Hello, On 11/05/2002 11:21 PM, Leif K-Brooks wrote:
I'm working on a new site, and I'm wondering whether to use an abstraction layer or not. I don't have any plans to switch DB system, but you never know what the future holds. I figure that there's no reason not to, but are there any down sides? Which abstraction layers are good?There is another point on using abstraction layers which is the fact that since many people use the same API, all can share the eventual tools and components based on that API.
For instance, I am developing a data persistence layer generator that is able to generate code and database schemas from a description in XML of the structure of a set of classes and the relationships that exist between them.
The generator creates the modelled classes and a database schema to provide persistent storage for the classes objects. The classes provide an API to retrieve and store the objects according to your application as described in the model description in XML. See below for a simple example.
With this tool you no longer need to put up with the tedious work of setting databases, write SQL by hand, write code to retrieve and store the data, etc.. This way you can speedup the development of your application often by more than an order of magnitude.
The generated code and database schema description (also in XML) is based on Metabase database abstraction, so anybody using Metabase can benefit from this tool.
Read more about this here:
http://www.meta-language.net/news-2002-11-01-persistence.html
http://www.phpclasses.org/metabase
--
Regards,
Manuel Lemos
<?xml version="1.0" encoding="iso-8859-1"?>
<!--
@(#) $Id: cms.component,v 1.3 2002/11/06 01:52:52 mlemos Exp $
-->
<component>
<name>cms</name>
<description>Content management system component</description>
<class>
<name>article</name>
<variable>
<name>title</name>
<type>text</type>
</variable>
<variable>
<name>lead</name>
<type>text</type>
</variable>
<variable>
<name>body</name>
<type>text</type>
</variable>
<variable>
<name>author</name>
<class>author</class>
</variable>
<variable>
<name>creation_date</name>
<type>timestamp</type>
</variable>
<collection>
<name>categories</name>
<class>category</class>
<reference>articles</reference>
</collection>
</class>
<class>
<name>author</name>
<variable>
<name>name</name>
<type>text</type>
</variable>
<collection>
<name>articles</name>
<class>article</class>
<reference>author</reference>
</collection>
</class>
<class>
<name>category</name>
<variable>
<name>name</name>
<type>text</type>
</variable>
<variable>
<name>description</name>
<type>text</type>
</variable>
<variable>
<name>parent</name>
<class>category</class>
</variable>
<collection>
<name>children</name>
<class>category</class>
<reference>parent</reference>
</collection>
<collection>
<name>articles</name>
<class>article</class>
<reference>categories</reference>
</collection>
</class>
<schema>
<function>
<name>installschema</name>
<type>installschema</type>
</function>
</schema>
<factory>
<function>
<name>getarticle</name>
<type>getobject</type>
<parameters>
<class>article</class>
<id>
<argument>article</argument>
</id>
</parameters>
</function>
<function>
<name>getauthor</name>
<type>getobject</type>
<parameters>
<class>author</class>
<id>
<argument>author</argument>
</id>
</parameters>
</function>
<function>
<name>getcategory</name>
<type>getobject</type>
<parameters>
<class>category</class>
<id>
<argument>category</argument>
</id>
</parameters>
</function>
</factory>
</component>
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