creating update for a custom module

Question

My question is about creating update for a custom module extension that I have made.

I have no idea where to begin. So breafly here is what my module does

• It create a database table
• Stores data from a form
• Show them backend in grid

Now the forms have to have more options. but my table dont have enough colums.

So my question is

How do i make an update for my module, that update my tables and update the output to my backend grid?

Answer 1

so you have a version in config.xml. Something like <version>1.0.0</version>.
Replace below 1.0.0 with the version you actually have and 1.0.1 with your version but with the last number incremented.

You need to create the upgrade-1.0.0-1.0.1.php in the same folder you have install-1.0.0.php

<?php 
$installer = $this;
$connection = $installer->getConnection();
//do this for each column you want to add
$connection->addColumn($installer->getTable('your table name here'), 'your_column_name_here', array(
        'type'      => Varien_Db_Ddl_Table::TYPE_TEXT, //or any other type you need
        'comment'   => 'Column name here',
    ));

Then change the version in config.xml from <version>1.0.0</version> to <version>1.0.1</version> and clear the cache.

The upgrade script will add columns to your table and you can continue your work.