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