Commit | Line | Data |
c443438f |
1 | package #hide from PAUSE |
2 | DBIx::Class::Storage::DBIHacks; |
d28bb90d |
3 | |
4 | # |
5 | # This module contains code that should never have seen the light of day, |
6 | # does not belong in the Storage, or is otherwise unfit for public |
7eb76996 |
7 | # display. The arrival of SQLA2 should immediately oboslete 90% of this |
d28bb90d |
8 | # |
9 | |
10 | use strict; |
11 | use warnings; |
12 | |
13 | use base 'DBIx::Class::Storage'; |
14 | use mro 'c3'; |
15 | |
16 | use Carp::Clan qw/^DBIx::Class/; |
6298a324 |
17 | use List::Util 'first'; |
18 | use Scalar::Util 'blessed'; |
19 | use namespace::clean; |
d28bb90d |
20 | |
21 | # |
052e8431 |
22 | # This code will remove non-selecting/non-restricting joins from |
4b1b5ea3 |
23 | # {from} specs, aiding the RDBMS query optimizer |
052e8431 |
24 | # |
25 | sub _prune_unused_joins { |
ea95892e |
26 | my $self = shift; |
4b1b5ea3 |
27 | my ($from, $select, $where, $attrs) = @_; |
052e8431 |
28 | |
ea95892e |
29 | return $from unless $self->_use_join_optimizer; |
30 | |
052e8431 |
31 | if (ref $from ne 'ARRAY' || ref $from->[0] ne 'HASH' || ref $from->[1] ne 'ARRAY') { |
32 | return $from; # only standard {from} specs are supported |
33 | } |
34 | |
4b1b5ea3 |
35 | my $aliastypes = $self->_resolve_aliastypes_from_select_args(@_); |
36 | |
37 | # a grouped set will not be affected by amount of rows. Thus any |
38 | # {multiplying} joins can go |
39 | delete $aliastypes->{multiplying} if $attrs->{group_by}; |
40 | |
052e8431 |
41 | my @newfrom = $from->[0]; # FROM head is always present |
42 | |
43 | my %need_joins = (map { %{$_||{}} } (values %$aliastypes) ); |
44 | for my $j (@{$from}[1..$#$from]) { |
539ffe87 |
45 | push @newfrom, $j if ( |
4b1b5ea3 |
46 | (! $j->[0]{-alias}) # legacy crap |
539ffe87 |
47 | || |
48 | $need_joins{$j->[0]{-alias}} |
49 | ); |
052e8431 |
50 | } |
51 | |
52 | return \@newfrom; |
53 | } |
54 | |
052e8431 |
55 | # |
d28bb90d |
56 | # This is the code producing joined subqueries like: |
57 | # SELECT me.*, other.* FROM ( SELECT me.* FROM ... ) JOIN other ON ... |
58 | # |
59 | sub _adjust_select_args_for_complex_prefetch { |
60 | my ($self, $from, $select, $where, $attrs) = @_; |
61 | |
62 | $self->throw_exception ('Nothing to prefetch... how did we get here?!') |
63 | if not @{$attrs->{_prefetch_select}}; |
64 | |
65 | $self->throw_exception ('Complex prefetches are not supported on resultsets with a custom from attribute') |
66 | if (ref $from ne 'ARRAY' || ref $from->[0] ne 'HASH' || ref $from->[1] ne 'ARRAY'); |
67 | |
68 | |
69 | # generate inner/outer attribute lists, remove stuff that doesn't apply |
70 | my $outer_attrs = { %$attrs }; |
71 | delete $outer_attrs->{$_} for qw/where bind rows offset group_by having/; |
72 | |
73 | my $inner_attrs = { %$attrs }; |
74 | delete $inner_attrs->{$_} for qw/for collapse _prefetch_select _collapse_order_by select as/; |
75 | |
76 | |
77 | # bring over all non-collapse-induced order_by into the inner query (if any) |
78 | # the outer one will have to keep them all |
79 | delete $inner_attrs->{order_by}; |
80 | if (my $ord_cnt = @{$outer_attrs->{order_by}} - @{$outer_attrs->{_collapse_order_by}} ) { |
81 | $inner_attrs->{order_by} = [ |
82 | @{$outer_attrs->{order_by}}[ 0 .. $ord_cnt - 1] |
83 | ]; |
84 | } |
85 | |
d28bb90d |
86 | # generate the inner/outer select lists |
87 | # for inside we consider only stuff *not* brought in by the prefetch |
88 | # on the outside we substitute any function for its alias |
89 | my $outer_select = [ @$select ]; |
90 | my $inner_select = []; |
91 | for my $i (0 .. ( @$outer_select - @{$outer_attrs->{_prefetch_select}} - 1) ) { |
92 | my $sel = $outer_select->[$i]; |
93 | |
94 | if (ref $sel eq 'HASH' ) { |
95 | $sel->{-as} ||= $attrs->{as}[$i]; |
96 | $outer_select->[$i] = join ('.', $attrs->{alias}, ($sel->{-as} || "inner_column_$i") ); |
97 | } |
98 | |
99 | push @$inner_select, $sel; |
bb9bffea |
100 | |
101 | push @{$inner_attrs->{as}}, $attrs->{as}[$i]; |
d28bb90d |
102 | } |
103 | |
ea95892e |
104 | # construct the inner $from and lock it in a subquery |
48580715 |
105 | # we need to prune first, because this will determine if we need a group_by below |
53c29913 |
106 | # the fake group_by is so that the pruner throws away all non-selecting, non-restricting |
107 | # multijoins (since we def. do not care about those inside the subquery) |
ea95892e |
108 | |
109 | my $subq_joinspec = do { |
110 | |
111 | # must use it here regardless of user requests |
112 | local $self->{_use_join_optimizer} = 1; |
113 | |
114 | my $inner_from = $self->_prune_unused_joins ($from, $inner_select, $where, { |
115 | group_by => ['dummy'], %$inner_attrs, |
116 | }); |
117 | |
118 | # if a multi-type join was needed in the subquery - add a group_by to simulate the |
119 | # collapse in the subq |
0a3441ee |
120 | if ( |
121 | ! $inner_attrs->{group_by} |
122 | and |
123 | first { ! $_->[0]{-is_single} } (@{$inner_from}[1 .. $#$inner_from]) |
124 | ) { |
125 | $inner_attrs->{group_by} = $self->_group_over_selection ( |
126 | $inner_from, $inner_select, $inner_attrs->{order_by} |
127 | ); |
128 | } |
ea95892e |
129 | |
130 | # we already optimized $inner_from above |
131 | local $self->{_use_join_optimizer} = 0; |
132 | |
133 | # generate the subquery |
134 | my $subq = $self->_select_args_to_query ( |
135 | $inner_from, |
136 | $inner_select, |
137 | $where, |
138 | $inner_attrs, |
139 | ); |
140 | |
141 | +{ |
142 | -alias => $attrs->{alias}, |
143 | -source_handle => $inner_from->[0]{-source_handle}, |
144 | $attrs->{alias} => $subq, |
145 | }; |
d28bb90d |
146 | }; |
147 | |
148 | # Generate the outer from - this is relatively easy (really just replace |
149 | # the join slot with the subquery), with a major caveat - we can not |
150 | # join anything that is non-selecting (not part of the prefetch), but at |
151 | # the same time is a multi-type relationship, as it will explode the result. |
152 | # |
153 | # There are two possibilities here |
154 | # - either the join is non-restricting, in which case we simply throw it away |
155 | # - it is part of the restrictions, in which case we need to collapse the outer |
156 | # result by tackling yet another group_by to the outside of the query |
157 | |
052e8431 |
158 | $from = [ @$from ]; |
052e8431 |
159 | |
d28bb90d |
160 | # so first generate the outer_from, up to the substitution point |
161 | my @outer_from; |
162 | while (my $j = shift @$from) { |
53c29913 |
163 | $j = [ $j ] unless ref $j eq 'ARRAY'; # promote the head-from to an AoH |
164 | |
d28bb90d |
165 | if ($j->[0]{-alias} eq $attrs->{alias}) { # time to swap |
166 | push @outer_from, [ |
167 | $subq_joinspec, |
168 | @{$j}[1 .. $#$j], |
169 | ]; |
170 | last; # we'll take care of what's left in $from below |
171 | } |
172 | else { |
173 | push @outer_from, $j; |
174 | } |
175 | } |
176 | |
ea95892e |
177 | # scan the *remaining* from spec against different attributes, and see which joins are needed |
052e8431 |
178 | # in what role |
179 | my $outer_aliastypes = |
539ffe87 |
180 | $self->_resolve_aliastypes_from_select_args( $from, $outer_select, $where, $outer_attrs ); |
052e8431 |
181 | |
d28bb90d |
182 | # see what's left - throw away if not selecting/restricting |
183 | # also throw in a group_by if restricting to guard against |
184 | # cross-join explosions |
185 | # |
186 | while (my $j = shift @$from) { |
187 | my $alias = $j->[0]{-alias}; |
188 | |
1a736efb |
189 | if ($outer_aliastypes->{selecting}{$alias}) { |
d28bb90d |
190 | push @outer_from, $j; |
191 | } |
1a736efb |
192 | elsif ($outer_aliastypes->{restricting}{$alias}) { |
d28bb90d |
193 | push @outer_from, $j; |
539ffe87 |
194 | $outer_attrs->{group_by} ||= $outer_select unless $j->[0]{-is_single}; |
d28bb90d |
195 | } |
196 | } |
197 | |
198 | # demote the outer_from head |
199 | $outer_from[0] = $outer_from[0][0]; |
200 | |
201 | # This is totally horrific - the $where ends up in both the inner and outer query |
202 | # Unfortunately not much can be done until SQLA2 introspection arrives, and even |
203 | # then if where conditions apply to the *right* side of the prefetch, you may have |
204 | # to both filter the inner select (e.g. to apply a limit) and then have to re-filter |
205 | # the outer select to exclude joins you didin't want in the first place |
206 | # |
207 | # OTOH it can be seen as a plus: <ash> (notes that this query would make a DBA cry ;) |
208 | return (\@outer_from, $outer_select, $where, $outer_attrs); |
209 | } |
210 | |
1a736efb |
211 | # |
212 | # I KNOW THIS SUCKS! GET SQLA2 OUT THE DOOR SO THIS CAN DIE! |
213 | # |
ad630f4b |
214 | # Due to a lack of SQLA2 we fall back to crude scans of all the |
215 | # select/where/order/group attributes, in order to determine what |
216 | # aliases are neded to fulfill the query. This information is used |
217 | # throughout the code to prune unnecessary JOINs from the queries |
218 | # in an attempt to reduce the execution time. |
219 | # Although the method is pretty horrific, the worst thing that can |
1a736efb |
220 | # happen is for it to fail due to some scalar SQL, which in turn will |
221 | # result in a vocal exception. |
539ffe87 |
222 | sub _resolve_aliastypes_from_select_args { |
052e8431 |
223 | my ( $self, $from, $select, $where, $attrs ) = @_; |
546f1cd9 |
224 | |
ad630f4b |
225 | $self->throw_exception ('Unable to analyze custom {from}') |
226 | if ref $from ne 'ARRAY'; |
546f1cd9 |
227 | |
ad630f4b |
228 | # what we will return |
964a3c71 |
229 | my $aliases_by_type; |
546f1cd9 |
230 | |
ad630f4b |
231 | # see what aliases are there to work with |
232 | my $alias_list; |
539ffe87 |
233 | for (@$from) { |
234 | my $j = $_; |
ad630f4b |
235 | $j = $j->[0] if ref $j eq 'ARRAY'; |
539ffe87 |
236 | my $al = $j->{-alias} |
237 | or next; |
238 | |
239 | $alias_list->{$al} = $j; |
240 | $aliases_by_type->{multiplying}{$al} = 1 |
53c29913 |
241 | if ref($_) eq 'ARRAY' and ! $j->{-is_single}; # not array == {from} head == can't be multiplying |
546f1cd9 |
242 | } |
546f1cd9 |
243 | |
1a736efb |
244 | # get a column to source/alias map (including unqualified ones) |
245 | my $colinfo = $self->_resolve_column_info ($from); |
246 | |
ad630f4b |
247 | # set up a botched SQLA |
248 | my $sql_maker = $self->sql_maker; |
07f31d19 |
249 | |
3f5b99fe |
250 | local $sql_maker->{having_bind}; # these are throw away results |
251 | |
252 | # we can't scan properly without any quoting (\b doesn't cut it |
253 | # everywhere), so unless there is proper quoting set - use our |
254 | # own weird impossible character. |
255 | # Also in the case of no quoting, we need to explicitly disable |
256 | # name_sep, otherwise sorry nasty legacy syntax like |
257 | # { 'count(foo.id)' => { '>' => 3 } } will stop working >:( |
258 | local $sql_maker->{quote_char} = $sql_maker->{quote_char}; |
259 | local $sql_maker->{name_sep} = $sql_maker->{name_sep}; |
260 | |
261 | unless (defined $sql_maker->{quote_char} and length $sql_maker->{quote_char}) { |
262 | $sql_maker->{quote_char} = "\x00"; |
263 | $sql_maker->{name_sep} = ''; |
264 | } |
265 | |
266 | my ($lquote, $rquote, $sep) = map { quotemeta $_ } ($sql_maker->_quote_chars, $sql_maker->name_sep); |
07f31d19 |
267 | |
1a736efb |
268 | # generate sql chunks |
269 | my $to_scan = { |
270 | restricting => [ |
271 | $sql_maker->_recurse_where ($where), |
a7e643b1 |
272 | $sql_maker->_parse_rs_attrs ({ |
1a736efb |
273 | map { $_ => $attrs->{$_} } (qw/group_by having/) |
274 | }), |
275 | ], |
276 | selecting => [ |
7d3139ac |
277 | $self->_extract_order_columns ($attrs->{order_by}, $sql_maker), |
1a736efb |
278 | $sql_maker->_recurse_fields ($select), |
279 | ], |
280 | }; |
281 | |
282 | # throw away empty chunks |
283 | $_ = [ map { $_ || () } @$_ ] for values %$to_scan; |
284 | |
285 | # first loop through all fully qualified columns and get the corresponding |
286 | # alias (should work even if they are in scalarrefs) |
ad630f4b |
287 | for my $alias (keys %$alias_list) { |
1a736efb |
288 | my $al_re = qr/ |
3f5b99fe |
289 | $lquote $alias $rquote $sep |
1a736efb |
290 | | |
3f5b99fe |
291 | \b $alias \. |
1a736efb |
292 | /x; |
293 | |
1a736efb |
294 | for my $type (keys %$to_scan) { |
295 | for my $piece (@{$to_scan->{$type}}) { |
296 | $aliases_by_type->{$type}{$alias} = 1 if ($piece =~ $al_re); |
297 | } |
ad630f4b |
298 | } |
1a736efb |
299 | } |
300 | |
301 | # now loop through unqualified column names, and try to locate them within |
302 | # the chunks |
303 | for my $col (keys %$colinfo) { |
3f5b99fe |
304 | next if $col =~ / \. /x; # if column is qualified it was caught by the above |
1a736efb |
305 | |
3f5b99fe |
306 | my $col_re = qr/ $lquote $col $rquote /x; |
1a736efb |
307 | |
308 | for my $type (keys %$to_scan) { |
309 | for my $piece (@{$to_scan->{$type}}) { |
310 | $aliases_by_type->{$type}{$colinfo->{$col}{-source_alias}} = 1 if ($piece =~ $col_re); |
311 | } |
07f31d19 |
312 | } |
313 | } |
314 | |
315 | # Add any non-left joins to the restriction list (such joins are indeed restrictions) |
ad630f4b |
316 | for my $j (values %$alias_list) { |
07f31d19 |
317 | my $alias = $j->{-alias} or next; |
1a736efb |
318 | $aliases_by_type->{restricting}{$alias} = 1 if ( |
07f31d19 |
319 | (not $j->{-join_type}) |
320 | or |
321 | ($j->{-join_type} !~ /^left (?: \s+ outer)? $/xi) |
322 | ); |
323 | } |
324 | |
ea95892e |
325 | # mark all restricting/selecting join parents as such |
07f31d19 |
326 | # (e.g. join => { cds => 'tracks' } - tracks will need to bring cds too ) |
ea95892e |
327 | for my $type (qw/restricting selecting/) { |
328 | for my $alias (keys %{$aliases_by_type->{$type}||{}}) { |
964a3c71 |
329 | $aliases_by_type->{$type}{$_} = 1 |
faeb2407 |
330 | for (map { values %$_ } @{ $alias_list->{$alias}{-join_path} || [] }); |
07f31d19 |
331 | } |
332 | } |
ad630f4b |
333 | |
964a3c71 |
334 | return $aliases_by_type; |
07f31d19 |
335 | } |
336 | |
0a3441ee |
337 | sub _group_over_selection { |
338 | my ($self, $from, $select, $order_by) = @_; |
339 | |
340 | my $rs_column_list = $self->_resolve_column_info ($from); |
341 | |
342 | my (@group_by, %group_index); |
343 | |
344 | for (@$select) { |
345 | if (! ref($_) or ref ($_) ne 'HASH' ) { |
346 | push @group_by, $_; |
347 | $group_index{$_}++; |
348 | if ($rs_column_list->{$_} and $_ !~ /\./ ) { |
349 | # add a fully qualified version as well |
350 | $group_index{"$rs_column_list->{$_}{-source_alias}.$_"}++; |
351 | } |
352 | } |
353 | } |
354 | |
355 | # add any order_by parts that are not already present in the group_by |
356 | # we need to be careful not to add any named functions/aggregates |
357 | # i.e. select => [ ... { count => 'foo', -as 'foocount' } ... ] |
358 | for my $chunk ($self->_extract_order_columns($order_by)) { |
359 | # only consider real columns (for functions the user got to do an explicit group_by) |
360 | my $colinfo = $rs_column_list->{$chunk} |
361 | or next; |
362 | |
363 | $chunk = "$colinfo->{-source_alias}.$chunk" if $chunk !~ /\./; |
364 | push @group_by, $chunk unless $group_index{$chunk}++; |
365 | } |
366 | |
367 | return \@group_by; |
368 | } |
369 | |
d28bb90d |
370 | sub _resolve_ident_sources { |
371 | my ($self, $ident) = @_; |
372 | |
373 | my $alias2source = {}; |
374 | my $rs_alias; |
375 | |
376 | # the reason this is so contrived is that $ident may be a {from} |
377 | # structure, specifying multiple tables to join |
6298a324 |
378 | if ( blessed $ident && $ident->isa("DBIx::Class::ResultSource") ) { |
d28bb90d |
379 | # this is compat mode for insert/update/delete which do not deal with aliases |
380 | $alias2source->{me} = $ident; |
381 | $rs_alias = 'me'; |
382 | } |
383 | elsif (ref $ident eq 'ARRAY') { |
384 | |
385 | for (@$ident) { |
386 | my $tabinfo; |
387 | if (ref $_ eq 'HASH') { |
388 | $tabinfo = $_; |
389 | $rs_alias = $tabinfo->{-alias}; |
390 | } |
391 | if (ref $_ eq 'ARRAY' and ref $_->[0] eq 'HASH') { |
392 | $tabinfo = $_->[0]; |
393 | } |
394 | |
395 | $alias2source->{$tabinfo->{-alias}} = $tabinfo->{-source_handle}->resolve |
396 | if ($tabinfo->{-source_handle}); |
397 | } |
398 | } |
399 | |
400 | return ($alias2source, $rs_alias); |
401 | } |
402 | |
403 | # Takes $ident, \@column_names |
404 | # |
405 | # returns { $column_name => \%column_info, ... } |
406 | # also note: this adds -result_source => $rsrc to the column info |
407 | # |
09e14fdc |
408 | # If no columns_names are supplied returns info about *all* columns |
409 | # for all sources |
d28bb90d |
410 | sub _resolve_column_info { |
411 | my ($self, $ident, $colnames) = @_; |
412 | my ($alias2src, $root_alias) = $self->_resolve_ident_sources($ident); |
413 | |
52416317 |
414 | my (%seen_cols, @auto_colnames); |
d28bb90d |
415 | |
416 | # compile a global list of column names, to be able to properly |
417 | # disambiguate unqualified column names (if at all possible) |
418 | for my $alias (keys %$alias2src) { |
419 | my $rsrc = $alias2src->{$alias}; |
420 | for my $colname ($rsrc->columns) { |
421 | push @{$seen_cols{$colname}}, $alias; |
3f5b99fe |
422 | push @auto_colnames, "$alias.$colname" unless $colnames; |
d28bb90d |
423 | } |
424 | } |
425 | |
09e14fdc |
426 | $colnames ||= [ |
427 | @auto_colnames, |
428 | grep { @{$seen_cols{$_}} == 1 } (keys %seen_cols), |
429 | ]; |
430 | |
52416317 |
431 | my (%return, $colinfos); |
d28bb90d |
432 | foreach my $col (@$colnames) { |
52416317 |
433 | my ($source_alias, $colname) = $col =~ m/^ (?: ([^\.]+) \. )? (.+) $/x; |
d28bb90d |
434 | |
52416317 |
435 | # if the column was seen exactly once - we know which rsrc it came from |
436 | $source_alias ||= $seen_cols{$colname}[0] |
437 | if ($seen_cols{$colname} and @{$seen_cols{$colname}} == 1); |
d28bb90d |
438 | |
52416317 |
439 | next unless $source_alias; |
440 | |
441 | my $rsrc = $alias2src->{$source_alias} |
442 | or next; |
443 | |
444 | $return{$col} = { |
445 | %{ ( $colinfos->{$source_alias} ||= $rsrc->columns_info )->{$colname} }, |
d28bb90d |
446 | -result_source => $rsrc, |
52416317 |
447 | -source_alias => $source_alias, |
d28bb90d |
448 | }; |
449 | } |
450 | |
451 | return \%return; |
452 | } |
453 | |
289ac713 |
454 | # The DBIC relationship chaining implementation is pretty simple - every |
455 | # new related_relationship is pushed onto the {from} stack, and the {select} |
456 | # window simply slides further in. This means that when we count somewhere |
457 | # in the middle, we got to make sure that everything in the join chain is an |
458 | # actual inner join, otherwise the count will come back with unpredictable |
459 | # results (a resultset may be generated with _some_ rows regardless of if |
460 | # the relation which the $rs currently selects has rows or not). E.g. |
461 | # $artist_rs->cds->count - normally generates: |
462 | # SELECT COUNT( * ) FROM artist me LEFT JOIN cd cds ON cds.artist = me.artistid |
463 | # which actually returns the number of artists * (number of cds || 1) |
464 | # |
465 | # So what we do here is crawl {from}, determine if the current alias is at |
466 | # the top of the stack, and if not - make sure the chain is inner-joined down |
467 | # to the root. |
468 | # |
31a8aaaf |
469 | sub _inner_join_to_node { |
289ac713 |
470 | my ($self, $from, $alias) = @_; |
471 | |
472 | # subqueries and other oddness are naturally not supported |
473 | return $from if ( |
474 | ref $from ne 'ARRAY' |
475 | || |
476 | @$from <= 1 |
477 | || |
478 | ref $from->[0] ne 'HASH' |
479 | || |
480 | ! $from->[0]{-alias} |
481 | || |
7eb76996 |
482 | $from->[0]{-alias} eq $alias # this last bit means $alias is the head of $from - nothing to do |
289ac713 |
483 | ); |
484 | |
485 | # find the current $alias in the $from structure |
486 | my $switch_branch; |
487 | JOINSCAN: |
488 | for my $j (@{$from}[1 .. $#$from]) { |
489 | if ($j->[0]{-alias} eq $alias) { |
490 | $switch_branch = $j->[0]{-join_path}; |
491 | last JOINSCAN; |
492 | } |
493 | } |
494 | |
7eb76996 |
495 | # something else went quite wrong |
289ac713 |
496 | return $from unless $switch_branch; |
497 | |
498 | # So it looks like we will have to switch some stuff around. |
499 | # local() is useless here as we will be leaving the scope |
500 | # anyway, and deep cloning is just too fucking expensive |
7eb76996 |
501 | # So replace the first hashref in the node arrayref manually |
289ac713 |
502 | my @new_from = ($from->[0]); |
faeb2407 |
503 | my $sw_idx = { map { (values %$_), 1 } @$switch_branch }; #there's one k/v per join-path |
289ac713 |
504 | |
505 | for my $j (@{$from}[1 .. $#$from]) { |
506 | my $jalias = $j->[0]{-alias}; |
507 | |
508 | if ($sw_idx->{$jalias}) { |
509 | my %attrs = %{$j->[0]}; |
510 | delete $attrs{-join_type}; |
511 | push @new_from, [ |
512 | \%attrs, |
513 | @{$j}[ 1 .. $#$j ], |
514 | ]; |
515 | } |
516 | else { |
517 | push @new_from, $j; |
518 | } |
519 | } |
520 | |
521 | return \@new_from; |
522 | } |
523 | |
bac6c4fb |
524 | # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus |
525 | # a condition containing 'me' or other table prefixes will not work |
526 | # at all. What this code tries to do (badly) is introspect the condition |
527 | # and remove all column qualifiers. If it bails out early (returns undef) |
528 | # the calling code should try another approach (e.g. a subquery) |
529 | sub _strip_cond_qualifiers { |
530 | my ($self, $where) = @_; |
531 | |
532 | my $cond = {}; |
533 | |
534 | # No-op. No condition, we're updating/deleting everything |
535 | return $cond unless $where; |
536 | |
537 | if (ref $where eq 'ARRAY') { |
538 | $cond = [ |
539 | map { |
540 | my %hash; |
541 | foreach my $key (keys %{$_}) { |
542 | $key =~ /([^.]+)$/; |
543 | $hash{$1} = $_->{$key}; |
544 | } |
545 | \%hash; |
546 | } @$where |
547 | ]; |
548 | } |
549 | elsif (ref $where eq 'HASH') { |
550 | if ( (keys %$where) == 1 && ( (keys %{$where})[0] eq '-and' )) { |
551 | $cond->{-and} = []; |
552 | my @cond = @{$where->{-and}}; |
553 | for (my $i = 0; $i < @cond; $i++) { |
554 | my $entry = $cond[$i]; |
555 | my $hash; |
037e8dca |
556 | my $ref = ref $entry; |
557 | if ($ref eq 'HASH' or $ref eq 'ARRAY') { |
bac6c4fb |
558 | $hash = $self->_strip_cond_qualifiers($entry); |
559 | } |
037e8dca |
560 | elsif (! $ref) { |
bac6c4fb |
561 | $entry =~ /([^.]+)$/; |
562 | $hash->{$1} = $cond[++$i]; |
563 | } |
037e8dca |
564 | else { |
565 | $self->throw_exception ("_strip_cond_qualifiers() is unable to handle a condition reftype $ref"); |
566 | } |
bac6c4fb |
567 | push @{$cond->{-and}}, $hash; |
568 | } |
569 | } |
570 | else { |
571 | foreach my $key (keys %$where) { |
59ac6523 |
572 | if ($key eq '-or' && ref $where->{$key} eq 'ARRAY') { |
573 | $cond->{$key} = $self->_strip_cond_qualifiers($where->{$key}); |
574 | } |
575 | else { |
576 | $key =~ /([^.]+)$/; |
577 | $cond->{$1} = $where->{$key}; |
578 | } |
bac6c4fb |
579 | } |
580 | } |
581 | } |
582 | else { |
583 | return undef; |
584 | } |
585 | |
586 | return $cond; |
587 | } |
588 | |
7d3139ac |
589 | sub _extract_order_columns { |
1a736efb |
590 | my ($self, $order_by, $sql_maker) = @_; |
c0748280 |
591 | |
1a736efb |
592 | my $parser = sub { |
593 | my ($sql_maker, $order_by) = @_; |
c0748280 |
594 | |
1a736efb |
595 | return scalar $sql_maker->_order_by_chunks ($order_by) |
596 | unless wantarray; |
c0748280 |
597 | |
1a736efb |
598 | my @chunks; |
599 | for my $chunk (map { ref $_ ? @$_ : $_ } ($sql_maker->_order_by_chunks ($order_by) ) ) { |
600 | $chunk =~ s/\s+ (?: ASC|DESC ) \s* $//ix; |
601 | push @chunks, $chunk; |
602 | } |
603 | |
604 | return @chunks; |
605 | }; |
606 | |
607 | if ($sql_maker) { |
608 | return $parser->($sql_maker, $order_by); |
609 | } |
610 | else { |
611 | $sql_maker = $self->sql_maker; |
612 | local $sql_maker->{quote_char}; |
613 | return $parser->($sql_maker, $order_by); |
614 | } |
c0748280 |
615 | } |
bac6c4fb |
616 | |
d28bb90d |
617 | 1; |