1ORLite(3) User Contributed Perl Documentation ORLite(3)
2
6 ORLite - Extremely light weight SQLite-specific ORM
7
9 package Foo;
10 # Simplest possible usage
12 use strict;
14 use ORLite 'data/sqlite.db';
15 my @awesome = Foo::Person->select(
17 'where first_name = ?',
18 'Adam',
19 );
20 package Bar;
22 # All available options enabled or specified.
24 # Some options shown are mutually exclusive,
25 # this code would not actually run.
26 use ORLite {
28 package => 'My::ORM',
29 file => 'data/sqlite.db',
30 user_version => 12,
31 readonly => 1,
32 create => sub {
33 my $dbh = shift;
34 $dbh->do('CREATE TABLE foo ( bar TEXT NOT NULL )');
35 },
36 tables => [ 'table1', 'table2' ],
37 cleanup => 'VACUUM',
38 prune => 1,
39 };
40
42 SQLite is a light single file SQL database that provides an excellent
43 platform for embedded storage of structured data.
44 However, while it is superficially similar to a regular server-side SQL
46 database, SQLite has some significant attributes that make using it
47 like a traditional database difficult.
48 For example, SQLite is extremely fast to connect to compared to server
50 databases (1000 connections per second is not unknown) and is
51 particularly bad at concurrency, as it can only lock transactions at a
52 database-wide level.
53 This role as a superfast internal data store can clash with the roles
55 and designs of traditional object-relational modules like Class::DBI or
56 DBIx::Class.
57 What this situation would seem to need is an object-relation system
59 that is designed specifically for SQLite and is aligned with its
60 idiosyncracies.
61 ORLite is an object-relation system specifically tailored for SQLite
63 that follows many of the same principles as the ::Tiny series of
64 modules and has a design and feature set that aligns directly to the
65 capabilities of SQLite.
66 Further documentation will be available at a later time, but the
68 synopsis gives a pretty good idea of how it works.
69 How ORLite Works
71 ORLite discovers the schema of a SQLite database, and then generates
72 the code for a complete set of classes that let you work with the
73 objects stored in that database.
74 In the simplest form, your target root package "uses" ORLite, which
76 will do the schema discovery and code generation at compile-time.
77 When called, ORLite generates two types of packages.
79 Firstly, it builds database connectivity, transaction support, and
81 other purely database level functionality into your root namespace.
82 Secondly, it will create one sub-package underneath the namespace of
84 the root module for each table or view it finds in the database.
85 Once the basic table support has been generated, it will also try to
87 load an "overlay" module of the same name. Thus, by created a
88 Foo::TableName module on disk containing "extra" code, you can extend
89 the original and add additional functionality to it.
90
92 ORLite takes a set of options for the class construction at compile
93 time as a HASH parameter to the "use" line.
94 As a convenience, you can pass just the name of an existing SQLite file
96 to load, and ORLite will apply defaults to all other options.
97 # The following are equivalent
99 use ORLite $filename;
101 use ORLite {
103 file => $filename,
104 };
105 The behaviour of each of the options is as follows:
107 package
109 The optional "package" parameter is used to provide the Perl root
110 namespace to generate the code for. This class does not need to exist
111 as a module on disk, nor does it need to have anything loaded or in the
112 namespace.
113 By default, the package used is the package that is calling ORLite's
115 import method (typically via the "use ORLite { ... }" line).
116 file
118 The compulsory "file" parameter (the only compulsory parameter)
119 provides the path to the SQLite file to use for the ORM class tree.
120 If the file already exists, it must be a valid SQLite file match that
122 supported by the version of DBD::SQLite that is installed on your
123 system.
124 ORLite will throw an exception if the file does not exist, unless you
126 also provide the "create" option to signal that ORLite should create a
127 new SQLite file on demand.
128 If the "create" option is provided, the path provided must be
130 creatable. When creating the database, ORLite will also create any
131 missing directories as needed.
132 user_version
134 When working with ORLite, the biggest risk to the stability of your
135 code is often the reliability of the SQLite schema structure over time.
136 When the database schema changes the code generated by ORLite will also
138 change. This can easily result in an unexpected change in the API of
139 your class tree, breaking the code that sits on top of those generated
140 APIs.
141 To resolve this, ORLite supports a feature called schema version-
143 locking.
144 Via the "user_version" SQLite pragma, you can set a revision for your
146 database schema, increasing the number each time to make a non-trivial
147 chance to your schema.
148 SQLite> PRAGMA user_version = 7
150 When creating your ORLite package, you should specificy this schema
152 version number via the "user_version" option.
153 use ORLite {
155 file => $filename,
156 user_version => 7,
157 };
158 When connecting to the SQLite database, the "user_version" you provide
160 will be checked against the version in the schema. If the versions do
161 not match, then the schema has unexpectedly changed, and the code that
162 is generated by ORLite would be different to the expected API.
163 Rather than risk potentially destructive errors caused by the changing
165 code, ORLite will simply refuse to run and throw an exception.
166 Thus, using the "user_version" feature allows you to write code against
168 a SQLite database with high-certainty that it will continue to work. Or
169 at the very least, that should the SQLite schema change in the future
170 your code fill fail quickly and safely instead of running away and
171 causing unknown behaviour.
172 By default, the "user_version" option is false and the value of the
174 SQLite "PRAGMA user_version" will not be checked.
175 readonly
177 To conserve memory and reduce complexity, ORLite will generate the API
178 differently based on the writability of the SQLite database.
179 Features like transaction support and methods that result in "INSERT",
181 "UPDATE" and "DELETE" queries will only be added if they can actually
182 be run, resulting in an immediate "no such method" exception at the
183 Perl level instead of letting the application do more work only to hit
184 an inevitable SQLite error.
185 By default, the "readonly" option is based on the filesystem
187 permissions of the SQLite database (which matches SQLite's own
188 writability behaviour).
189 However the "readonly" option can be explicitly provided if you wish.
191 Generally you would do this if you are working with a read-write
192 database, but you only plan to read from it.
193 Forcing "readonly" to true will halve the size of the code that is
195 generated to produce your ORM, reducing the size of any auto-generated
196 API documentation using ORLite::Pod by a similar amount.
197 It also ensures that this process will only take shared read locks on
199 the database (preventing the chance of creating a dead-lock on the
200 SQLite database).
201 create
203 The "create" option is used to expand ORLite beyond just consuming
204 other people's databases to produce and operating on databases user the
205 direct control of your code.
206 The "create" option supports two alternative forms.
208 If "create" is set to a simple true value, an empty SQLite file will be
210 created if the location provided in the "file" option does not exist.
211 If "create" is set to a "CODE" reference, this function will be
213 executed on the new database before ORLite attempts to scan the schema.
214 The "CODE" reference will be passed a plain DBI connection handle,
216 which you should operate on normally. Note that because "create" is
217 fired before the code generation phase, none of the functionality
218 produced by the generated classes is available during the execution of
219 the "create" code.
220 The use of "create" option is incompatible with the "readonly" option.
222 tables
224 The "tables" option should be a reference to an array containing a list
225 of table names. For large or complex SQLite databases where you only
226 need to make use of a fraction of the schema limiting the set of tables
227 will reduce both the startup time needed to scan the structure of the
228 SQLite schema, and reduce the memory cost of the class tree.
229 If the "tables" option is not provided, ORLite will attempt to produce
231 a class for every table in the main schema that is not prefixed with
232 with "sqlite_".
233 cache
235 use ORLite {
236 file => 'dbi:SQLite:sqlite.db',
237 user_version => 2,
238 cache => 'cache/directory',
239 };
240 The "cache" option is used to reduce the time needed to scan the SQLite
242 database table structures and generate the code for them, by saving the
243 generated code to a cache directory and loading from that file instead
244 of generating it each time from scratch.
245 cleanup
247 When working with embedded SQLite databases containing rapidly changing
248 state data, it is important for database performance and general health
249 to make sure you VACUUM or ANALYZE the database regularly.
250 The "cleanup" option should be a single literal SQL statement.
252 If provided, this statement will be automatically run on the database
254 during "END"-time, after the last transaction has been completed.
255 This will typically either by a full 'VACUUM ANALYZE' or the more
257 simple 'VACUUM'.
258 prune
260 In some situation, such as during test scripts, an application will
261 only need the created SQLite database temporarily. In these situations,
262 the "prune" option can be provided to instruct ORLite to delete the
263 SQLite database when the program ends.
264 If any directories were made in order to create the SQLite file, these
266 directories will be cleaned up and removed as well.
267 If "prune" is enabled, you should generally not use "cleanup" as any
269 cleanup operation will be made pointless when "prune" deletes the file.
270 By default, the "prune" option is set to false.
272 shim
274 In some situtations you may wish to make extensive changes to the
275 behaviour of the classes and methods generated by ORLite. Under normal
276 circumstances all code is generated into the table class directly,
277 which can make overriding method difficult.
278 The "shim" option will make ORLite generate all of it's methods into a
280 seperate "Foo::TableName::Shim" class, and leave the main table class
281 "Foo::TableName" as a transparent subclass of the shim.
282 This allows you to alter the behaviour of a table class without having
284 to do nasty tricks with symbol tables in order to alter or replace
285 methods.
286 package My::Person;
288 # Write a log message when we create a new object
290 sub create {
291 my $class = shift;
292 my $self = SUPER::create(@_);
293 my $name = $self->name;
294 print LOG "Created new person '$name'\n";
295 return $self;
296 }
297 The "shim" option is global. It will alter the structure of all table
299 classes at once. However, unless you are making alterations to a class
300 the impact of this different class structure should be zero.
301 unicode
303 You can use this option to tell ORLite that your database uses unicode.
304 At the moment, it just enables the "sqlite_unicode" option while
306 connecting to your database. There'll be more in the future.
307
309 All ORLite root packages receive an identical set of methods for
310 controlling connections to the database, transactions, and the issueing
311 of queries of various types to the database.
312 The example root package Foo::Bar is used in any examples.
314 All methods are static, ORLite does not allow the creation of a
316 Foo::Bar object (although you may wish to add this capability
317 yourself).
318 dsn
320 my $string = Foo::Bar->dsn;
321 The "dsn" accessor returns the dbi connection string used to connect to
323 the SQLite database as a string.
324 dbh
326 my $handle = Foo::Bar->dbh;
327 To reliably prevent potential SQLite deadlocks resulting from multiple
329 connections in a single process, each ORLite package will only ever
330 maintain a single connection to the database.
331 During a transaction, this will be the same (cached) database handle.
333 Although in most situations you should not need a direct DBI connection
335 handle, the "dbh" method provides a method for getting a direct
336 connection in a way that is compatible with ORLite's connection
337 management.
338 Please note that these connections should be short-lived, you should
340 never hold onto a connection beyond the immediate scope.
341 The transaction system in ORLite is specifically designed so that code
343 using the database should never have to know whether or not it is in a
344 transation.
345 Because of this, you should never call the ->disconnect method on the
347 database handles yourself, as the handle may be that of a currently
348 running transaction.
349 Further, you should do your own transaction management on a handle
351 provided by the <dbh> method.
352 In cases where there are extreme needs, and you absolutely have to
354 violate these connection handling rules, you should create your own
355 completely manual DBI->connect call to the database, using the connect
356 string provided by the "dsn" method.
357 The "dbh" method returns a DBI::db object, or throws an exception on
359 error.
360 connect
362 my $dbh = Foo::Bar->connect;
363 The "connect" method is provided for the (extremely rare) situation in
365 which you need a raw connection to the database, evading the normal
366 tracking and management provided of the ORM.
367 The use of raw connections in this manner is strongly discouraged, as
369 you can create fatal deadlocks in SQLite if either the core ORM or the
370 raw connection uses a transaction at any time.
371 To summarise, do not use this method unless you REALLY know what you
373 are doing.
374 YOU HAVE BEEN WARNED!
376 connected
378 my $active = Foo::Bar->connected;
379 The "connected" method provides introspection of the connection status
381 of the library. It returns true if there is any connection or
382 transaction open to the database, or false otherwise.
383 begin
385 Foo::Bar->begin;
386 The "begin" method indicates the start of a transaction.
388 In the same way that ORLite allows only a single connection, likewise
390 it allows only a single application-wide transaction.
391 No indication is given as to whether you are currently in a transaction
393 or not, all code should be written neutrally so that it works either
394 way or doesn't need to care.
395 Returns true or throws an exception on error.
397 While transaction support is always built for every ORLite-generated
399 class tree, if the database is opened "readonly" the "commit" method
400 will not exist at all in the API, and your only way of ending the
401 transaction (and the resulting persistent connection) will be
402 "rollback".
403 commit
405 Foo::Bar->commit;
406 The "commit" method commits the current transaction. If called outside
408 of a current transaction, it is accepted and treated as a null
409 operation.
410 Once the commit has been completed, the database connection falls back
412 into auto-commit state. If you wish to immediately start another
413 transaction, you will need to issue a separate ->begin call.
414 Returns true or throws an exception on error.
416 commit_begin
418 Foo::Bar->begin;
419 # Code for the first transaction...
421 Foo::Bar->commit_begin;
423 # Code for the last transaction...
425 Foo::Bar->commit;
427 By default, ORLite-generated code uses opportunistic connections.
429 Every <select> you call results in a fresh DBI "connect", and a
431 "disconnect" occurs after query processing and before the data is
432 returned. Connections are only held open indefinitely during a
433 transaction, with an immediate "disconnect" after your "commit".
434 This makes ORLite very easy to use in an ad-hoc manner, but can have
436 performance implications.
437 While SQLite itself can handle 1000 connections per second, the
439 repeated destruction and repopulation of SQLite's data page caches
440 between your statements (or between transactions) can slow things down
441 dramatically.
442 The "commit_begin" method is used to "commit" the current transaction
444 and immediately start a new transaction, without disconnecting from the
445 database.
446 Its exception behaviour and return value is identical to that of a
448 plain "commit" call.
449 rollback
451 The "rollback" method rolls back the current transaction. If called
452 outside of a current transaction, it is accepted and treated as a null
453 operation.
454 Once the rollback has been completed, the database connection falls
456 back into auto-commit state. If you wish to immediately start another
457 transaction, you will need to issue a separate ->begin call.
458 If a transaction exists at END-time as the process exits, it will be
460 automatically rolled back.
461 Returns true or throws an exception on error.
463 rollback_begin
465 Foo::Bar->begin;
466 # Code for the first transaction...
468 Foo::Bar->rollback_begin;
470 # Code for the last transaction...
472 Foo::Bar->commit;
474 By default, ORLite-generated code uses opportunistic connections.
476 Every <select> you call results in a fresh DBI "connect", and a
478 "disconnect" occurs after query processing and before the data is
479 returned. Connections are only held open indefinitely during a
480 transaction, with an immediate "disconnect" after your "commit".
481 This makes ORLite very easy to use in an ad-hoc manner, but can have
483 performance implications.
484 While SQLite itself can handle 1000 connections per second, the
486 repeated destruction and repopulation of SQLite's data page caches
487 between your statements (or between transactions) can slow things down
488 dramatically.
489 The "rollback_begin" method is used to "rollback" the current
491 transaction and immediately start a new transaction, without
492 disconnecting from the database.
493 Its exception behaviour and return value is identical to that of a
495 plain "commit" call.
496 do
498 Foo::Bar->do(
499 'insert into table (foo, bar) values (?, ?)',
500 {},
501 $foo_value,
502 $bar_value,
503 );
504 The "do" method is a direct wrapper around the equivalent DBI method,
506 but applied to the appropriate locally-provided connection or
507 transaction.
508 It takes the same parameters and has the same return values and error
510 behaviour.
511 selectall_arrayref
513 The "selectall_arrayref" method is a direct wrapper around the
514 equivalent DBI method, but applied to the appropriate locally-provided
515 connection or transaction.
516 It takes the same parameters and has the same return values and error
518 behaviour.
519 selectall_hashref
521 The "selectall_hashref" method is a direct wrapper around the
522 equivalent DBI method, but applied to the appropriate locally-provided
523 connection or transaction.
524 It takes the same parameters and has the same return values and error
526 behaviour.
527 selectcol_arrayref
529 The "selectcol_arrayref" method is a direct wrapper around the
530 equivalent DBI method, but applied to the appropriate locally-provided
531 connection or transaction.
532 It takes the same parameters and has the same return values and error
534 behaviour.
535 selectrow_array
537 The "selectrow_array" method is a direct wrapper around the equivalent
538 DBI method, but applied to the appropriate locally-provided connection
539 or transaction.
540 It takes the same parameters and has the same return values and error
542 behaviour.
543 selectrow_arrayref
545 The "selectrow_arrayref" method is a direct wrapper around the
546 equivalent DBI method, but applied to the appropriate locally-provided
547 connection or transaction.
548 It takes the same parameters and has the same return values and error
550 behaviour.
551 selectrow_hashref
553 The "selectrow_hashref" method is a direct wrapper around the
554 equivalent DBI method, but applied to the appropriate locally-provided
555 connection or transaction.
556 It takes the same parameters and has the same return values and error
558 behaviour.
559 prepare
561 The "prepare" method is a direct wrapper around the equivalent DBI
562 method, but applied to the appropriate locally-provided connection or
563 transaction
564 It takes the same parameters and has the same return values and error
566 behaviour.
567 In general though, you should try to avoid the use of your own prepared
569 statements if possible, although this is only a recommendation and by
570 no means prohibited.
571 pragma
573 # Get the user_version for the schema
574 my $version = Foo::Bar->pragma('user_version');
575 The "pragma" method provides a convenient method for fetching a pragma
577 for a datase. See the SQLite documentation for more details.
578
580 When you use ORLite, your database tables will be available as objects
581 named in a camel-cased fashion. So, if your model name is Foo::Bar...
582 use ORLite {
584 package => 'Foo::Bar',
585 file => 'data/sqlite.db',
586 };
587 ... then a table named 'user' would be accessed as "Foo::Bar::User",
589 while a table named 'user_data' would become "Foo::Bar::UserData".
590 base
592 my $namespace = Foo::Bar::User->base; # Returns 'Foo::Bar'
593 Normally you will only need to work directly with a table class, and
595 only with one ORLite package.
596 However, if for some reason you need to work with multiple ORLite
598 packages at the same time without hardcoding the root namespace all the
599 time, you can determine the root namespace from an object or table
600 class with the "base" method.
601 table
603 print Foo::Bar::UserData->table; # 'user_data'
604 While you should not need the name of table for any simple operations,
606 from time to time you may need it programatically. If you do need it,
607 you can use the "table" method to get the table name.
608 table_info
610 # List the columns in the underlying table
611 my $columns = Foo::Bar::User->table_info;
612 foreach my $c ( @$columns ) {
613 print "Column $c->{name} $c->{type}";
614 print " not null" if $c->{notnull};
615 print " default $c->{dflt_value}" if defined $c->{dflt_value};
616 print " primary key" if $c->{pk};
617 print "\n";
618 }
619 The "table_info" method is a wrapper around the SQLite "table_info"
621 pragma, and provides simplified access to the column metadata for the
622 underlying table should you need it for some advanced function that
623 needs direct access to the column list.
624 Returns a reference to an "ARRAY" containing a list of columns, where
626 each column is a reference to a "HASH" with the keys "cid",
627 "dflt_value", "name", "notnull", "pk" and "type".
628 new
630 my $user = Foo::Bar::User->new(
631 name => 'Your Name',
632 age => 23,
633 );
634 The "new" constructor creates an anonymous object, without reading or
636 writing it to the database. It also won't do validation of any kind,
637 since ORLite is designed for use with embedded databases and presumes
638 that you know what you are doing.
639 insert
641 my $user = Foo::Bar::User->new(
642 name => 'Your Name',
643 age => 23,
644 )->insert;
645 The "insert" method takes an existing anonymous object and inserts it
647 into the database, returning the object back as a convenience.
648 It provides the second half of the slower manual two-phase object
650 construction process.
651 If the table has an auto-incrementing primary key (and you have not
653 provided a value for it yourself) the identifier for the new record
654 will be fetched back from the database and set in your object.
655 my $object = Foo::Bar::User->new( name => 'Foo' )->insert;
657 print "Created new user with id " . $user->id . "\n";
659 create
661 my $user = Foo::Bar::User->create(
662 name => 'Your Name',
663 age => 23,
664 );
665 While the "new" + "insert" methods are useful when you need to do
667 interesting constructor mechanisms, for most situations you already
668 have all the attributes ready and just want to create and insert the
669 record in a single step.
670 The "create" method provides this shorthand mechanism and is just the
672 functional equivalent of the following.
673 sub create {
675 shift->new(@_)->insert;
676 }
677 It returns the newly created object after it has been inserted.
679 load
681 my $user = Foo::Bar::User->load( $id );
682 If your table has single column primary key, a "load" method will be
684 generated in the class. If there is no primary key, the method is not
685 created.
686 The "load" method provides a shortcut mechanism for fetching a single
688 object based on the value of the primary key. However it should only be
689 used for cases where your code trusts the record to already exists.
690 It returns a "Foo::Bar::User" object, or throws an exception if the
692 object does not exist.
693 id
695 The "id" accessor is a convenience method that is added to your table
696 class to increase the readability of your code when ORLite detects
697 certain patterns of column naming.
698 For example, take the following definition where convention is that all
700 primary keys are the table name followed by "_id".
701 create table foo_bar (
703 foo_bar_id integer not null primary key,
704 name string not null,
705 )
706 When ORLite detects the use of this pattern, and as long as the table
708 does not have an "id" column, the additional "id" accessor will be
709 added to your class, making these expressions equivalent both in
710 function and performance.
711 my $foo_bar = My::FooBar->create( name => 'Hello' );
713 # Column name accessor
715 $foo_bar->foo_bar_id;
716 # Convenience id accessor
718 $foo_bar->id;
719 As you can see, the latter involves much less repetition and reads much
721 more cleanly.
722 select
724 my @users = Foo::Bar::User->select;
725 my $users = Foo::Bar::User->select( 'where name = ?', @args );
727 The "select" method is used to retrieve objects from the database.
729 In list context, returns an array with all matching elements. In
731 scalar context an array reference is returned with that same data.
732 You can filter the results or order them by passing SQL code to the
734 method.
735 my @users = DB::User->select( 'where name = ?', $name );
737 my $users = DB::User->select( 'order by name' );
739 Because "select" provides only the thinnest of layers around pure SQL
741 (it merely generates the "SELECT ... FROM table_name") you are free to
742 use anything you wish in your query, including subselects and function
743 calls.
744 If called without any arguments, it will return all rows of the table
746 in the natural sort order of SQLite.
747 iterate
749 Foo::Bar::User->iterate( sub {
750 print $_->name . "\n";
751 } );
752 The "iterate" method enables the processing of large tables one record
754 at a time without loading having to them all into memory in advance.
755 This plays well to the strength of SQLite, allowing it to do the work
757 of loading arbitrarily large stream of records from disk while
758 retaining the full power of Perl when processing the records.
759 The last argument to "iterate" must be a subroutine reference that will
761 be called for each element in the list, with the object provided in the
762 topic variable $_.
763 This makes the "iterate" code fragment above functionally equivalent to
765 the following, except with an O(1) memory cost instead of O(n).
766 foreach ( Foo::Bar::User->select ) {
768 print $_->name . "\n";
769 }
770 You can filter the list via SQL in the same way you can with "select".
772 Foo::Bar::User->iterate(
774 'order by ?', 'name',
775 sub {
776 print $_->name . "\n";
777 }
778 );
779 You can also use it in raw form from the root namespace for better
781 control. Using this form also allows for the use of arbitrarily
782 complex queries, including joins. Instead of being objects, rows are
783 provided as ARRAY references when used in this form.
784 Foo::Bar->iterate(
786 'select name from user order by name',
787 sub {
788 print $_->[0] . "\n";
789 }
790 );
791 count
793 my $everyone = Foo::Bar::User->count;
794 my $young = Foo::Bar::User->count( 'where age <= ?', 13 );
796 You can count the total number of elements in a table by calling the
798 "count" method with no arguments. You can also narrow your count by
799 passing sql conditions to the method in the same manner as with the
800 "select" method.
801 delete
803 # Delete a single object from the database
804 $user->delete;
805 # Delete a range of rows from the database
807 Foo::Bar::User->delete( 'where age <= ?', 13 );
808 The "delete" method will delete the single row representing an object,
810 based on the primary key or SQLite rowid of that object.
811 The object that you delete will be left intact and untouched, and you
813 remain free to do with it whatever you wish.
814 delete_where
816 # Delete a range of rows from the database
817 Foo::Bar::User->delete( 'age <= ?', 13 );
818 The "delete_where" static method allows the delete of large numbers of
820 rows from a database while protecting against accidentally doing a
821 boundless delete (the "truncate" method is provided specifically for
822 this purpose).
823 It takes the same parameters for deleting as the "select" method, with
825 the exception that the "where" keyword is automatically provided for
826 your and should not be passed in.
827 This ensures that providing an empty of null condition results in an
829 invalid SQL query and the deletion will not occur.
830 Returns the number of rows deleted from the database (which may be
832 zero).
833 truncate
835 # Clear out all records from the table
836 Foo::Bar::User->truncate;
837 The "truncate" method takes no parameters and is used for only one
839 purpose, to completely empty a table of all rows.
840 Having a separate method from "delete" not only prevents accidents, but
842 will also do the deletion via the direct SQLite "TRUNCATE TABLE" query.
843 This uses a different deletion mechanism, and is significantly faster
844 than a plain SQL "DELETE".
845
847 - Support for intuiting reverse relations from foreign keys
848 - Document the 'create' and 'table' params
850
852 Bugs should be reported via the CPAN bug tracker at
853 <http://rt.cpan.org/NoAuth/ReportBug.html?Queue=ORLite>
855 For other issues, contact the author.
857
859 Adam Kennedy <adamk@cpan.org>
860
862 ORLite::Mirror, ORLite::Migrate, ORLite::Pod
863
865 Copyright 2008 - 2012 Adam Kennedy.
866 This program is free software; you can redistribute it and/or modify it
868 under the same terms as Perl itself.
869 The full text of the license can be found in the LICENSE file included
871 with this module.
872perl v5.28.0 2012-09-30 ORLite(3)