Custom module not saving to Database

Question

I have created a custom module using the atwix tutorial: http://www.atwix.com/magento/adding-custom-attribute-to-a-cms-page/

but I cannot save the data entered into the custom module from the cms into the database. I flushed the cache because I read that can help but it doesn't make a difference.

I also checked my database in phpmyadmin and can see that the query isn't being executed. I think the main reason for this is because I am having problems creating my own installer script. I saw the tutorial on the Magento website but it didn't work even though I followed it. I don't understand what I'm doing wrong and after pulling my hair out for 3 days I need help.

I have attached a screenshot of my files and the file structure:

Here is the code from my config.xl file:

<?xml version="1.0"?>
<config>
    <modules>
        <Aa_Custom>
            <version>0.1.0</version>
        </Aa_Custom>
    </modules>
    <global>
        <models>
            <aacustom>
                <class>Aa_Custom_Model</class>
            </aacustom>
        </models>
        <events>
            <adminhtml_cms_page_edit_tab_content_prepare_form>
                <observers>
                    <aa_page_edit_tab_content>
                        <type>singleton</type>
                        <class>Aa_Custom_Model_Observer</class>
                        <method>cmsField</method>
                    </aa_page_edit_tab_content>
                </observers>
            </adminhtml_cms_page_edit_tab_content_prepare_form>
        </events>
        <page>
            <layouts>
                <aa_custom_page>
                    <label>Aa Custom Page</label>
                    <template>page/aa-page.phtml</template>
                </aa_custom_page>
            </layouts>
        </page>
    </global>
</config>

Answer 1

The setup script is not running because you have not defined this resource in your config.xml. You need to include:

...
<global>
    ...
    <resources>
        <custom_setup>
            <setup>
                <module>Aa_Custom</module>
                <class>Mage_Catalog_Model_Resource_Setup</class> <!-- depending on setup script content this may not be needed -->
            </setup>
        </custom_setup>
    </resources>
</global>
...

The node <custom_setup> defines the location the script should reside under the sql directory, so in this example you need to put your script in a custom_setup subdirectory of the sql directory. As a side note depending on Magento version (1.6CE onwards) you may also want to switch to the new style setup script which is just named install-0.1.0.php.