=head2 Predefined searches
-You can write your own L<DBIx::Class::ResultSet> class by inheriting from it
-and defining often used searches as methods:
+You can define frequently used searches as methods by subclassing
+L<DBIx::Class::ResultSet>:
package My::DBIC::ResultSet::CD;
use strict;
you create an index on the return value of the function in question.) However,
it can be accomplished with C<DBIx::Class> when necessary.
+Your approach for doing so will depend on whether you have turned
+quoting on via the C<quote_char> and C<name_sep> attributes. If you
+explicitly defined C<quote_char> and C<name_sep> in your
+C<connect_info> (see L<DBIx::Class::Storage::DBI/"connect_info">) then
+you are using quoting, otherwise not.
+
If you do not have quoting on, simply include the function in your search
specification as you would any column:
arrayrefs together with the column name, like this: C<< [column_name => value]
>>.
+=head2 Using Unicode
+
+When using unicode character data there are two alternatives -
+either your database supports unicode characters (including setting
+the utf8 flag on the returned string), or you need to encode/decode
+data appropriately each time a string field is inserted into or
+retrieved from the database. It is better to avoid
+encoding/decoding data and to use your database's own unicode
+capabilities if at all possible.
+
+The L<DBIx::Class::UTF8Columns> component handles storing selected
+unicode columns in a database that does not directly support
+unicode. If used with a database that does correctly handle unicode
+then strange and unexpected data corrupt B<will> occur.
+
+The Catalyst Wiki Unicode page at
+L<http://wiki.catalystframework.org/wiki/tutorialsandhowtos/using_unicode>
+has additional information on the use of Unicode with Catalyst and
+DBIx::Class.
+
+The following databases do correctly handle unicode data:-
+
+=head3 MySQL
+
+MySQL supports unicode, and will correctly flag utf8 data from the
+database if the C<mysql_enable_utf8> is set in the connect options.
+
+ my $schema = My::Schema->connection('dbi:mysql:dbname=test',
+ $user, $pass,
+ { mysql_enable_utf8 => 1} );
+
+
+When set, a data retrieved from a textual column type (char,
+varchar, etc) will have the UTF-8 flag turned on if necessary. This
+enables character semantics on that string. You will also need to
+ensure that your database / table / column is configured to use
+UTF8. See Chapter 10 of the mysql manual for details.
+
+See L<DBD::mysql> for further details.
+
+=head3 Oracle
+
+Information about Oracle support for unicode can be found in
+L<DBD::Oracle/Unicode>.
+
+=head3 PostgreSQL
+
+PostgreSQL supports unicode if the character set is correctly set
+at database creation time. Additionally the C<pg_enable_utf8>
+should be set to ensure unicode data is correctly marked.
+
+ my $schema = My::Schema->connection('dbi:Pg:dbname=test',
+ $user, $pass,
+ { pg_enable_utf8 => 1} );
+
+Further information can be found in L<DBD::Pg>.
+
+=head3 SQLite
+
+SQLite version 3 and above natively use unicode internally. To
+correctly mark unicode strings taken from the database, the
+C<sqlite_unicode> flag should be set at connect time (in versions
+of L<DBD::SQLite> prior to 1.27 this attribute was named
+C<unicode>).
+
+ my $schema = My::Schema->connection('dbi:SQLite:/tmp/test.db',
+ '', '',
+ { sqlite_unicode => 1} );
+
=head1 BOOTSTRAPPING/MIGRATING
=head2 Easy migration from class-based to schema-based setup
statement and dig down to see if certain parameters cause aberrant behavior.
You might want to check out L<DBIx::Class::QueryLog> as well.
+=head1 IMPROVING PERFORMANCE
+
+=over
+
+=item *
+
+Install L<Class::XSAccessor> to speed up L<Class::Accessor::Grouped>.
+
+=item *
+
+On Perl 5.8 install L<Class::C3::XS>.
+
+=item *
+
+L<prefetch|DBIx::Class::ResultSet/prefetch> relationships, where possible. See
+L</Using joins and prefetch>.
+
+=item *
+
+Use L<populate|DBIx::Class::ResultSet/populate> in void context to insert data
+when you don't need the resulting L<DBIx::Class::Row> objects, if possible, but
+see the caveats.
+
+When inserting many rows, for best results, populate a large number of rows at a
+time, but not so large that the table is locked for an unacceptably long time.
+
+If using L<create|DBIx::Class::ResultSet/create> instead, use a transaction and
+commit every C<X> rows; where C<X> gives you the best performance without
+locking the table for too long.
+
+=item *
+
+When selecting many rows, if you don't need full-blown L<DBIx::Class::Row>
+objects, consider using L<DBIx::Class::ResultClass::HashRefInflator>.
+
+=item *
+
+See also L</STARTUP SPEED> and L</MEMORY USAGE> in this document.
+
+=back
+
=head1 STARTUP SPEED
L<DBIx::Class|DBIx::Class> programs can have a significant startup delay
projects / dbsrgits/DBIx-Class.git / blobdiff