1Padre::DB::Session(3) User Contributed Perl DocumentationPadre::DB::Session(3)
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NAME

6       Padre::DB::Session - Padre::DB class for the session table
7

SYNOPSIS

9         my @sessions = Padre::DB::Session->select;
10

DESCRIPTION

12       This class allows storing in Padre's database the session that Padre
13       knows.  This is useful in order to quickly restore a given set of
14       files.
15
16       This is the primary table, you also need to check
17       "Padre::DB::SessionFiles".
18

METHODS

20   last_padre_session
21         my $session = last_padre_session()
22
23       Return a "Padre::DB::Session" object pointing to last Padre session. If
24       none exists, a new one will be created and returned.
25
26   files
27         my @files = $session->files
28
29       Return a list of files ("Padre::DB::SessionFile" objects) referenced by
30       current $session.
31
32   base
33         # Returns 'Padre::DB'
34         my $namespace = Padre::DB::Session->base;
35
36       Normally you will only need to work directly with a table class, and
37       only with one ORLite package.
38
39       However, if for some reason you need to work with multiple ORLite
40       packages at the same time without hardcoding the root namespace all the
41       time, you can determine the root namespace from an object or table
42       class with the "base" method.
43
44   table
45         # Returns 'session'
46         print Padre::DB::Session->table;
47
48       While you should not need the name of table for any simple operations,
49       from time to time you may need it programatically. If you do need it,
50       you can use the "table" method to get the table name.
51
52   load
53         my $object = Padre::DB::Session->load( $id );
54
55       If your table has single column primary key, a "load" method will be
56       generated in the class. If there is no primary key, the method is not
57       created.
58
59       The "load" method provides a shortcut mechanism for fetching a single
60       object based on the value of the primary key. However it should only be
61       used for cases where your code trusts the record to already exists.
62
63       It returns a "Padre::DB::Session" object, or throws an exception if the
64       object does not exist.
65
66   select
67         # Get all objects in list context
68         my @list = Padre::DB::Session->select;
69
70         # Get a subset of objects in scalar context
71         my $array_ref = Padre::DB::Session->select(
72             'where id > ? order by id',
73             1000,
74         );
75
76       The "select" method executes a typical SQL "SELECT" query on the
77       session table.
78
79       It takes an optional argument of a SQL phrase to be added after the
80       "FROM session" section of the query, followed by variables to be bound
81       to the placeholders in the SQL phrase. Any SQL that is compatible with
82       SQLite can be used in the parameter.
83
84       Returns a list of Padre::DB::Session objects when called in list
85       context, or a reference to an "ARRAY" of Padre::DB::Session objects
86       when called in scalar context.
87
88       Throws an exception on error, typically directly from the DBI layer.
89
90   iterate
91         Padre::DB::Session->iterate( sub {
92             print $_->id . "\n";
93         } );
94
95       The "iterate" method enables the processing of large tables one record
96       at a time without loading having to them all into memory in advance.
97
98       This plays well to the strength of SQLite, allowing it to do the work
99       of loading arbitrarily large stream of records from disk while
100       retaining the full power of Perl when processing the records.
101
102       The last argument to "iterate" must be a subroutine reference that will
103       be called for each element in the list, with the object provided in the
104       topic variable $_.
105
106       This makes the "iterate" code fragment above functionally equivalent to
107       the following, except with an O(1) memory cost instead of O(n).
108
109         foreach ( Padre::DB::Session->select ) {
110             print $_->id . "\n";
111         }
112
113       You can filter the list via SQL in the same way you can with "select".
114
115         Padre::DB::Session->iterate(
116             'order by ?', 'id',
117             sub {
118                 print $_->id . "\n";
119             }
120         );
121
122       You can also use it in raw form from the root namespace for better
123       control.  Using this form also allows for the use of arbitrarily
124       complex queries, including joins. Instead of being objects, rows are
125       provided as "ARRAY" references when used in this form.
126
127         Padre::DB->iterate(
128             'select name from session order by id',
129             sub {
130                 print $_->[0] . "\n";
131             }
132         );
133
134   count
135         # How many objects are in the table
136         my $rows = Padre::DB::Session->count;
137
138         # How many objects
139         my $small = Padre::DB::Session->count(
140             'where id > ?',
141             1000,
142         );
143
144       The "count" method executes a "SELECT COUNT(*)" query on the session
145       table.
146
147       It takes an optional argument of a SQL phrase to be added after the
148       "FROM session" section of the query, followed by variables to be bound
149       to the placeholders in the SQL phrase. Any SQL that is compatible with
150       SQLite can be used in the parameter.
151
152       Returns the number of objects that match the condition.
153
154       Throws an exception on error, typically directly from the DBI layer.
155
156   new
157         TO BE COMPLETED
158
159       The "new" constructor is used to create a new abstract object that is
160       not (yet) written to the database.
161
162       Returns a new Padre::DB::Session object.
163
164   create
165         my $object = Padre::DB::Session->create(
166
167             id => 'value',
168
169             name => 'value',
170
171             description => 'value',
172
173             last_update => 'value',
174
175         );
176
177       The "create" constructor is a one-step combination of "new" and
178       "insert" that takes the column parameters, creates a new
179       Padre::DB::Session object, inserts the appropriate row into the session
180       table, and then returns the object.
181
182       If the primary key column "id" is not provided to the constructor (or
183       it is false) the object returned will have "id" set to the new unique
184       identifier.
185
186       Returns a new session object, or throws an exception on error,
187       typically from the DBI layer.
188
189   insert
190         $object->insert;
191
192       The "insert" method commits a new object (created with the "new"
193       method) into the database.
194
195       If a the primary key column "id" is not provided to the constructor (or
196       it is false) the object returned will have "id" set to the new unique
197       identifier.
198
199       Returns the object itself as a convenience, or throws an exception on
200       error, typically from the DBI layer.
201
202   delete
203         # Delete a single instantiated object
204         $object->delete;
205
206         # Delete multiple rows from the session table
207         Padre::DB::Session->delete('where id > ?', 1000);
208
209       The "delete" method can be used in a class form and an instance form.
210
211       When used on an existing Padre::DB::Session instance, the "delete"
212       method removes that specific instance from the "session", leaving the
213       object intact for you to deal with post-delete actions as you wish.
214
215       When used as a class method, it takes a compulsory argument of a SQL
216       phrase to be added after the "DELETE FROM session" section of the
217       query, followed by variables to be bound to the placeholders in the SQL
218       phrase. Any SQL that is compatible with SQLite can be used in the
219       parameter.
220
221       Returns true on success or throws an exception on error, or if you
222       attempt to call delete without a SQL condition phrase.
223
224   truncate
225         # Delete all records in the session table
226         Padre::DB::Session->truncate;
227
228       To prevent the common and extremely dangerous error case where deletion
229       is called accidentally without providing a condition, the use of the
230       "delete" method without a specific condition is forbidden.
231
232       Instead, the distinct method "truncate" is provided to delete all
233       records in a table with specific intent.
234
235       Returns true, or throws an exception on error.
236

ACCESSORS

238   id
239         if ( $object->id ) {
240             print "Object has been inserted\n";
241         } else {
242             print "Object has not been inserted\n";
243         }
244
245       Returns true, or throws an exception on error.
246
247       REMAINING ACCESSORS TO BE COMPLETED
248

SQL

250       The session table was originally created with the following SQL
251       command.
252
253         CREATE TABLE session (
254             id INTEGER NOT NULL PRIMARY KEY,
255             name VARCHAR(255) UNIQUE NOT NULL,
256             description VARCHAR(255),
257             last_update DATE
258         )
259

SUPPORT

261       Padre::DB::Session is part of the Padre::DB API.
262
263       See the documentation for Padre::DB for more information.
264

AUTHOR

266       Adam Kennedy <adamk@cpan.org>
267
269       Copyright 2008-2011 The Padre development team as listed in Padre.pm.
270
271       This program is free software; you can redistribute it and/or modify it
272       under the same terms as Perl itself.
273
274       The full text of the license can be found in the LICENSE file included
275       with this module.
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279perl v5.30.1                      2020-01-30             Padre::DB::Session(3)
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