How to create a table through one-to-many magento ORM?

Question

MySQL

How to create a table through one-to-many magento ORM? There is a Promotion and 100-1000000 products can be tied to it. Shares table added next. thus:
$installer = $this;
$table = $installer->getTable('webpromotions/promotions');
$installer->startSetup();
$installer->getConnection()->dropTable($table);
$tablePromotions = $installer->getConnection()
->newTable($table)
->addColumn('id', Varien_Db_Ddl_Table::TYPE_INTEGER, null, array(
'identity' => true,
'nullable' => false,
'primary ' => true,
))
->addColumn('promotions_name', Varien_Db_Ddl_Table::TYPE_VARCHAR, '255',
))
->addColumn('description', Varien_Db_Ddl_Table::TYPE_TEXT, null, array(
'nullable' => false,
))
->addColumn('image', Varien_Db_Ddl_Table::TYPE_VARCHAR, '255', array(
'nullable' => false,
))
->addColumn('is_enabled', Varien_Db_Ddl_Table::TYPE_TINYINT, '255', array(
'nullable' => false,
))
->addColumn('sort_order', Varien_Db_Ddl_Table::TYPE_VARCHAR, '255' , array(
'nullable' => false,
))
->addColumn('static_blocks', Varien_Db_Ddl_Table::TYPE_TEXT, null,array(
'nullable' => false,
))
->addColumn('category', Varien_Db_Ddl_Table::TYPE_TEXT, null, array(
'nullable' => false,
))
->addColumn('promotions_products', Varien_Db_Ddl_Table::TYPE_TEXT, null, array(
'nullable' => false,
));
$installer->getConnection()->createTable($tablePromotions);
$installer->endSetup();
How can I link a table to this table in which it will be possible to store the id of the products that are linked to this promotion? Thank you)