Alzabo::FAQ - Frequently Asked Questions
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) and both schemas are for the same RDBMS, you can simply do this:
my @sql = $schema1->rules->schema_diff( old => $schema1, new => $schema2 );
@sql array will contain all the SQL statements necessary to transform the schema in
$schema1 into the schema in
If you want to sync a schema object to the current state of the RDBMS backend's schema, check out the
How can I make a local copy of the documentation as HTML?
Alzabo comes with a script called
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.
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 );
How can I get objects for tables linked via the Mason GUI?
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?
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
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
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
docs_as_pod() schema method after MethodMaker does its thing.
Dave Rolsky, <email@example.com>