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diff --git a/Master/tlpkg/tlperl0/lib/DBIx/Simple/Examples.pod b/Master/tlpkg/tlperl0/lib/DBIx/Simple/Examples.pod new file mode 100755 index 00000000000..dafe78e8d27 --- /dev/null +++ b/Master/tlpkg/tlperl0/lib/DBIx/Simple/Examples.pod @@ -0,0 +1,390 @@ +=head1 NAME + +DBIx::Simple::Examples - Examples of how to use DBIx::Simple + +=head1 DESCRIPTION + +DBIx::Simple provides a simplified interface to DBI, Perl's powerful database +module. + +=head1 EXAMPLES + +=head2 General + + #!/usr/bin/perl -w + use strict; + use DBIx::Simple; + + # Instant database with DBD::SQLite + my $db = DBIx::Simple->connect('dbi:SQLite:dbname=file.dat') + or die DBIx::Simple->error; + + # Connecting to a MySQL database + my $db = DBIx::Simple->connect( + 'DBI:mysql:database=test', # DBI source specification + 'test', 'test', # Username and password + { RaiseError => 1 } # Additional options + ); + + # Using an existing database handle + my $db = DBIx::Simple->connect($dbh); + + # Abstracted example: $db->query($query, @variables)->what_you_want; + + $db->commit or die $db->error; + +=head2 Simple Queries + + $db->query('DELETE FROM foo WHERE id = ?', $id) or die $db->error; + + for (1..100) { + $db->query( + 'INSERT INTO randomvalues VALUES (?, ?)', + int rand(10), + int rand(10) + ) or die $db->error; + } + + $db->query( + 'INSERT INTO sometable VALUES (??)', + $first, $second, $third, $fourth, $fifth, $sixth + ); + # (??) is expanded to (?, ?, ?, ?, ?, ?) automatically + +=head2 Single row queries + + my ($two) = $db->query('SELECT 1 + 1')->list; + my ($three, $four) = $db->query('SELECT 3, 2 + 2')->list; + + my ($name, $email) = $db->query( + 'SELECT name, email FROM people WHERE email = ? LIMIT 1', + $mail + )->list; + +Or, more efficiently: + + $db->query('SELECT 1 + 1')->into(my $two); + $db->query('SELECT 3, 2 + 2')->into(my ($three, $four)); + + $db->query( + 'SELECT name, email FROM people WHERE email = ? LIMIT 1', + $mail + )->into(my ($name, $email)); + +=head2 Fetching all rows in one go + +=head3 One big flattened list (primarily for single column queries) + + my @names = $db->query('SELECT name FROM people WHERE id > 5')->flat; + +=head3 Rows as array references + + for my $row ($db->query('SELECT name, email FROM people')->arrays) { + print "Name: $row->[0], Email: $row->[1]\n"; + } + +=head3 Rows as hash references + + for my $row ($db->query('SELECT name, email FROM people')->hashes) { + print "Name: $row->{name}, Email: $row->{email}\n"; + } + +=head2 Fetching one row at a time + +=head3 Rows into separate variables + + { + my $result = $db->query('SELECT name, email FROM people'); + $result->bind(my ($name, $email)); + while ($result->fetch) { + print "Name: $name, Email: $email\n"; + } + } + +or: + + { + my $result = $db->query('SELECT name, email FROM people'); + while ($result->into(my ($name, $email))) { + print "Name: $name, Email: $email\n"; + } + } + +=head3 Rows as lists + + { + my $result = $db->query('SELECT name, email FROM people'); + while (my @row = $result->list) { + print "Name: $row[0], Email: $row[1]\n"; + } + } + +=head3 Rows as array references + + { + my $result = $db->query('SELECT name, email FROM people'); + while (my $row = $result->array) { + print "Name: $row->[0], Email: $row->[1]\n"; + } + } + +=head3 Rows as hash references + + { + my $result = $db->query('SELECT name, email FROM people'); + while (my $row = $result->hash) { + print "Name: $row->{name}, Email: $row->{email}\n"; + } + } + +=head2 Building maps (also fetching all rows in one go) + +=head3 A hash of hashes + + my $customers = + $db + -> query('SELECT id, name, location FROM people') + -> map_hashes('id'); + + # $customers = { $id => { name => $name, location => $location } } + +=head3 A hash of arrays + + my $customers = + $db + -> query('SELECT id, name, location FROM people') + -> map_arrays(0); + + # $customers = { $id => [ $name, $location ] } + +=head3 A hash of values (two-column queries) + + my $names = + $db + -> query('SELECT id, name FROM people') + -> map; + + # $names = { $id => $name } + +=head1 EXAMPLES WITH SQL::Interp + +If you have SQL::Interp installed, you can use the semi-abstracting method +C<iquery>. This works just like C<query>, but with parts of the query +interleaved with the bind arguments, passed as references. + +You should read L<SQL::Interp>. These examples are not enough to fully +understand all the possibilities. + +The following examples are based on the documentation of SQL::Interp. + + my $result = $db->iquery('INSERT INTO table', \%item); + my $result = $db->iquery('UPDATE table SET', \%item, 'WHERE y <> ', \2); + my $result = $db->iquery('DELETE FROM table WHERE y = ', \2); + + # These two select syntax produce the same result + my $result = $db->iquery('SELECT * FROM table WHERE x = ', \$s, 'AND y IN', \@v); + my $result = $db->iquery('SELECT * FROM table WHERE', {x => $s, y => \@v}); + + for ($result->hashes) { ... } + +Use a syntax highlighting editor for good visual distinction. + +If you need the helper functions C<sql> and C<sql_type>, you can import them +with C<use SQL::Interp;> + +=head1 EXAMPLES WITH SQL::Abstract + +If you have SQL::Abstract installed, you can use the abstracting methods +C<select>, C<insert>, C<update>, C<delete>. These work like C<query>, but +instead of a query and bind arguments, use abstracted arguments. + +You should read L<SQL::Abstract>. These examples are not enough to fully +understand all the possibilities. + +The SQL::Abstract object is available (writable) through the C<abstract> +property. + +The following examples are based on the documentation of SQL::Abstract. + +=head2 Overview + +If you don't like the defaults, just assign a new object: + + $db->abstract = SQL::Abstract->new( + case => 'lower', + cmp => 'like', + logic => 'and', + convert => 'upper' + ); + +If you don't assign any object, one will be created automatically using the +default options. The SQL::Abstract module is loaded on demand. + + my $result = $db->select($table, \@fields, \%where, \@order); + my $result = $db->insert($table, \%fieldvals || \@values); + my $result = $db->update($table, \%fieldvals, \%where); + my $result = $db->delete($table, \%where); + + for ($result->hashes) { ... } + +=head2 Complete examples + +=head3 select + + my @tickets = $db->select( + 'tickets', '*', { + requestor => 'inna', + worker => ['nwiger', 'rcwe', 'sfz'], + status => { '!=', 'completed' } + } + )->hashes; + +=head3 insert + +If you already have your data as a hash, inserting becomes much easier: + + $db->insert('people', \%data); + +Instead of: + + $db->query( + q[ + INSERT + INTO people (name, phone, address, ...) + VALUES (??) + ], + @data{'name', 'phone', 'address', ... } + ); + +=head3 update, delete + + $db->update( + 'tickets', { + worker => 'juerd', + status => 'completed' + }, + { id => $id } + ) + + $db->delete('tickets', { id => $id }); + +=head3 where + +The C<where> method is not wrapped directly, because it doesn't generate a +query and thus doesn't really have anything to do with the database module. + +But using the C<abstract> property, you can still easily access it: + + my $where = $db->abstract->where({ foo => $foo }); + +=head1 EXAMPLES WITH DBIx::XHTML_Table + +If you have DBIx::XHTML_Table installed, you can use the result methods +C<xto> and C<html>. + +You should read L<DBIx::XHTML_Table>. These examples are not enough to fully +understand what is going on. When reading that documentation, note that you +don't have to pass hash references to DBIx::Simple's methods. It is supported, +though. + +DBIx::XHTML_Table is loaded on demand. + +=head2 Overview + +To print a simple table, all you have to do is: + + print $db->query('SELECT * FROM foo')->html; + +Of course, anything that produces a result object can be used. The same thing +using the abstraction method C<select> would be: + + print $db->select('foo', '*')->html; + +A DBIx::XHTML_Table object can be generated with the C<xto> (B<X>HTML_B<T>able +B<O>bject) method: + + my $table = $db->query($query)->xto; + +=head2 Passing attributes + +DBIx::Simple sends the attributes you pass to C<html> both to the constructor +and the output method. This allows you to specify both HTML attributes (like +C<bgcolor>) and options for XHTML_Table (like C<no_ucfirst> and C<no_indent>) +all at once: + + print $result->html( + tr => { bgcolor => [ qw/silver white/ ] }, + no_ucfirst => 1 + ); + +=head2 Using an XHTML_Table object + +Not everything can be controlled by passing attributes. For full flexibility, +the XHTML_Table object can be used directly: + + my $table = $db->query($query)->xto( + tr => { bgcolor => [ qw/silver white/ ] } + ); + + $table->set_group('client', 1); + $table->calc_totals('credit', '%.2f'); + + print $table->output({ no_ucfirst => 1 }); # note the {}! + +=head1 EXAMPLES WITH Text::Table + +=over 8 + +=item C<< $result->text("neat") >> + +Neither neat nor pretty, but useful for debugging. Uses DBI's C<neat_list> +method. Doesn't display column names. + + '1', 'Camel', 'mammal' + '2', 'Llama', 'mammal' + '3', 'Owl', 'bird' + '4', 'Juerd', undef + +=item C<< $result->text("table") >> + +Displays a simple table using ASCII lines. + + id | animal | type + ---+--------+------- + 1 | Camel | mammal + 2 | Llama | mammal + 3 | Owl | bird + 4 | Juerd | + +=item C<< $result->text("box") >> + +Displays a simple table using ASCII lines, with an outside border. + + +----+--------+--------+ + | id | animal | type | + +----+--------+--------+ + | 1 | Camel | mammal | + | 2 | Llama | mammal | + | 3 | Owl | bird | + | 4 | Juerd | | + +----+--------+--------+ + +=back + +For C<table> and C<box>, you need Anno Siegel's Text::Table module installed. + +=head1 LICENSE + +There is no license. This software was released into the public domain. Do with +it what you want, but on your own risk. The author disclaims any +responsibility. + +=head1 AUTHOR + +Juerd Waalboer <juerd@cpan.org> <http://juerd.nl/> + +=head1 SEE ALSO + +L<DBIx::Simple>, L<SQL::Abstract> + +=cut |