Commit | Line | Data |
75d07914 |
1 | package DBIx::Class::Storage::DBI::MSSQL; |
3885cff6 |
2 | |
75d07914 |
3 | use strict; |
4 | use warnings; |
3885cff6 |
5 | |
fabbd5cc |
6 | use base qw/ |
7 | DBIx::Class::Storage::DBI::UniqueIdentifier |
8 | DBIx::Class::Storage::DBI::IdentityInsert |
9 | /; |
2ad62d97 |
10 | use mro 'c3'; |
fabbd5cc |
11 | |
ed7ab0f4 |
12 | use Try::Tiny; |
6298a324 |
13 | use List::Util 'first'; |
fd323bf1 |
14 | use namespace::clean; |
3885cff6 |
15 | |
7b1b2582 |
16 | __PACKAGE__->mk_group_accessors(simple => qw/ |
25d3127d |
17 | _identity _identity_method _no_scope_identity_query |
7b1b2582 |
18 | /); |
19 | |
d5dedbd6 |
20 | __PACKAGE__->sql_maker_class('DBIx::Class::SQLMaker::MSSQL'); |
ac93965c |
21 | |
2b8cc2f2 |
22 | __PACKAGE__->sql_quote_char([qw/[ ]/]); |
23 | |
6f7a118e |
24 | __PACKAGE__->datetime_parser_type ( |
25 | 'DBIx::Class::Storage::DBI::MSSQL::DateTime::Format' |
26 | ); |
27 | |
40d8d018 |
28 | __PACKAGE__->new_guid('NEWID()'); |
29 | |
3e4a74aa |
30 | sub __sql_server_x_or_higher { |
31 | my ($self, $version) = @_; |
32 | |
fe5a0374 |
33 | if (exists $_[0]->_server_info->{normalized_dbms_version}) { |
3e4a74aa |
34 | if ($_[0]->_server_info->{normalized_dbms_version} >= $version) { |
fe5a0374 |
35 | return 1 |
36 | } else { |
37 | return 0 |
38 | } |
39 | } |
40 | return undef; |
41 | } |
42 | |
bfff1ef0 |
43 | sub __offset_bindtype { +{ dbd_attrs => DBI::SQL_INTEGER() } } |
44 | sub __rows_bindtype { +{ dbd_attrs => DBI::SQL_INTEGER() } } |
45 | |
3e4a74aa |
46 | sub _sql_server_2005_or_higher { shift->__sql_server_x_or_higher(9) } |
47 | sub _sql_server_2012_or_higher { shift->__sql_server_x_or_higher(11) } |
48 | |
5a77aa8b |
49 | sub _prep_for_execute { |
50 | my $self = shift; |
0e773352 |
51 | my ($op, $ident, $args) = @_; |
5a77aa8b |
52 | |
53 | # cast MONEY values properly |
54 | if ($op eq 'insert' || $op eq 'update') { |
55 | my $fields = $args->[0]; |
5a77aa8b |
56 | |
52416317 |
57 | my $colinfo = $ident->columns_info([keys %$fields]); |
58 | |
5a77aa8b |
59 | for my $col (keys %$fields) { |
1537084d |
60 | # $ident is a result source object with INSERT/UPDATE ops |
52416317 |
61 | if ( |
62 | $colinfo->{$col}{data_type} |
63 | && |
64 | $colinfo->{$col}{data_type} =~ /^money\z/i |
65 | ) { |
5a77aa8b |
66 | my $val = $fields->{$col}; |
67 | $fields->{$col} = \['CAST(? AS MONEY)', [ $col => $val ]]; |
68 | } |
69 | } |
70 | } |
71 | |
72 | my ($sql, $bind) = $self->next::method (@_); |
73 | |
fabbd5cc |
74 | # SELECT SCOPE_IDENTITY only works within a statement scope. We |
4a0eed52 |
75 | # must try to always use this particular idiom first, as it is the |
fabbd5cc |
76 | # only one that guarantees retrieving the correct id under high |
77 | # concurrency. When this fails we will fall back to whatever secondary |
78 | # retrieval method is specified in _identity_method, but at this |
79 | # point we don't have many guarantees we will get what we expected. |
80 | # http://msdn.microsoft.com/en-us/library/ms190315.aspx |
81 | # http://davidhayden.com/blog/dave/archive/2006/01/17/2736.aspx |
25d3127d |
82 | if ($self->_perform_autoinc_retrieval and not $self->_no_scope_identity_query) { |
384b8bce |
83 | $sql .= "\nSELECT SCOPE_IDENTITY()"; |
5a77aa8b |
84 | } |
85 | |
86 | return ($sql, $bind); |
87 | } |
88 | |
89 | sub _execute { |
90 | my $self = shift; |
5a77aa8b |
91 | |
fabbd5cc |
92 | # always list ctx - we need the $sth |
0e773352 |
93 | my ($rv, $sth, @bind) = $self->next::method(@_); |
1537084d |
94 | |
fabbd5cc |
95 | if ($self->_perform_autoinc_retrieval) { |
5a77aa8b |
96 | |
25d3127d |
97 | # attempt to bring back the result of SELECT SCOPE_IDENTITY() we tacked |
1537084d |
98 | # on in _prep_for_execute above |
25d3127d |
99 | my $identity; |
100 | |
101 | # we didn't even try on ftds |
102 | unless ($self->_no_scope_identity_query) { |
103 | ($identity) = try { $sth->fetchrow_array }; |
104 | $sth->finish; |
105 | } |
ed8de058 |
106 | |
1537084d |
107 | # SCOPE_IDENTITY failed, but we can do something else |
108 | if ( (! $identity) && $self->_identity_method) { |
109 | ($identity) = $self->_dbh->selectrow_array( |
110 | 'select ' . $self->_identity_method |
111 | ); |
112 | } |
7b1b2582 |
113 | |
1537084d |
114 | $self->_identity($identity); |
7b1b2582 |
115 | } |
116 | |
1537084d |
117 | return wantarray ? ($rv, $sth, @bind) : $rv; |
7b1b2582 |
118 | } |
5a77aa8b |
119 | |
7b1b2582 |
120 | sub last_insert_id { shift->_identity } |
5a77aa8b |
121 | |
f0bd60fc |
122 | # |
e74c68ce |
123 | # MSSQL is retarded wrt ordered subselects. One needs to add a TOP |
6a247f33 |
124 | # to *all* subqueries, but one also *can't* use TOP 100 PERCENT |
e74c68ce |
125 | # http://sqladvice.com/forums/permalink/18496/22931/ShowThread.aspx#22931 |
f0bd60fc |
126 | # |
127 | sub _select_args_to_query { |
b928a9d5 |
128 | #my ($self, $ident, $select, $cond, $attrs) = @_; |
f0bd60fc |
129 | my $self = shift; |
b928a9d5 |
130 | my $attrs = $_[3]; |
f0bd60fc |
131 | |
b928a9d5 |
132 | my $sql_bind = $self->next::method (@_); |
f0bd60fc |
133 | |
b8d88d9b |
134 | # see if this is an ordered subquery |
aca481d8 |
135 | if ( |
b928a9d5 |
136 | $$sql_bind->[0] !~ /^ \s* \( \s* SELECT \s+ TOP \s+ \d+ \s+ /xi |
137 | and |
bac358c9 |
138 | scalar $self->_extract_order_criteria ($attrs->{order_by}) |
aca481d8 |
139 | ) { |
6de07ea3 |
140 | $self->throw_exception( |
e705f529 |
141 | 'An ordered subselect encountered - this is not safe! Please see "Ordered Subselects" in DBIx::Class::Storage::DBI::MSSQL' |
142 | ) unless $attrs->{unsafe_subselect_ok}; |
b928a9d5 |
143 | |
144 | $$sql_bind->[0] =~ s/^ \s* \( \s* SELECT (?=\s) / '(SELECT TOP ' . $self->sql_maker->__max_int /exi; |
f0bd60fc |
145 | } |
146 | |
b928a9d5 |
147 | $sql_bind; |
f0bd60fc |
148 | } |
149 | |
150 | |
4c0f4206 |
151 | # savepoint syntax is the same as in Sybase ASE |
152 | |
90d7422f |
153 | sub _exec_svp_begin { |
4c0f4206 |
154 | my ($self, $name) = @_; |
155 | |
90d7422f |
156 | $self->_dbh->do("SAVE TRANSACTION $name"); |
4c0f4206 |
157 | } |
158 | |
159 | # A new SAVE TRANSACTION with the same name releases the previous one. |
90d7422f |
160 | sub _exec_svp_release { 1 } |
4c0f4206 |
161 | |
90d7422f |
162 | sub _exec_svp_rollback { |
4c0f4206 |
163 | my ($self, $name) = @_; |
164 | |
90d7422f |
165 | $self->_dbh->do("ROLLBACK TRANSACTION $name"); |
4c0f4206 |
166 | } |
167 | |
eb0323df |
168 | sub sqlt_type { 'SQLServer' } |
169 | |
6a247f33 |
170 | sub sql_limit_dialect { |
50772633 |
171 | my $self = shift; |
eb0323df |
172 | |
f895c500 |
173 | my $supports_ofn = $self->_sql_server_2012_or_higher; |
174 | |
175 | unless (defined $supports_ofn) { |
176 | # User is connecting via DBD::Sybase and has no permission to run |
177 | # stored procedures like xp_msver, or version detection failed for some |
178 | # other reason. |
179 | # So, we use a query to check if OFN is implemented. |
180 | try { |
181 | $self->_get_dbh->selectrow_array('SELECT 1 ORDER BY 1 OFFSET 0 ROWS'); |
182 | $supports_ofn = 1; |
183 | }; |
184 | } |
185 | return 'OffsetFetchNext' if $supports_ofn; |
186 | |
fe5a0374 |
187 | my $supports_rno = $self->_sql_server_2005_or_higher; |
ff153e24 |
188 | |
fe5a0374 |
189 | unless (defined $supports_rno) { |
6a247f33 |
190 | # User is connecting via DBD::Sybase and has no permission to run |
191 | # stored procedures like xp_msver, or version detection failed for some |
192 | # other reason. |
193 | # So, we use a query to check if RNO is implemented. |
194 | try { |
195 | $self->_get_dbh->selectrow_array('SELECT row_number() OVER (ORDER BY rand())'); |
196 | $supports_rno = 1; |
197 | }; |
50772633 |
198 | } |
f895c500 |
199 | return 'RowNumberOver' if $supports_rno; |
e76e7b5c |
200 | |
f895c500 |
201 | return 'Top'; |
ed8de058 |
202 | } |
3885cff6 |
203 | |
ecdf1ac8 |
204 | sub _ping { |
205 | my $self = shift; |
206 | |
207 | my $dbh = $self->_dbh or return 0; |
208 | |
209 | local $dbh->{RaiseError} = 1; |
210 | local $dbh->{PrintError} = 0; |
211 | |
52b420dd |
212 | return try { |
ecdf1ac8 |
213 | $dbh->do('select 1'); |
52b420dd |
214 | 1; |
ed7ab0f4 |
215 | } catch { |
52b420dd |
216 | 0; |
ecdf1ac8 |
217 | }; |
ecdf1ac8 |
218 | } |
219 | |
fb95dc4d |
220 | package # hide from PAUSE |
221 | DBIx::Class::Storage::DBI::MSSQL::DateTime::Format; |
222 | |
fd323bf1 |
223 | my $datetime_format = '%Y-%m-%d %H:%M:%S.%3N'; # %F %T |
fb95dc4d |
224 | my $smalldatetime_format = '%Y-%m-%d %H:%M:%S'; |
225 | |
226 | my ($datetime_parser, $smalldatetime_parser); |
227 | |
228 | sub parse_datetime { |
229 | shift; |
230 | require DateTime::Format::Strptime; |
231 | $datetime_parser ||= DateTime::Format::Strptime->new( |
232 | pattern => $datetime_format, |
233 | on_error => 'croak', |
234 | ); |
235 | return $datetime_parser->parse_datetime(shift); |
236 | } |
237 | |
238 | sub format_datetime { |
239 | shift; |
240 | require DateTime::Format::Strptime; |
241 | $datetime_parser ||= DateTime::Format::Strptime->new( |
242 | pattern => $datetime_format, |
243 | on_error => 'croak', |
244 | ); |
245 | return $datetime_parser->format_datetime(shift); |
246 | } |
247 | |
248 | sub parse_smalldatetime { |
249 | shift; |
250 | require DateTime::Format::Strptime; |
251 | $smalldatetime_parser ||= DateTime::Format::Strptime->new( |
252 | pattern => $smalldatetime_format, |
253 | on_error => 'croak', |
254 | ); |
255 | return $smalldatetime_parser->parse_datetime(shift); |
256 | } |
257 | |
258 | sub format_smalldatetime { |
259 | shift; |
260 | require DateTime::Format::Strptime; |
261 | $smalldatetime_parser ||= DateTime::Format::Strptime->new( |
262 | pattern => $smalldatetime_format, |
263 | on_error => 'croak', |
264 | ); |
265 | return $smalldatetime_parser->format_datetime(shift); |
266 | } |
267 | |
75d07914 |
268 | 1; |
3885cff6 |
269 | |
75d07914 |
270 | =head1 NAME |
3885cff6 |
271 | |
5a77aa8b |
272 | DBIx::Class::Storage::DBI::MSSQL - Base Class for Microsoft SQL Server support |
273 | in DBIx::Class |
3885cff6 |
274 | |
75d07914 |
275 | =head1 SYNOPSIS |
3885cff6 |
276 | |
5a77aa8b |
277 | This is the base class for Microsoft SQL Server support, used by |
278 | L<DBIx::Class::Storage::DBI::ODBC::Microsoft_SQL_Server> and |
279 | L<DBIx::Class::Storage::DBI::Sybase::Microsoft_SQL_Server>. |
eb0323df |
280 | |
5a77aa8b |
281 | =head1 IMPLEMENTATION NOTES |
eb0323df |
282 | |
fd05d10a |
283 | =head2 IDENTITY information |
284 | |
5a77aa8b |
285 | Microsoft SQL Server supports three methods of retrieving the IDENTITY |
286 | value for inserted row: IDENT_CURRENT, @@IDENTITY, and SCOPE_IDENTITY(). |
287 | SCOPE_IDENTITY is used here because it is the safest. However, it must |
288 | be called is the same execute statement, not just the same connection. |
eb0323df |
289 | |
5a77aa8b |
290 | So, this implementation appends a SELECT SCOPE_IDENTITY() statement |
291 | onto each INSERT to accommodate that requirement. |
eb0323df |
292 | |
7b1b2582 |
293 | C<SELECT @@IDENTITY> can also be used by issuing: |
294 | |
295 | $self->_identity_method('@@identity'); |
296 | |
08cdc412 |
297 | it will only be used if SCOPE_IDENTITY() fails. |
298 | |
299 | This is more dangerous, as inserting into a table with an on insert trigger that |
300 | inserts into another table with an identity will give erroneous results on |
301 | recent versions of SQL Server. |
7b1b2582 |
302 | |
c84189e1 |
303 | =head2 identity insert |
fd05d10a |
304 | |
305 | Be aware that we have tried to make things as simple as possible for our users. |
c84189e1 |
306 | For MSSQL that means that when a user tries to create a row, while supplying an |
307 | explicit value for an autoincrementing column, we will try to issue the |
308 | appropriate database call to make this possible, namely C<SET IDENTITY_INSERT |
309 | $table_name ON>. Unfortunately this operation in MSSQL requires the |
310 | C<db_ddladmin> privilege, which is normally not included in the standard |
311 | write-permissions. |
fd05d10a |
312 | |
d74f2da9 |
313 | =head2 Ordered Subselects |
6de07ea3 |
314 | |
d74f2da9 |
315 | If you attempted the following query (among many others) in Microsoft SQL |
316 | Server |
6de07ea3 |
317 | |
6de07ea3 |
318 | $rs->search ({}, { |
6de07ea3 |
319 | prefetch => 'relation', |
320 | rows => 2, |
321 | offset => 3, |
322 | }); |
323 | |
d74f2da9 |
324 | You may be surprised to receive an exception. The reason for this is a quirk |
325 | in the MSSQL engine itself, and sadly doesn't have a sensible workaround due |
326 | to the way DBIC is built. DBIC can do truly wonderful things with the aid of |
327 | subselects, and does so automatically when necessary. The list of situations |
328 | when a subselect is necessary is long and still changes often, so it can not |
329 | be exhaustively enumerated here. The general rule of thumb is a joined |
330 | L<has_many|DBIx::Class::Relationship/has_many> relationship with limit/group |
331 | applied to the left part of the join. |
332 | |
333 | In its "pursuit of standards" Microsft SQL Server goes to great lengths to |
334 | forbid the use of ordered subselects. This breaks a very useful group of |
335 | searches like "Give me things number 4 to 6 (ordered by name), and prefetch |
336 | all their relations, no matter how many". While there is a hack which fools |
337 | the syntax checker, the optimizer may B<still elect to break the subselect>. |
338 | Testing has determined that while such breakage does occur (the test suite |
339 | contains an explicit test which demonstrates the problem), it is relative |
340 | rare. The benefits of ordered subselects are on the other hand too great to be |
341 | outright disabled for MSSQL. |
6de07ea3 |
342 | |
343 | Thus compromise between usability and perfection is the MSSQL-specific |
69a8b315 |
344 | L<resultset attribute|DBIx::Class::ResultSet/ATTRIBUTES> C<unsafe_subselect_ok>. |
6de07ea3 |
345 | It is deliberately not possible to set this on the Storage level, as the user |
48580715 |
346 | should inspect (and preferably regression-test) the return of every such |
d74f2da9 |
347 | ResultSet individually. The example above would work if written like: |
348 | |
349 | $rs->search ({}, { |
69a8b315 |
350 | unsafe_subselect_ok => 1, |
d74f2da9 |
351 | prefetch => 'relation', |
352 | rows => 2, |
353 | offset => 3, |
354 | }); |
6de07ea3 |
355 | |
356 | If it is possible to rewrite the search() in a way that will avoid the need |
357 | for this flag - you are urged to do so. If DBIC internals insist that an |
d74f2da9 |
358 | ordered subselect is necessary for an operation, and you believe there is a |
48580715 |
359 | different/better way to get the same result - please file a bugreport. |
6de07ea3 |
360 | |
5a77aa8b |
361 | =head1 AUTHOR |
3885cff6 |
362 | |
548d1627 |
363 | See L<DBIx::Class/AUTHOR> and L<DBIx::Class/CONTRIBUTORS>. |
3885cff6 |
364 | |
75d07914 |
365 | =head1 LICENSE |
3885cff6 |
366 | |
75d07914 |
367 | You may distribute this code under the same terms as Perl itself. |
3885cff6 |
368 | |
75d07914 |
369 | =cut |