker->{having_bind}; |
3f5b99fe |
294 | |
295 | # we can't scan properly without any quoting (\b doesn't cut it |
296 | # everywhere), so unless there is proper quoting set - use our |
297 | # own weird impossible character. |
298 | # Also in the case of no quoting, we need to explicitly disable |
299 | # name_sep, otherwise sorry nasty legacy syntax like |
300 | # { 'count(foo.id)' => { '>' => 3 } } will stop working >:( |
301 | local $sql_maker->{quote_char} = $sql_maker->{quote_char}; |
302 | local $sql_maker->{name_sep} = $sql_maker->{name_sep}; |
303 | |
304 | unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) { |
e493ecb2 |
305 | $sql_maker->{quote_char} = ["\x00", "\xFF"]; |
306 | # if we don't unset it we screw up retarded but unfortunately working |
307 | # 'MAX(foo.bar)' => { '>', 3 } |
3f5b99fe |
308 | $sql_maker->{name_sep} = ''; |
309 | } |
310 | |
311 | my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep); |
07f31d19 |
312 | |
1a736efb |
313 | # generate sql chunks |
314 | my $to_scan = { |
315 | restricting => [ |
316 | $sql_maker->_recurse_where ($where), |
a7e643b1 |
317 | $sql_maker->_parse_rs_attrs ({ |
1a736efb |
318 | map { $_ => $attrs->{$_} } (qw/group_by having/) |
319 | }), |
320 | ], |
321 | selecting => [ |
1a736efb |
322 | $sql_maker->_recurse_fields ($select), |
bac358c9 |
323 | ( map { $_->[0] } $self->_extract_order_criteria ($attrs->{order_by}, $sql_maker) ), |
1a736efb |
324 | ], |
325 | }; |
07f31d19 |
326 | |
1a736efb |
327 | # throw away empty chunks |
328 | $_ = [ map { $_ || () } @$_ ] for values %$to_scan; |
07f31d19 |
329 | |
1a736efb |
330 | # first loop through all fully qualified columns and get the corresponding |
331 | # alias (should work even if they are in scalarrefs) |
ad630f4b |
332 | for my $alias (keys %$alias_list) { |
1a736efb |
333 | my $al_re = qr/ |
3f5b99fe |
334 | $lquote $alias $rquote $sep |
1a736efb |
335 | | |
3f5b99fe |
336 | \b $alias \. |
1a736efb |
337 | /x; |
338 | |
1a736efb |
339 | for my $type (keys %$to_scan) { |
340 | for my $piece (@{$to_scan->{$type}}) { |
a4812caa |
341 | $aliases_by_type->{$type}{$alias} ||= $alias_list->{$alias}{-join_path}||[] |
342 | if ($piece =~ $al_re); |
1a736efb |
343 | } |
ad630f4b |
344 | } |
1a736efb |
345 | } |
346 | |
347 | # now loop through unqualified column names, and try to locate them within |
348 | # the chunks |
349 | for my $col (keys %$colinfo) { |
3f5b99fe |
350 | next if $col =~ / \. /x; # if column is qualified it was caught by the above |
1a736efb |
351 | |
3f5b99fe |
352 | my $col_re = qr/ $lquote $col $rquote /x; |
07f31d19 |
353 | |
1a736efb |
354 | for my $type (keys %$to_scan) { |
355 | for my $piece (@{$to_scan->{$type}}) { |
a4812caa |
356 | if ($piece =~ $col_re) { |
357 | my $alias = $colinfo->{$col}{-source_alias}; |
358 | $aliases_by_type->{$type}{$alias} ||= $alias_list->{$alias}{-join_path}||[]; |
359 | } |
1a736efb |
360 | } |
07f31d19 |
361 | } |
362 | } |
363 | |
364 | # Add any non-left joins to the restriction list (such joins are indeed restrictions) |
ad630f4b |
365 | for my $j (values %$alias_list) { |
07f31d19 |
366 | my $alias = $j->{-alias} or next; |
a4812caa |
367 | $aliases_by_type->{restricting}{$alias} ||= $j->{-join_path}||[] if ( |
07f31d19 |
368 | (not $j->{-join_type}) |
369 | or |
370 | ($j->{-join_type} !~ /^left (?: \s+ outer)? $/xi) |
371 | ); |
372 | } |
373 | |
964a3c71 |
374 | return $aliases_by_type; |
07f31d19 |
375 | } |
376 | |
bac358c9 |
377 | # This is the engine behind { distinct => 1 } |
0a3441ee |
378 | sub _group_over_selection { |
379 | my ($self, $from, $select, $order_by) = @_; |
380 | |
381 | my $rs_column_list = $self->_resolve_column_info ($from); |
382 | |
383 | my (@group_by, %group_index); |
384 | |
36fd7f07 |
385 | # the logic is: if it is a { func => val } we assume an aggregate, |
386 | # otherwise if \'...' or \[...] we assume the user knows what is |
387 | # going on thus group over it |
0a3441ee |
388 | for (@$select) { |
389 | if (! ref($_) or ref ($_) ne 'HASH' ) { |
390 | push @group_by, $_; |
391 | $group_index{$_}++; |
392 | if ($rs_column_list->{$_} and $_ !~ /\./ ) { |
393 | # add a fully qualified version as well |
394 | $group_index{"$rs_column_list->{$_}{-source_alias}.$_"}++; |
395 | } |
07f31d19 |
396 | } |
397 | } |
ad630f4b |
398 | |
0a3441ee |
399 | # add any order_by parts that are not already present in the group_by |
400 | # we need to be careful not to add any named functions/aggregates |
bac358c9 |
401 | # i.e. order_by => [ ... { count => 'foo' } ... ] |
14e26c5f |
402 | my @leftovers; |
bac358c9 |
403 | for ($self->_extract_order_criteria($order_by)) { |
0a3441ee |
404 | # only consider real columns (for functions the user got to do an explicit group_by) |
14e26c5f |
405 | if (@$_ != 1) { |
406 | push @leftovers, $_; |
407 | next; |
408 | } |
bac358c9 |
409 | my $chunk = $_->[0]; |
14e26c5f |
410 | my $colinfo = $rs_column_list->{$chunk} or do { |
411 | push @leftovers, $_; |
412 | next; |
413 | }; |
0a3441ee |
414 | |
415 | $chunk = "$colinfo->{-source_alias}.$chunk" if $chunk !~ /\./; |
416 | push @group_by, $chunk unless $group_index{$chunk}++; |
417 | } |
418 | |
14e26c5f |
419 | return wantarray |
420 | ? (\@group_by, (@leftovers ? \@leftovers : undef) ) |
421 | : \@group_by |
422 | ; |
07f31d19 |
423 | } |
424 | |
d28bb90d |
425 | sub _resolve_ident_sources { |
426 | my ($self, $ident) = @_; |
427 | |
428 | my $alias2source = {}; |
429 | my $rs_alias; |
430 | |
431 | # the reason this is so contrived is that $ident may be a {from} |
432 | # structure, specifying multiple tables to join |
6298a324 |
433 | if ( blessed $ident && $ident->isa("DBIx::Class::ResultSource") ) { |
d28bb90d |
434 | # this is compat mode for insert/update/delete which do not deal with aliases |
435 | $alias2source->{me} = $ident; |
436 | $rs_alias = 'me'; |
437 | } |
438 | elsif (ref $ident eq 'ARRAY') { |
439 | |
440 | for (@$ident) { |
441 | my $tabinfo; |
442 | if (ref $_ eq 'HASH') { |
443 | $tabinfo = $_; |
444 | $rs_alias = $tabinfo->{-alias}; |
445 | } |
446 | if (ref $_ eq 'ARRAY' and ref $_->[0] eq 'HASH') { |
447 | $tabinfo = $_->[0]; |
448 | } |
449 | |
4376a157 |
450 | $alias2source->{$tabinfo->{-alias}} = $tabinfo->{-rsrc} |
451 | if ($tabinfo->{-rsrc}); |
d28bb90d |
452 | } |
453 | } |
454 | |
455 | return ($alias2source, $rs_alias); |
456 | } |
457 | |
458 | # Takes $ident, \@column_names |
459 | # |
460 | # returns { $column_name => \%column_info, ... } |
461 | # also note: this adds -result_source => $rsrc to the column info |
462 | # |
09e14fdc |
463 | # If no columns_names are supplied returns info about *all* columns |
464 | # for all sources |
d28bb90d |
465 | sub _resolve_column_info { |
466 | my ($self, $ident, $colnames) = @_; |
467 | my ($alias2src, $root_alias) = $self->_resolve_ident_sources($ident); |
468 | |
52416317 |
469 | my (%seen_cols, @auto_colnames); |
d28bb90d |
470 | |
471 | # compile a global list of column names, to be able to properly |
472 | # disambiguate unqualified column names (if at all possible) |
473 | for my $alias (keys %$alias2src) { |
474 | my $rsrc = $alias2src->{$alias}; |
475 | for my $colname ($rsrc->columns) { |
476 | push @{$seen_cols{$colname}}, $alias; |
3f5b99fe |
477 | push @auto_colnames, "$alias.$colname" unless $colnames; |
d28bb90d |
478 | } |
479 | } |
480 | |
09e14fdc |
481 | $colnames ||= [ |
482 | @auto_colnames, |
483 | grep { @{$seen_cols{$_}} == 1 } (keys %seen_cols), |
484 | ]; |
485 | |
52416317 |
486 | my (%return, $colinfos); |
d28bb90d |
487 | foreach my $col (@$colnames) { |
52416317 |
488 | my ($source_alias, $colname) = $col =~ m/^ (?: ([^\.]+) \. )? (.+) $/x; |
d28bb90d |
489 | |
52416317 |
490 | # if the column was seen exactly once - we know which rsrc it came from |
491 | $source_alias ||= $seen_cols{$colname}[0] |
492 | if ($seen_cols{$colname} and @{$seen_cols{$colname}} == 1); |
d28bb90d |
493 | |
52416317 |
494 | next unless $source_alias; |
495 | |
496 | my $rsrc = $alias2src->{$source_alias} |
497 | or next; |
498 | |
499 | $return{$col} = { |
6395604e |
500 | %{ |
501 | ( $colinfos->{$source_alias} ||= $rsrc->columns_info )->{$colname} |
502 | || |
503 | $self->throw_exception( |
504 | "No such column '$colname' on source " . $rsrc->source_name |
505 | ); |
506 | }, |
d28bb90d |
507 | -result_source => $rsrc, |
52416317 |
508 | -source_alias => $source_alias, |
81bf295c |
509 | -fq_colname => $col eq $colname ? "$source_alias.$col" : $col, |
510 | -colname => $colname, |
d28bb90d |
511 | }; |
81bf295c |
512 | |
513 | $return{"$source_alias.$colname"} = $return{$col} if $col eq $colname; |
d28bb90d |
514 | } |
515 | |
516 | return \%return; |
517 | } |
518 | |
289ac713 |
519 | # The DBIC relationship chaining implementation is pretty simple - every |
520 | # new related_relationship is pushed onto the {from} stack, and the {select} |
521 | # window simply slides further in. This means that when we count somewhere |
522 | # in the middle, we got to make sure that everything in the join chain is an |
523 | # actual inner join, otherwise the count will come back with unpredictable |
524 | # results (a resultset may be generated with _some_ rows regardless of if |
525 | # the relation which the $rs currently selects has rows or not). E.g. |
526 | # $artist_rs->cds->count - normally generates: |
527 | # SELECT COUNT( * ) FROM artist me LEFT JOIN cd cds ON cds.artist = me.artistid |
528 | # which actually returns the number of artists * (number of cds || 1) |
529 | # |
530 | # So what we do here is crawl {from}, determine if the current alias is at |
531 | # the top of the stack, and if not - make sure the chain is inner-joined down |
532 | # to the root. |
533 | # |
31a8aaaf |
534 | sub _inner_join_to_node { |
289ac713 |
535 | my ($self, $from, $alias) = @_; |
536 | |
537 | # subqueries and other oddness are naturally not supported |
538 | return $from if ( |
539 | ref $from ne 'ARRAY' |
540 | || |
541 | @$from <= 1 |
542 | || |
543 | ref $from->[0] ne 'HASH' |
544 | || |
545 | ! $from->[0]{-alias} |
546 | || |
7eb76996 |
547 | $from->[0]{-alias} eq $alias # this last bit means $alias is the head of $from - nothing to do |
289ac713 |
548 | ); |
549 | |
550 | # find the current $alias in the $from structure |
551 | my $switch_branch; |
552 | JOINSCAN: |
553 | for my $j (@{$from}[1 .. $#$from]) { |
554 | if ($j->[0]{-alias} eq $alias) { |
555 | $switch_branch = $j->[0]{-join_path}; |
556 | last JOINSCAN; |
557 | } |
558 | } |
559 | |
7eb76996 |
560 | # something else went quite wrong |
289ac713 |
561 | return $from unless $switch_branch; |
562 | |
563 | # So it looks like we will have to switch some stuff around. |
564 | # local() is useless here as we will be leaving the scope |
565 | # anyway, and deep cloning is just too fucking expensive |
8273e845 |
566 | # So replace the first hashref in the node arrayref manually |
289ac713 |
567 | my @new_from = ($from->[0]); |
faeb2407 |
568 | my $sw_idx = { map { (values %$_), 1 } @$switch_branch }; #there's one k/v per join-path |
289ac713 |
569 | |
570 | for my $j (@{$from}[1 .. $#$from]) { |
571 | my $jalias = $j->[0]{-alias}; |
572 | |
573 | if ($sw_idx->{$jalias}) { |
574 | my %attrs = %{$j->[0]}; |
575 | delete $attrs{-join_type}; |
576 | push @new_from, [ |
577 | \%attrs, |
578 | @{$j}[ 1 .. $#$j ], |
579 | ]; |
580 | } |
581 | else { |
582 | push @new_from, $j; |
583 | } |
584 | } |
585 | |
586 | return \@new_from; |
587 | } |
588 | |
ea5c7509 |
589 | # yet another atrocity: attempt to extract all columns from a |
590 | # where condition by hooking _quote |
591 | sub _extract_condition_columns { |
592 | my ($self, $cond, $sql_maker) = @_; |
593 | |
594 | return [] unless $cond; |
595 | |
596 | $sql_maker ||= $self->{_sql_ident_capturer} ||= do { |
597 | # FIXME - replace with a Moo trait |
598 | my $orig_sm_class = ref $self->sql_maker; |
599 | my $smic_class = "${orig_sm_class}::_IdentCapture_"; |
600 | |
601 | unless ($smic_class->isa('SQL::Abstract')) { |
602 | |
603 | no strict 'refs'; |
604 | *{"${smic_class}::_quote"} = subname "${smic_class}::_quote" => sub { |
605 | my ($self, $ident) = @_; |
606 | if (ref $ident eq 'SCALAR') { |
607 | $ident = $$ident; |
608 | my $storage_quotes = $self->sql_quote_char || '"'; |
609 | my ($ql, $qr) = map |
610 | { quotemeta $_ } |
611 | (ref $storage_quotes eq 'ARRAY' ? @$storage_quotes : ($storage_quotes) x 2 ) |
612 | ; |
613 | |
614 | while ($ident =~ / |
615 | $ql (\w+) $qr |
616 | | |
617 | ([\w\.]+) |
618 | /xg) { |
619 | $self->{_captured_idents}{$1||$2}++; |
620 | } |
bac6c4fb |
621 | } |
037e8dca |
622 | else { |
ea5c7509 |
623 | $self->{_captured_idents}{$ident}++; |
037e8dca |
624 | } |
ea5c7509 |
625 | return $ident; |
626 | }; |
627 | |
628 | *{"${smic_class}::_get_captured_idents"} = subname "${smic_class}::_get_captures" => sub { |
629 | (delete shift->{_captured_idents}) || {}; |
630 | }; |
631 | |
632 | $self->inject_base ($smic_class, $orig_sm_class); |
633 | |
bac6c4fb |
634 | } |
ea5c7509 |
635 | |
636 | $smic_class->new(); |
637 | }; |
638 | |
639 | $sql_maker->_recurse_where($cond); |
640 | |
641 | return [ sort keys %{$sql_maker->_get_captured_idents} ]; |
642 | } |
643 | |
bac358c9 |
644 | sub _extract_order_criteria { |
1a736efb |
645 | my ($self, $order_by, $sql_maker) = @_; |
c0748280 |
646 | |
1a736efb |
647 | my $parser = sub { |
648 | my ($sql_maker, $order_by) = @_; |
c0748280 |
649 | |
1a736efb |
650 | return scalar $sql_maker->_order_by_chunks ($order_by) |
651 | unless wantarray; |
c0748280 |
652 | |
1a736efb |
653 | my @chunks; |
bac358c9 |
654 | for ($sql_maker->_order_by_chunks ($order_by) ) { |
655 | my $chunk = ref $_ ? $_ : [ $_ ]; |
656 | $chunk->[0] =~ s/\s+ (?: ASC|DESC ) \s* $//ix; |
1a736efb |
657 | push @chunks, $chunk; |
bac6c4fb |
658 | } |
1a736efb |
659 | |
660 | return @chunks; |
661 | }; |
662 | |
663 | if ($sql_maker) { |
664 | return $parser->($sql_maker, $order_by); |
bac6c4fb |
665 | } |
666 | else { |
1a736efb |
667 | $sql_maker = $self->sql_maker; |
668 | local $sql_maker->{quote_char}; |
669 | return $parser->($sql_maker, $order_by); |
bac6c4fb |
670 | } |
bac6c4fb |
671 | } |
672 | |
7cec4356 |
673 | sub _order_by_is_stable { |
5f11e54f |
674 | my ($self, $ident, $order_by, $where) = @_; |
c0748280 |
675 | |
5f11e54f |
676 | my $colinfo = $self->_resolve_column_info($ident, [ |
677 | (map { $_->[0] } $self->_extract_order_criteria($order_by)), |
678 | $where ? @{$self->_extract_fixed_condition_columns($where)} :(), |
679 | ]); |
c0748280 |
680 | |
7cec4356 |
681 | return undef unless keys %$colinfo; |
682 | |
683 | my $cols_per_src; |
684 | $cols_per_src->{$_->{-source_alias}}{$_->{-colname}} = $_ for values %$colinfo; |
685 | |
686 | for (values %$cols_per_src) { |
687 | my $src = (values %$_)[0]->{-result_source}; |
688 | return 1 if $src->_identifying_column_set($_); |
c0748280 |
689 | } |
690 | |
7cec4356 |
691 | return undef; |
692 | } |
693 | |
5f11e54f |
694 | # returns an arrayref of column names which *definitely* have som |
695 | # sort of non-nullable equality requested in the given condition |
696 | # specification. This is used to figure out if a resultset is |
697 | # constrained to a column which is part of a unique constraint, |
698 | # which in turn allows us to better predict how ordering will behave |
699 | # etc. |
700 | # |
701 | # this is a rudimentary, incomplete, and error-prone extractor |
702 | # however this is OK - it is conservative, and if we can not find |
703 | # something that is in fact there - the stack will recover gracefully |
704 | # Also - DQ and the mst it rode in on will save us all RSN!!! |
705 | sub _extract_fixed_condition_columns { |
706 | my ($self, $where, $nested) = @_; |
707 | |
708 | return unless ref $where eq 'HASH'; |
709 | |
710 | my @cols; |
711 | for my $lhs (keys %$where) { |
712 | if ($lhs =~ /^\-and$/i) { |
713 | push @cols, ref $where->{$lhs} eq 'ARRAY' |
714 | ? ( map { $self->_extract_fixed_condition_columns($_, 1) } @{$where->{$lhs}} ) |
715 | : $self->_extract_fixed_condition_columns($where->{$lhs}, 1) |
716 | ; |
717 | } |
718 | elsif ($lhs !~ /^\-/) { |
719 | my $val = $where->{$lhs}; |
720 | |
721 | push @cols, $lhs if (defined $val and ( |
722 | ! ref $val |
723 | or |
724 | (ref $val eq 'HASH' and keys %$val == 1 and defined $val->{'='}) |
725 | )); |
726 | } |
727 | } |
728 | return $nested ? @cols : \@cols; |
c0748280 |
729 | } |
bac6c4fb |
730 | |
d28bb90d |
731 | 1; |