[%# # IMPORTANT NOTE # This documentation is generated automatically from source # templates. Any changes you make here may be lost. # # The 'docsrc' documentation source bundle is available for download # from http://www.template-toolkit.org/docs.html and contains all # the source templates, XML files, scripts, etc., from which the # documentation for the Template Toolkit is built. -%] [% META book = 'Modules' page = 'Plugin_DBI' %] [% WRAPPER toc; INCLUDE tocitem title = 'SYNOPSIS'; INCLUDE tocitem title = 'DESCRIPTION'; INCLUDE tocitem title = 'OBJECT METHODS' subs = [ 'connect($data_source, $username, $password)', 'query($sql)', 'prepare($sql)', 'execute(@args)', 'do($sql)', 'quote($value, $type)', 'disconnect()' ]; INCLUDE tocitem title = 'PRE-REQUISITES'; INCLUDE tocitem title = 'AUTHORS'; INCLUDE tocitem title = 'VERSION'; INCLUDE tocitem title = 'HISTORY'; INCLUDE tocitem title = 'COPYRIGHT'; INCLUDE tocitem title = 'SEE ALSO'; END %] [% WRAPPER section title='SYNOPSIS' -%]

        # use positional arguments...
        [% tt_start_tag %] USE DBI('dbi:driver:database', 'username', 'password') [% tt_end_tag %]

        # ...or named parameters...
        [% tt_start_tag %] USE DBI(data_source = 'dbi:driver:database',
                   username    = 'username',
                   password    = 'password') [% tt_end_tag %]

        # ...or call connect() explicitly
        [% tt_start_tag %] USE DBI [% tt_end_tag %]
        [% tt_start_tag %] DBI.connect(dsn, user, pass) [% tt_end_tag %]

        # Or don't connect at all, and when necessary DBI will connect
        # automatically using the environment variable DBI_DSN. See below.

        [% tt_start_tag %] FOREACH item = DBI.query( 'SELECT rows FROM table' ) [% tt_end_tag %]
           Here's some row data: [% tt_start_tag %] item.field [% tt_end_tag %]
        [% tt_start_tag %] END [% tt_end_tag %]

        [% tt_start_tag %] query = DBI.prepare('SELECT * FROM user WHERE manager = ?') [% tt_end_tag %]
        [% tt_start_tag %] FOREACH user = query.execute('sam') [% tt_end_tag %]
           ...
        [% tt_start_tag %] FOREACH user = query.execute('abw') [% tt_end_tag %]
           ...

        [% tt_start_tag %] IF DBI.do("DELETE FROM users WHERE uid = 'sam'") [% tt_end_tag %]
           Oh No!  The user was deleted!
        [% tt_start_tag %] END [% tt_end_tag %]

[%- END %] [% WRAPPER section title='DESCRIPTION' -%]

This Template Toolkit plugin module provides an interface to the Perl DBI/DBD modules, allowing you to integrate SQL queries into your template documents.

A DBI plugin object can be created as follows:

        [% tt_start_tag %] USE DBI [% tt_end_tag %]

This creates an uninitialised DBI object. You can then open a connection to a database using the connect() method.

        [% tt_start_tag %] DBI.connect('dbi:driver:database', 'username', 'password') [% tt_end_tag %]

The DBI connection can be opened when the plugin is created by passing arguments to the constructor, called from the USE directive.

        [% tt_start_tag %] USE DBI('dbi:driver:database', 'username', 'password') [% tt_end_tag %]

You can also use named parameters to provide the data source connection string, user name and password.

        [% tt_start_tag %] USE DBI(data_source => 'dbi:driver:database',
                   username    => 'username',
                   password    => 'password')  [% tt_end_tag %]

Lazy Template hackers may prefer to use 'dsn' or 'connect' as a shorthand form of the 'data_source' parameter, and 'user' and 'pass' as shorthand forms of 'username' and 'password', respectively.

        [% tt_start_tag %] USE DBI(connect => 'dbi:driver:database',
                   user    => 'username',
                   pass    => 'password')  [% tt_end_tag %]

Any additional DBI attributes can be specified as named parameters. The 'PrintError' attribute defaults to 0 unless explicitly set true.

        [% tt_start_tag %] USE DBI(dsn, user, pass, ChopBlanks=1) [% tt_end_tag %]

The DBI connect_cached() method is used instead of the connect() method. This allows for connection caching in a server environment, such as when the Template Toolkit is used from an Apache mod_perl handler. In such a case, simply enable the mod_env module and put in a line such as:

SetEnv DBI_DSN "dbi:DBDriver:DBName;host=DBHost;user=User;password=Password"

Then use the DBI plugin without any parameters and without calling connect.

Methods can then be called on the plugin object using the familiar dotted notation:

        [% tt_start_tag %] FOREACH item = DBI.query( 'SELECT rows FROM table' ) [% tt_end_tag %]
           Here's some row data: [% tt_start_tag %] item.field [% tt_end_tag %]
        [% tt_start_tag %] END [% tt_end_tag %]

See [% ttlink('OBJECT METHODS') -%] below for further details of the methods available.

An alternate variable name can be provided for the plugin as per regular Template Toolkit syntax:

        [% tt_start_tag %] USE mydb = DBI('dbi:driver:database','username','password') [% tt_end_tag %]

        [% tt_start_tag %] FOREACH item = mydb.query( 'SELECT rows FROM table' ) [% tt_end_tag %]
           ...

You can also specify the DBI plugin name in lower case if you prefer:

        [% tt_start_tag %] USE dbi(dsn, user, pass) [% tt_end_tag %]
        [% tt_start_tag %] FOREACH item = dbi.query( 'SELECT rows FROM table' ) [% tt_end_tag %]
           ...

The disconnect() method can be called to explicitly disconnect the current database, but this generally shouldn't be necessary as it is called automatically when the plugin goes out of scope. You can call connect() at any time to open a connection to another database. The previous connection will be closed automatically.

[%- END %] [% WRAPPER section title='OBJECT METHODS' -%][% WRAPPER subsection title = 'connect($data_source, $username, $password)' -%]

Establishes a database connection. This method accepts both positional and named parameter syntax. e.g.

        [% tt_start_tag %] DBI.connect(data_source, username, password) [% tt_end_tag %]
        [% tt_start_tag %] DBI.connect(data_source = 'dbi:driver:database'
                       username    = 'foo'
                       password    = 'bar' ) [% tt_end_tag %]

The connect method allows you to connect to a data source explicitly. It can also be used to reconnect an exisiting object to a different data source.

[%- END %] [% WRAPPER subsection title = 'query($sql)' -%]

This method submits an SQL query to the database and creates an iterator object to return the results. This may be used directly in a FOREACH directive as shown below. Data is automatically fetched a row at a time from the query result set as required for memory efficiency.

        [% tt_start_tag %] FOREACH row = DBI.query('select * from users') [% tt_end_tag %]
           Each [% tt_start_tag %] row.whatever [% tt_end_tag %] can be processed here
        [% tt_start_tag %] END [% tt_end_tag %]

[%- END %] [% WRAPPER subsection title = 'prepare($sql)' -%]

Prepare a query for later execution. This returns a compiled query object (of the Template::Plugin::DBI::Query class) on which the execute() method can subsequently be called.

        [% tt_start_tag %] query = DBI.prepare('SELECT * FROM users WHERE id = ?') [% tt_end_tag %]

[%- END %] [% WRAPPER subsection title = 'execute(@args)' -%]

Execute a previously prepared query. This method should be called on the query object returned by the prepare() method. Returns an iterator object which can be used directly in a FOREACH directive.

        [% tt_start_tag %] query = DBI.prepare('SELECT * FROM users WHERE manager = ?') [% tt_end_tag %]

        [% tt_start_tag %] FOREACH user = query.execute('sam') [% tt_end_tag %]
           [% tt_start_tag %] user.name [% tt_end_tag %]
        [% tt_start_tag %] END [% tt_end_tag %]

        [% tt_start_tag %] FOREACH user = query.execute('sam') [% tt_end_tag %]
           [% tt_start_tag %] user.name [% tt_end_tag %]
        [% tt_start_tag %] END [% tt_end_tag %]

[%- END %] [% WRAPPER subsection title = 'do($sql)' -%]

The do() method executes a sql statement from which no records are returned. It will return true if the statement was successful

        [% tt_start_tag %] IF DBI.do("DELETE FROM users WHERE uid = 'sam'") [% tt_end_tag %]
           The user was successfully deleted.
        [% tt_start_tag %] END [% tt_end_tag %]

[%- END %] [% WRAPPER subsection title = 'quote($value, $type)' -%]

Calls the quote() method on the underlying DBI handle to quote the value specified in the appropriate manner for its type.

[%- END %] [% WRAPPER subsection title = 'disconnect()' -%]

Disconnects the current database.

[%- END %] [%- END %] [% WRAPPER section title='PRE-REQUISITES' -%]

Perl 5.005, Template-Toolkit 2.00, DBI 1.02

[%- END %] [% WRAPPER section title='AUTHORS' -%]

The DBI plugin was written by Simon A Matthews, <sam@knowledgepool.com>, with contributions from Andy Wardley <abw@kfs.org>.

[%- END %] [% WRAPPER section title='VERSION' -%]

1.04, distributed as part of the Template Toolkit version 2.06, released on 07 November 2001.

[%- END %] [% WRAPPER section title='HISTORY' -%]

- 1.04 2001/04/06 abw

  Removed duplicated $VERSION number.

- 1.03 2000/11/31 sam

  Added _connect method to Plugin::DBI for backwards compatability with code from version 1 of Template that subclassed the plugin

  Changed the new method on the DBI plugin so that it checks to see if it is being called by a subclassed object.

  Fixed the return value in the DBI plugin when connect is called more than once in the lifetime of the plugin.

- 1.02 2000/11/14 abw

  Added prev() and next() methods to Template::Plugin::DBI:Iterator to return the previous and next items in the iteration set or undef if not available.

- 1.01 2000/11/03 abw

  Modified connect method to pass all named arguments to DBI. e.g.

          [% tt_start_tag %] USE DBI(dsn, user, pass, ChopBlanks=1) [% tt_end_tag %]

[%- END %] [% WRAPPER section title='COPYRIGHT' -%]

Copyright (C) 1999-2000 Simon Matthews. All Rights Reserved

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

[%- END %] [% WRAPPER section title='SEE ALSO' -%]

[% ttlink('Template::Plugin', 'Template::Plugin') -%], [% ttlink('CPAN::DBI', 'CPAN::DBI') -%]

[%- END %]