=head1 NAME

Alzabo::FAQ - Frequently Asked Questions

=head2 How can I generate the SQL to turn one schema into another?

Assuming you have schema objects representing these already created
(through reverse engineering for example) B<and> both schemas are for
the same RDBMS, you can simply do this:

 my @sql = $schema1->rules->schema_diff( old => $schema1, new => $schema2 );

The C<@sql> array will contain all the SQL statements necessary to
transform the schema in C<$schema1> into the schema in C<$schema2>.

If you want to sync a schema object to the current state of the RDBMS
backend's schema, check out the L<C<<
Alzabo::Create::Schema->sync_backend
>>|Alzabo::Create::Schema/sync_backend> method.

=head2 How can I make a local copy of the documentation as HTML?

Alzabo comes with a script called C<make_html_docs.pl>.  It takes
three arguments.  The first is the source file directory root.  The
second is the target directory.  The last is the absolute URL path
that this target directory represents.  If you have perl 5.6.0 or
greated installed, it is recommended that you use it to run this
script as the Pod::Html module included with more recent Perls does a
much better job of making HTML.

If you were in the root of the source directory you might run this as:

 perl ./make_html_docs.pl ./lib /usr/local/apache/htdocs/Alzabo_docs /Alzabo_docs

The script will create an index.html file as well as turning the
documentation into HTML.

=head2 How can I optimize memory usage under mod_perl?

You should simply preload the Alzabo::Runtime module (which loads all
the other modules it needs).

In addition, if you are using Alzabo::MethodMaker, make sure it runs
in the parent.  This module can create a lot of methods on the fly and
each method eats up some memory.

Finally, you can preload one or more schema objects.  The easiest way
to do this is to simply pass its name to Alzabo::Runtime when you use
it, like this:

  use Alzabo::Runtime qw( schema1 schema2 );

=head2 How can I get objects for tables linked via the Mason GUI?

=over 4

For example, if I have a websites2categories table which maps a list
of categories that a given web site should display -- and uses
website_id and category_id in a 1..n relationship -- what is the
proper way to set that up in the GUI and then in my code?

=back

In the GUI, you can simply create a relationship from websites to
categories, and declare it n..n.  Alzabo will automatically create a
table called websites_categories, and you're free to change the name
to whatever you want.

Then if you use C<Alzabo::MethodMaker>, Alzabo will see that you have
a table with 2 cols, both of which are part of the PK, and that it has
1..n relationships with 2 other tables, and it will create the
appropriate methods.

You can see what methods are being created by setting the
C<ALZABO_DEBUG> environment variable to "METHODMAKER" before loading
Alzabo::MethodMaker.  It'll spit everything out to STDERR.  There's
also the generated documentation, which is available via the C<<
docs_as_pod() >> schema method after MethodMaker does its thing.

=head1 AUTHOR

Dave Rolsky, <autarch@urth.org>

=cut