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 | |
6298a324 |
16 | use List::Util 'first'; |
17 | use Scalar::Util 'blessed'; |
18 | use namespace::clean; |
d28bb90d |
19 | |
20 | # |
052e8431 |
21 | # This code will remove non-selecting/non-restricting joins from |
4b1b5ea3 |
22 | # {from} specs, aiding the RDBMS query optimizer |
052e8431 |
23 | # |
24 | sub _prune_unused_joins { |
ea95892e |
25 | my $self = shift; |
4b1b5ea3 |
26 | my ($from, $select, $where, $attrs) = @_; |
052e8431 |
27 | |
ea95892e |
28 | return $from unless $self->_use_join_optimizer; |
29 | |
052e8431 |
30 | if (ref $from ne 'ARRAY' || ref $from->[0] ne 'HASH' || ref $from->[1] ne 'ARRAY') { |
31 | return $from; # only standard {from} specs are supported |
32 | } |
33 | |
4b1b5ea3 |
34 | my $aliastypes = $self->_resolve_aliastypes_from_select_args(@_); |
35 | |
36 | # a grouped set will not be affected by amount of rows. Thus any |
37 | # {multiplying} joins can go |
38 | delete $aliastypes->{multiplying} if $attrs->{group_by}; |
39 | |
052e8431 |
40 | my @newfrom = $from->[0]; # FROM head is always present |
41 | |
42 | my %need_joins = (map { %{$_||{}} } (values %$aliastypes) ); |
43 | for my $j (@{$from}[1..$#$from]) { |
539ffe87 |
44 | push @newfrom, $j if ( |
4b1b5ea3 |
45 | (! $j->[0]{-alias}) # legacy crap |
539ffe87 |
46 | || |
47 | $need_joins{$j->[0]{-alias}} |
48 | ); |
052e8431 |
49 | } |
50 | |
51 | return \@newfrom; |
52 | } |
53 | |
052e8431 |
54 | # |
d28bb90d |
55 | # This is the code producing joined subqueries like: |
56 | # SELECT me.*, other.* FROM ( SELECT me.* FROM ... ) JOIN other ON ... |
57 | # |
58 | sub _adjust_select_args_for_complex_prefetch { |
59 | my ($self, $from, $select, $where, $attrs) = @_; |
60 | |
61 | $self->throw_exception ('Nothing to prefetch... how did we get here?!') |
36fd7f07 |
62 | if not @{$attrs->{_prefetch_selector_range}}; |
d28bb90d |
63 | |
64 | $self->throw_exception ('Complex prefetches are not supported on resultsets with a custom from attribute') |
65 | if (ref $from ne 'ARRAY' || ref $from->[0] ne 'HASH' || ref $from->[1] ne 'ARRAY'); |
66 | |
67 | |
68 | # generate inner/outer attribute lists, remove stuff that doesn't apply |
69 | my $outer_attrs = { %$attrs }; |
70 | delete $outer_attrs->{$_} for qw/where bind rows offset group_by having/; |
71 | |
72 | my $inner_attrs = { %$attrs }; |
36fd7f07 |
73 | delete $inner_attrs->{$_} for qw/for collapse _prefetch_selector_range _collapse_order_by select as/; |
d28bb90d |
74 | |
75 | |
76 | # bring over all non-collapse-induced order_by into the inner query (if any) |
77 | # the outer one will have to keep them all |
78 | delete $inner_attrs->{order_by}; |
79 | if (my $ord_cnt = @{$outer_attrs->{order_by}} - @{$outer_attrs->{_collapse_order_by}} ) { |
80 | $inner_attrs->{order_by} = [ |
81 | @{$outer_attrs->{order_by}}[ 0 .. $ord_cnt - 1] |
82 | ]; |
83 | } |
84 | |
d28bb90d |
85 | # generate the inner/outer select lists |
86 | # for inside we consider only stuff *not* brought in by the prefetch |
87 | # on the outside we substitute any function for its alias |
88 | my $outer_select = [ @$select ]; |
89 | my $inner_select = []; |
36fd7f07 |
90 | |
91 | my ($p_start, $p_end) = @{$outer_attrs->{_prefetch_selector_range}}; |
92 | for my $i (0 .. $p_start - 1, $p_end + 1 .. $#$outer_select) { |
d28bb90d |
93 | my $sel = $outer_select->[$i]; |
94 | |
95 | if (ref $sel eq 'HASH' ) { |
96 | $sel->{-as} ||= $attrs->{as}[$i]; |
97 | $outer_select->[$i] = join ('.', $attrs->{alias}, ($sel->{-as} || "inner_column_$i") ); |
98 | } |
99 | |
100 | push @$inner_select, $sel; |
bb9bffea |
101 | |
102 | push @{$inner_attrs->{as}}, $attrs->{as}[$i]; |
d28bb90d |
103 | } |
104 | |
ea95892e |
105 | # construct the inner $from and lock it in a subquery |
48580715 |
106 | # we need to prune first, because this will determine if we need a group_by below |
53c29913 |
107 | # the fake group_by is so that the pruner throws away all non-selecting, non-restricting |
108 | # multijoins (since we def. do not care about those inside the subquery) |
ea95892e |
109 | |
6395604e |
110 | my $inner_subq = do { |
ea95892e |
111 | |
112 | # must use it here regardless of user requests |
113 | local $self->{_use_join_optimizer} = 1; |
114 | |
115 | my $inner_from = $self->_prune_unused_joins ($from, $inner_select, $where, { |
116 | group_by => ['dummy'], %$inner_attrs, |
117 | }); |
118 | |
887a0aef |
119 | my $inner_aliastypes = |
120 | $self->_resolve_aliastypes_from_select_args( $inner_from, $inner_select, $where, $inner_attrs ); |
121 | |
122 | # if a multi-type non-selecting (only restricting) join was needed in the subquery |
123 | # add a group_by to simulate the collapse in the subq |
0a3441ee |
124 | if ( |
125 | ! $inner_attrs->{group_by} |
126 | and |
887a0aef |
127 | first { |
128 | $inner_aliastypes->{restricting}{$_} |
129 | and |
130 | ! $inner_aliastypes->{selecting}{$_} |
131 | } ( keys %{$inner_aliastypes->{multiplying}||{}} ) |
0a3441ee |
132 | ) { |
14e26c5f |
133 | my $unprocessed_order_chunks; |
134 | ($inner_attrs->{group_by}, $unprocessed_order_chunks) = $self->_group_over_selection ( |
0a3441ee |
135 | $inner_from, $inner_select, $inner_attrs->{order_by} |
136 | ); |
14e26c5f |
137 | |
138 | $self->throw_exception ( |
139 | 'A required group_by clause could not be constructed automatically due to a complex ' |
140 | . 'order_by criteria. Either order_by columns only (no functions) or construct a suitable ' |
141 | . 'group_by by hand' |
142 | ) if $unprocessed_order_chunks; |
0a3441ee |
143 | } |
ea95892e |
144 | |
145 | # we already optimized $inner_from above |
146 | local $self->{_use_join_optimizer} = 0; |
147 | |
148 | # generate the subquery |
6395604e |
149 | $self->_select_args_to_query ( |
ea95892e |
150 | $inner_from, |
151 | $inner_select, |
152 | $where, |
153 | $inner_attrs, |
154 | ); |
d28bb90d |
155 | }; |
156 | |
157 | # Generate the outer from - this is relatively easy (really just replace |
158 | # the join slot with the subquery), with a major caveat - we can not |
159 | # join anything that is non-selecting (not part of the prefetch), but at |
160 | # the same time is a multi-type relationship, as it will explode the result. |
161 | # |
162 | # There are two possibilities here |
163 | # - either the join is non-restricting, in which case we simply throw it away |
164 | # - it is part of the restrictions, in which case we need to collapse the outer |
165 | # result by tackling yet another group_by to the outside of the query |
166 | |
052e8431 |
167 | $from = [ @$from ]; |
052e8431 |
168 | |
d28bb90d |
169 | # so first generate the outer_from, up to the substitution point |
170 | my @outer_from; |
171 | while (my $j = shift @$from) { |
53c29913 |
172 | $j = [ $j ] unless ref $j eq 'ARRAY'; # promote the head-from to an AoH |
173 | |
d28bb90d |
174 | if ($j->[0]{-alias} eq $attrs->{alias}) { # time to swap |
6395604e |
175 | |
d28bb90d |
176 | push @outer_from, [ |
6395604e |
177 | { |
178 | -alias => $attrs->{alias}, |
179 | -rsrc => $j->[0]{-rsrc}, |
180 | $attrs->{alias} => $inner_subq, |
181 | }, |
d28bb90d |
182 | @{$j}[1 .. $#$j], |
183 | ]; |
184 | last; # we'll take care of what's left in $from below |
185 | } |
186 | else { |
187 | push @outer_from, $j; |
188 | } |
189 | } |
190 | |
ea95892e |
191 | # scan the *remaining* from spec against different attributes, and see which joins are needed |
052e8431 |
192 | # in what role |
193 | my $outer_aliastypes = |
539ffe87 |
194 | $self->_resolve_aliastypes_from_select_args( $from, $outer_select, $where, $outer_attrs ); |
052e8431 |
195 | |
d28bb90d |
196 | # see what's left - throw away if not selecting/restricting |
197 | # also throw in a group_by if restricting to guard against |
198 | # cross-join explosions |
199 | # |
36fd7f07 |
200 | my $need_outer_group_by; |
d28bb90d |
201 | while (my $j = shift @$from) { |
202 | my $alias = $j->[0]{-alias}; |
203 | |
1a736efb |
204 | if ($outer_aliastypes->{selecting}{$alias}) { |
d28bb90d |
205 | push @outer_from, $j; |
206 | } |
1a736efb |
207 | elsif ($outer_aliastypes->{restricting}{$alias}) { |
d28bb90d |
208 | push @outer_from, $j; |
36fd7f07 |
209 | $need_outer_group_by ||= ! $j->[0]{-is_single}; |
d28bb90d |
210 | } |
211 | } |
212 | |
213 | # demote the outer_from head |
214 | $outer_from[0] = $outer_from[0][0]; |
215 | |
36fd7f07 |
216 | if ($need_outer_group_by and ! $outer_attrs->{group_by}) { |
217 | |
218 | my $unprocessed_order_chunks; |
219 | ($outer_attrs->{group_by}, $unprocessed_order_chunks) = $self->_group_over_selection ( |
220 | \@outer_from, $outer_select, $outer_attrs->{order_by} |
221 | ); |
222 | |
223 | $self->throw_exception ( |
224 | 'A required group_by clause could not be constructed automatically due to a complex ' |
225 | . 'order_by criteria. Either order_by columns only (no functions) or construct a suitable ' |
226 | . 'group_by by hand' |
227 | ) if $unprocessed_order_chunks; |
228 | |
229 | } |
230 | |
d28bb90d |
231 | # This is totally horrific - the $where ends up in both the inner and outer query |
232 | # Unfortunately not much can be done until SQLA2 introspection arrives, and even |
233 | # then if where conditions apply to the *right* side of the prefetch, you may have |
234 | # to both filter the inner select (e.g. to apply a limit) and then have to re-filter |
235 | # the outer select to exclude joins you didin't want in the first place |
236 | # |
237 | # OTOH it can be seen as a plus: <ash> (notes that this query would make a DBA cry ;) |
238 | return (\@outer_from, $outer_select, $where, $outer_attrs); |
239 | } |
240 | |
1a736efb |
241 | # |
242 | # I KNOW THIS SUCKS! GET SQLA2 OUT THE DOOR SO THIS CAN DIE! |
243 | # |
ad630f4b |
244 | # Due to a lack of SQLA2 we fall back to crude scans of all the |
245 | # select/where/order/group attributes, in order to determine what |
246 | # aliases are neded to fulfill the query. This information is used |
247 | # throughout the code to prune unnecessary JOINs from the queries |
248 | # in an attempt to reduce the execution time. |
249 | # Although the method is pretty horrific, the worst thing that can |
1a736efb |
250 | # happen is for it to fail due to some scalar SQL, which in turn will |
251 | # result in a vocal exception. |
539ffe87 |
252 | sub _resolve_aliastypes_from_select_args { |
052e8431 |
253 | my ( $self, $from, $select, $where, $attrs ) = @_; |
546f1cd9 |
254 | |
ad630f4b |
255 | $self->throw_exception ('Unable to analyze custom {from}') |
256 | if ref $from ne 'ARRAY'; |
546f1cd9 |
257 | |
ad630f4b |
258 | # what we will return |
964a3c71 |
259 | my $aliases_by_type; |
546f1cd9 |
260 | |
ad630f4b |
261 | # see what aliases are there to work with |
262 | my $alias_list; |
539ffe87 |
263 | for (@$from) { |
264 | my $j = $_; |
ad630f4b |
265 | $j = $j->[0] if ref $j eq 'ARRAY'; |
539ffe87 |
266 | my $al = $j->{-alias} |
267 | or next; |
268 | |
269 | $alias_list->{$al} = $j; |
270 | $aliases_by_type->{multiplying}{$al} = 1 |
53c29913 |
271 | if ref($_) eq 'ARRAY' and ! $j->{-is_single}; # not array == {from} head == can't be multiplying |
546f1cd9 |
272 | } |
546f1cd9 |
273 | |
1a736efb |
274 | # get a column to source/alias map (including unqualified ones) |
275 | my $colinfo = $self->_resolve_column_info ($from); |
276 | |
ad630f4b |
277 | # set up a botched SQLA |
278 | my $sql_maker = $self->sql_maker; |
07f31d19 |
279 | |
4c2b30d6 |
280 | # these are throw away results, do not pollute the bind stack |
4c2b30d6 |
281 | local $sql_maker->{select_bind}; |
0542ec57 |
282 | local $sql_maker->{where_bind}; |
283 | local $sql_maker->{group_bind}; |
284 | local $sql_maker->{having_bind}; |
3f5b99fe |
285 | |
286 | # we can't scan properly without any quoting (\b doesn't cut it |
287 | # everywhere), so unless there is proper quoting set - use our |
288 | # own weird impossible character. |
289 | # Also in the case of no quoting, we need to explicitly disable |
290 | # name_sep, otherwise sorry nasty legacy syntax like |
291 | # { 'count(foo.id)' => { '>' => 3 } } will stop working >:( |
292 | local $sql_maker->{quote_char} = $sql_maker->{quote_char}; |
293 | local $sql_maker->{name_sep} = $sql_maker->{name_sep}; |
294 | |
295 | unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) { |
e493ecb2 |
296 | $sql_maker->{quote_char} = ["\x00", "\xFF"]; |
297 | # if we don't unset it we screw up retarded but unfortunately working |
298 | # 'MAX(foo.bar)' => { '>', 3 } |
3f5b99fe |
299 | $sql_maker->{name_sep} = ''; |
300 | } |
301 | |
302 | my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep); |
07f31d19 |
303 | |
1a736efb |
304 | # generate sql chunks |
305 | my $to_scan = { |
306 | restricting => [ |
307 | $sql_maker->_recurse_where ($where), |
a7e643b1 |
308 | $sql_maker->_parse_rs_attrs ({ |
1a736efb |
309 | map { $_ => $attrs->{$_} } (qw/group_by having/) |
310 | }), |
311 | ], |
312 | selecting => [ |
1a736efb |
313 | $sql_maker->_recurse_fields ($select), |
bac358c9 |
314 | ( map { $_->[0] } $self->_extract_order_criteria ($attrs->{order_by}, $sql_maker) ), |
1a736efb |
315 | ], |
316 | }; |
317 | |
318 | # throw away empty chunks |
319 | $_ = [ map { $_ || () } @$_ ] for values %$to_scan; |
320 | |
321 | # first loop through all fully qualified columns and get the corresponding |
322 | # alias (should work even if they are in scalarrefs) |
ad630f4b |
323 | for my $alias (keys %$alias_list) { |
1a736efb |
324 | my $al_re = qr/ |
3f5b99fe |
325 | $lquote $alias $rquote $sep |
1a736efb |
326 | | |
3f5b99fe |
327 | \b $alias \. |
1a736efb |
328 | /x; |
329 | |
1a736efb |
330 | for my $type (keys %$to_scan) { |
331 | for my $piece (@{$to_scan->{$type}}) { |
332 | $aliases_by_type->{$type}{$alias} = 1 if ($piece =~ $al_re); |
333 | } |
ad630f4b |
334 | } |
1a736efb |
335 | } |
336 | |
337 | # now loop through unqualified column names, and try to locate them within |
338 | # the chunks |
339 | for my $col (keys %$colinfo) { |
3f5b99fe |
340 | next if $col =~ / \. /x; # if column is qualified it was caught by the above |
1a736efb |
341 | |
3f5b99fe |
342 | my $col_re = qr/ $lquote $col $rquote /x; |
1a736efb |
343 | |
344 | for my $type (keys %$to_scan) { |
345 | for my $piece (@{$to_scan->{$type}}) { |
346 | $aliases_by_type->{$type}{$colinfo->{$col}{-source_alias}} = 1 if ($piece =~ $col_re); |
347 | } |
07f31d19 |
348 | } |
349 | } |
350 | |
351 | # Add any non-left joins to the restriction list (such joins are indeed restrictions) |
ad630f4b |
352 | for my $j (values %$alias_list) { |
07f31d19 |
353 | my $alias = $j->{-alias} or next; |
1a736efb |
354 | $aliases_by_type->{restricting}{$alias} = 1 if ( |
07f31d19 |
355 | (not $j->{-join_type}) |
356 | or |
357 | ($j->{-join_type} !~ /^left (?: \s+ outer)? $/xi) |
358 | ); |
359 | } |
360 | |
ea95892e |
361 | # mark all restricting/selecting join parents as such |
07f31d19 |
362 | # (e.g. join => { cds => 'tracks' } - tracks will need to bring cds too ) |
ea95892e |
363 | for my $type (qw/restricting selecting/) { |
364 | for my $alias (keys %{$aliases_by_type->{$type}||{}}) { |
964a3c71 |
365 | $aliases_by_type->{$type}{$_} = 1 |
faeb2407 |
366 | for (map { values %$_ } @{ $alias_list->{$alias}{-join_path} || [] }); |
07f31d19 |
367 | } |
368 | } |
ad630f4b |
369 | |
964a3c71 |
370 | return $aliases_by_type; |
07f31d19 |
371 | } |
372 | |
bac358c9 |
373 | # This is the engine behind { distinct => 1 } |
0a3441ee |
374 | sub _group_over_selection { |
375 | my ($self, $from, $select, $order_by) = @_; |
376 | |
377 | my $rs_column_list = $self->_resolve_column_info ($from); |
378 | |
379 | my (@group_by, %group_index); |
380 | |
36fd7f07 |
381 | # the logic is: if it is a { func => val } we assume an aggregate, |
382 | # otherwise if \'...' or \[...] we assume the user knows what is |
383 | # going on thus group over it |
0a3441ee |
384 | for (@$select) { |
385 | if (! ref($_) or ref ($_) ne 'HASH' ) { |
386 | push @group_by, $_; |
387 | $group_index{$_}++; |
388 | if ($rs_column_list->{$_} and $_ !~ /\./ ) { |
389 | # add a fully qualified version as well |
390 | $group_index{"$rs_column_list->{$_}{-source_alias}.$_"}++; |
391 | } |
392 | } |
393 | } |
394 | |
395 | # add any order_by parts that are not already present in the group_by |
396 | # we need to be careful not to add any named functions/aggregates |
bac358c9 |
397 | # i.e. order_by => [ ... { count => 'foo' } ... ] |
14e26c5f |
398 | my @leftovers; |
bac358c9 |
399 | for ($self->_extract_order_criteria($order_by)) { |
0a3441ee |
400 | # only consider real columns (for functions the user got to do an explicit group_by) |
14e26c5f |
401 | if (@$_ != 1) { |
402 | push @leftovers, $_; |
403 | next; |
404 | } |
bac358c9 |
405 | my $chunk = $_->[0]; |
14e26c5f |
406 | my $colinfo = $rs_column_list->{$chunk} or do { |
407 | push @leftovers, $_; |
408 | next; |
409 | }; |
0a3441ee |
410 | |
411 | $chunk = "$colinfo->{-source_alias}.$chunk" if $chunk !~ /\./; |
412 | push @group_by, $chunk unless $group_index{$chunk}++; |
413 | } |
414 | |
14e26c5f |
415 | return wantarray |
416 | ? (\@group_by, (@leftovers ? \@leftovers : undef) ) |
417 | : \@group_by |
418 | ; |
0a3441ee |
419 | } |
420 | |
d28bb90d |
421 | sub _resolve_ident_sources { |
422 | my ($self, $ident) = @_; |
423 | |
424 | my $alias2source = {}; |
425 | my $rs_alias; |
426 | |
427 | # the reason this is so contrived is that $ident may be a {from} |
428 | # structure, specifying multiple tables to join |
6298a324 |
429 | if ( blessed $ident && $ident->isa("DBIx::Class::ResultSource") ) { |
d28bb90d |
430 | # this is compat mode for insert/update/delete which do not deal with aliases |
431 | $alias2source->{me} = $ident; |
432 | $rs_alias = 'me'; |
433 | } |
434 | elsif (ref $ident eq 'ARRAY') { |
435 | |
436 | for (@$ident) { |
437 | my $tabinfo; |
438 | if (ref $_ eq 'HASH') { |
439 | $tabinfo = $_; |
440 | $rs_alias = $tabinfo->{-alias}; |
441 | } |
442 | if (ref $_ eq 'ARRAY' and ref $_->[0] eq 'HASH') { |
443 | $tabinfo = $_->[0]; |
444 | } |
445 | |
4376a157 |
446 | $alias2source->{$tabinfo->{-alias}} = $tabinfo->{-rsrc} |
447 | if ($tabinfo->{-rsrc}); |
d28bb90d |
448 | } |
449 | } |
450 | |
451 | return ($alias2source, $rs_alias); |
452 | } |
453 | |
454 | # Takes $ident, \@column_names |
455 | # |
456 | # returns { $column_name => \%column_info, ... } |
457 | # also note: this adds -result_source => $rsrc to the column info |
458 | # |
09e14fdc |
459 | # If no columns_names are supplied returns info about *all* columns |
460 | # for all sources |
d28bb90d |
461 | sub _resolve_column_info { |
462 | my ($self, $ident, $colnames) = @_; |
463 | my ($alias2src, $root_alias) = $self->_resolve_ident_sources($ident); |
464 | |
52416317 |
465 | my (%seen_cols, @auto_colnames); |
d28bb90d |
466 | |
467 | # compile a global list of column names, to be able to properly |
468 | # disambiguate unqualified column names (if at all possible) |
469 | for my $alias (keys %$alias2src) { |
470 | my $rsrc = $alias2src->{$alias}; |
471 | for my $colname ($rsrc->columns) { |
472 | push @{$seen_cols{$colname}}, $alias; |
3f5b99fe |
473 | push @auto_colnames, "$alias.$colname" unless $colnames; |
d28bb90d |
474 | } |
475 | } |
476 | |
09e14fdc |
477 | $colnames ||= [ |
478 | @auto_colnames, |
479 | grep { @{$seen_cols{$_}} == 1 } (keys %seen_cols), |
480 | ]; |
481 | |
52416317 |
482 | my (%return, $colinfos); |
d28bb90d |
483 | foreach my $col (@$colnames) { |
52416317 |
484 | my ($source_alias, $colname) = $col =~ m/^ (?: ([^\.]+) \. )? (.+) $/x; |
d28bb90d |
485 | |
52416317 |
486 | # if the column was seen exactly once - we know which rsrc it came from |
487 | $source_alias ||= $seen_cols{$colname}[0] |
488 | if ($seen_cols{$colname} and @{$seen_cols{$colname}} == 1); |
d28bb90d |
489 | |
52416317 |
490 | next unless $source_alias; |
491 | |
492 | my $rsrc = $alias2src->{$source_alias} |
493 | or next; |
494 | |
495 | $return{$col} = { |
6395604e |
496 | %{ |
497 | ( $colinfos->{$source_alias} ||= $rsrc->columns_info )->{$colname} |
498 | || |
499 | $self->throw_exception( |
500 | "No such column '$colname' on source " . $rsrc->source_name |
501 | ); |
502 | }, |
d28bb90d |
503 | -result_source => $rsrc, |
52416317 |
504 | -source_alias => $source_alias, |
d28bb90d |
505 | }; |
506 | } |
507 | |
508 | return \%return; |
509 | } |
510 | |
289ac713 |
511 | # The DBIC relationship chaining implementation is pretty simple - every |
512 | # new related_relationship is pushed onto the {from} stack, and the {select} |
513 | # window simply slides further in. This means that when we count somewhere |
514 | # in the middle, we got to make sure that everything in the join chain is an |
515 | # actual inner join, otherwise the count will come back with unpredictable |
516 | # results (a resultset may be generated with _some_ rows regardless of if |
517 | # the relation which the $rs currently selects has rows or not). E.g. |
518 | # $artist_rs->cds->count - normally generates: |
519 | # SELECT COUNT( * ) FROM artist me LEFT JOIN cd cds ON cds.artist = me.artistid |
520 | # which actually returns the number of artists * (number of cds || 1) |
521 | # |
522 | # So what we do here is crawl {from}, determine if the current alias is at |
523 | # the top of the stack, and if not - make sure the chain is inner-joined down |
524 | # to the root. |
525 | # |
31a8aaaf |
526 | sub _inner_join_to_node { |
289ac713 |
527 | my ($self, $from, $alias) = @_; |
528 | |
529 | # subqueries and other oddness are naturally not supported |
530 | return $from if ( |
531 | ref $from ne 'ARRAY' |
532 | || |
533 | @$from <= 1 |
534 | || |
535 | ref $from->[0] ne 'HASH' |
536 | || |
537 | ! $from->[0]{-alias} |
538 | || |
7eb76996 |
539 | $from->[0]{-alias} eq $alias # this last bit means $alias is the head of $from - nothing to do |
289ac713 |
540 | ); |
541 | |
542 | # find the current $alias in the $from structure |
543 | my $switch_branch; |
544 | JOINSCAN: |
545 | for my $j (@{$from}[1 .. $#$from]) { |
546 | if ($j->[0]{-alias} eq $alias) { |
547 | $switch_branch = $j->[0]{-join_path}; |
548 | last JOINSCAN; |
549 | } |
550 | } |
551 | |
7eb76996 |
552 | # something else went quite wrong |
289ac713 |
553 | return $from unless $switch_branch; |
554 | |
555 | # So it looks like we will have to switch some stuff around. |
556 | # local() is useless here as we will be leaving the scope |
557 | # anyway, and deep cloning is just too fucking expensive |
7eb76996 |
558 | # So replace the first hashref in the node arrayref manually |
289ac713 |
559 | my @new_from = ($from->[0]); |
faeb2407 |
560 | my $sw_idx = { map { (values %$_), 1 } @$switch_branch }; #there's one k/v per join-path |
289ac713 |
561 | |
562 | for my $j (@{$from}[1 .. $#$from]) { |
563 | my $jalias = $j->[0]{-alias}; |
564 | |
565 | if ($sw_idx->{$jalias}) { |
566 | my %attrs = %{$j->[0]}; |
567 | delete $attrs{-join_type}; |
568 | push @new_from, [ |
569 | \%attrs, |
570 | @{$j}[ 1 .. $#$j ], |
571 | ]; |
572 | } |
573 | else { |
574 | push @new_from, $j; |
575 | } |
576 | } |
577 | |
578 | return \@new_from; |
579 | } |
580 | |
bac6c4fb |
581 | # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus |
582 | # a condition containing 'me' or other table prefixes will not work |
583 | # at all. What this code tries to do (badly) is introspect the condition |
584 | # and remove all column qualifiers. If it bails out early (returns undef) |
585 | # the calling code should try another approach (e.g. a subquery) |
61f031bf |
586 | |
587 | sub _strip_cond_qualifiers_from_array { |
588 | my ($self, $where) = @_; |
589 | my @cond; |
590 | for (my $i = 0; $i < @$where; $i++) { |
591 | my $entry = $where->[$i]; |
592 | my $hash; |
593 | my $ref = ref $entry; |
594 | if ($ref eq 'HASH' or $ref eq 'ARRAY') { |
595 | $hash = $self->_strip_cond_qualifiers($entry); |
596 | } |
597 | elsif (! $ref) { |
598 | $entry =~ /([^.]+)$/; |
599 | $hash->{$1} = $where->[++$i]; |
600 | } |
601 | push @cond, $hash; |
602 | } |
603 | return \@cond; |
604 | } |
605 | |
bac6c4fb |
606 | sub _strip_cond_qualifiers { |
607 | my ($self, $where) = @_; |
608 | |
609 | my $cond = {}; |
610 | |
611 | # No-op. No condition, we're updating/deleting everything |
612 | return $cond unless $where; |
613 | |
614 | if (ref $where eq 'ARRAY') { |
61f031bf |
615 | $cond = $self->_strip_cond_qualifiers_from_array($where); |
bac6c4fb |
616 | } |
617 | elsif (ref $where eq 'HASH') { |
618 | if ( (keys %$where) == 1 && ( (keys %{$where})[0] eq '-and' )) { |
61f031bf |
619 | $cond->{-and} = |
620 | $self->_strip_cond_qualifiers_from_array($where->{-and}); |
bac6c4fb |
621 | } |
622 | else { |
623 | foreach my $key (keys %$where) { |
59ac6523 |
624 | if ($key eq '-or' && ref $where->{$key} eq 'ARRAY') { |
625 | $cond->{$key} = $self->_strip_cond_qualifiers($where->{$key}); |
626 | } |
627 | else { |
628 | $key =~ /([^.]+)$/; |
629 | $cond->{$1} = $where->{$key}; |
630 | } |
bac6c4fb |
631 | } |
632 | } |
633 | } |
634 | else { |
635 | return undef; |
636 | } |
637 | |
638 | return $cond; |
639 | } |
640 | |
bac358c9 |
641 | sub _extract_order_criteria { |
1a736efb |
642 | my ($self, $order_by, $sql_maker) = @_; |
c0748280 |
643 | |
1a736efb |
644 | my $parser = sub { |
645 | my ($sql_maker, $order_by) = @_; |
c0748280 |
646 | |
1a736efb |
647 | return scalar $sql_maker->_order_by_chunks ($order_by) |
648 | unless wantarray; |
c0748280 |
649 | |
1a736efb |
650 | my @chunks; |
bac358c9 |
651 | for ($sql_maker->_order_by_chunks ($order_by) ) { |
652 | my $chunk = ref $_ ? $_ : [ $_ ]; |
653 | $chunk->[0] =~ s/\s+ (?: ASC|DESC ) \s* $//ix; |
1a736efb |
654 | push @chunks, $chunk; |
655 | } |
656 | |
657 | return @chunks; |
658 | }; |
659 | |
660 | if ($sql_maker) { |
661 | return $parser->($sql_maker, $order_by); |
662 | } |
663 | else { |
664 | $sql_maker = $self->sql_maker; |
665 | local $sql_maker->{quote_char}; |
666 | return $parser->($sql_maker, $order_by); |
667 | } |
c0748280 |
668 | } |
bac6c4fb |
669 | |
d28bb90d |
670 | 1; |