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