setup installer script in magento module - sql

Question

Hi i am developing a little magento module.
below is my directory structure of module
app/code/local/Xyz/Total
/var/www/magext/app/code/local/Xyz/Total/Block/Prototal.php
/var/www/magext/app/code/local/Xyz/Total/controllers/IndexController.php
/var/www/magext/app/code/local/Xyz/Total/etc/config.xml
/var/www/magext/app/code/local/Xyz/Total/Model/Price/Observer.php
below is my config file code
<?xml version="1.0"?>
<config>
<global>
<blocks>
<total>
<class>Xyz_Total_Block</class>
</total>
</blocks>
<models>
<xyztotal>
<class>Xyz_Total_Model</class>
</xyztotal>
</models>
<events>
<sales_order_place_after>
<observers>
<xyz_total_price_observer>
<type>singleton</type>
<class>Xyz_Total_Model_Price_Observer</class>
<method>apply_discount_percent</method>
</xyz_total_price_observer>
</observers>
</sales_order_place_after>
</events>
</global>
<frontend>
<routers>
<total>
<use>standard</use>
<args>
<module>Xyz_Total</module>
<frontName>newcatalog</frontName>
</args>
</total>
</routers>
<layout>
<updates>
<total>
<file>total.xml</file>
</total>
</updates>
</layout>
</frontend>
</config>
now what i need to install a product attribute through my module
.But i cant understand understand where should i put my installer
script and how to modify config file.
please suggest.

Answer 1

I saw your config.xml i am not able to find xml vesrion.
So you need to give xml version like below example:
<config>
<modules>
<Xyz_Total>
<version>0.1.0</version> <!-- Version of module -->
</Xyz_Total>
</modules>
</config>
Now create the file app/code/local/Xyz/Total/sql/total_setup/mysql4-install-0.1.0.ph‌​p
After that reinstall the module And check it.

Answer 2

You also have to add below code in config.xml under config tag.
<global>
<resources> <!-- These are resource setting giving access to module, read/write permission on database -->
<total_setup>
<setup>
<module>Xyz_Total</module>
</setup>
<connection>
<use>core_setup</use>
</connection>
</total_setup>
<total_write>
<connection>
<use>core_write</use>
</connection>
</total_write>
<total_read>
<connection>
<use>core_read</use>
</connection>
</total_read>
</resources>
</global>
After that reinstall module.

Answer 3

Take a look # Adding custom product attributes in Magento using setup script
<modules>
<Xyz_Total>
<version>0.1.0</version>
</Xyz_Total>
</modules>
<global>
....
<models>
<xyztotal>
<class>Xyz_Total_Model</class>
<resourceModel>total_setup</resourceModel>
</xyztotal>
</models>
<resources>
<catalog_setup>
<setup>
<module>Mage_Catalog</module>
<class>Mage_Catalog_Model_Resource_Setup</class><!-- that line !-->
</setup>
</catalog_setup>
</resources>
...
In
app/code/local/Xyz/Total/sql/total_setup/mysql4-install-0.1.0.ph‌​p
$installer->addAttribute('catalog_product', 'offer_type', array(
'backend' => '',
...
));