Ondelete Restrict and Ondelete Cascade in Odoo

Abid Patel
17-Oct-2024 Updated : 17-Oct-2024

Learn about ondelete restrict and ondelete cascade in Odoo. Discover how these options affect data deletion and maintain data integrity in your system.

Ondelete Restrict and Ondelete Cascade in Odoo

In Odoo, when creating relationships between models, especially with Many2one fields, it's important to define how the system should behave when related records are deleted. Two common options in Odoo are ondelete='restrict' and ondelete='cascade'. This blog will explain both behaviors and when to use them.

Understanding ondelete='restrict'

The ondelete='restrict' option ensures that a record cannot be deleted if there are other records depending on it. For instance, if a product is linked to a sales order, and the Many2one field connecting them has ondelete='restrict', attempting to delete the product will result in an error if it has related sales orders.

This behavior is essential when you want to prevent accidental deletion of important data. By restricting deletion, you ensure that no orphaned records are created, preserving data integrity across your system.

Example of ondelete='restrict'

Here is an example of using ondelete='restrict' in a Many2one field:

python

class SaleOrder(models.Model):
    _inherit = 'sale.order'

    partner_id = fields.Many2one('res.partner', ondelete='restrict', string='Customer')

In this example, if a customer (partner) is linked to any sales order, you will not be able to delete that customer unless all related sales orders are removed first.

Understanding ondelete='cascade'

The ondelete='cascade' option allows the deletion of related records automatically when the main record is deleted. For example, if you delete a product and the Many2one field linking it to stock movements has ondelete='cascade', all associated stock movements will also be deleted.

This is useful when you want to clean up all related data without manually deleting dependent records. However, caution is required, as this can result in significant data loss if used improperly.

Example of ondelete='cascade'

Here is an example of using ondelete='cascade' in a Many2one field:

python

class StockMove(models.Model):
    _inherit = 'stock.move'

    product_id = fields.Many2one('product.product', ondelete='cascade', string='Product')

In this case, if a product is deleted, all related stock moves will also be deleted automatically. This behavior helps in maintaining consistency and prevents orphan records.

When to Use Restrict vs. Cascade

The choice between ondelete='restrict' and ondelete='cascade' depends on the nature of your data and how you want to handle dependencies:

  • ▹ Use ondelete='restrict' when you need to protect important records and prevent accidental deletion of critical data.
  • ▹ Use ondelete='cascade' when you want to ensure that all related records are cleaned up automatically without manual intervention.

Conclusion

In Odoo, understanding how to use ondelete='restrict' and ondelete='cascade' in your model relationships is crucial for maintaining data integrity and preventing unwanted data loss. Whether you're working with sales orders, stock moves, or any other model, selecting the right behavior will ensure that your system functions correctly and efficiently.

For more details on how to manage relationships between models, check out Odoo’s official documentation or consult with experienced developers to tailor the behavior to your specific needs.

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