Odoo Model Meta Attributes with Examples

This document provides a detailed explanation of the most important meta attributes in Odoo models, along with practical examples where applicable.

1. _name

• Purpose: Technical identifier of the model.
• Example:
  _name = 'library.book'
• This defines a new model accessible via self.env['library.book'].

2. _inherit

• Purpose: Used to extend an existing model.
• Example:
  _inherit = 'res.partner'
• This lets you add fields or override methods in res.partner.

3. _inherits

• Purpose: Delegation inheritance using a foreign key to another model.
• Example:
  _name = 'student.record'
  _inherits = {'res.partner': 'partner_id'}
• partner_id = fields.Many2one('res.partner', required=True)
• Fields of res.partner are accessible as if they belong to student.record.

4. _description

• Purpose: Human-readable name for the model.
• Example:
  _description = 'Library Book Master'
• Used in developer tools and admin UI.

5. _rec_name

• Purpose: Field shown in many2one dropdowns and views.
• Example:
  _rec_name = 'isbn_code'
• isbn_code = fields.Char('ISBN Code')
• Instead of name, isbn_code will display as label.

6. _order

• Purpose: Default sorting order for records.
• Example:
  _order = 'published_date desc, name asc'

7. _sql_constraints

• Purpose: Define SQL constraints for uniqueness or checks.
• Example:
  _sql_constraints = [('unique_isbn', 'UNIQUE(isbn_code)', 'ISBN must be unique!')]

8. _auto

• Purpose: Tells Odoo whether to create a table automatically.
• Default: True
• Example:
  _auto = False  # For SQL views

9. _table

• Purpose: Custom table name in the database.
• Example:
  _table = 'lib_book_master'

10. _log_access

• Purpose: Automatically creates create_uid, create_date, etc.
• Example:
  _log_access = False
• Useful in models like logs or system jobs.

11. _check_company_auto

• Purpose: Enables automatic company consistency checks.
• Example:
  _check_company_auto = True
• Ensures all related records belong to the same company.

12. _register

• Purpose: Controls whether a model is registered.
• Default: True
• Example:
  _register = False  # Used in abstract models

13. _transient

• Purpose: Marks model as temporary (like wizards).
• Default: False
• Example:
  _transient = True
• Auto-deletes after a time period or on restart.

14. _constraints

• Purpose: Older method for Python-based validation (use @api.constrains instead).
• Example:
  def _check_quantity(self):

     for record in self:

         if record.qty < 0:

             return False

     return True

_constraints = [(_check_quantity, 'Quantity cannot be negative', ['qty'])]

✅ Summary Table

Attribute	Purpose	Common Use Case
_name	Defines model name	New custom model
_inherit	Extend existing model	Add fields to res.partner
_inherits	Delegated model composition	Create student.record from partner
_description	UI label for model	Label in developer tools
_rec_name	Record display field	Show code instead of name
_order	Default record order	Sort orders by date
_sql_constraints	Enforce uniqueness or data checks	Ensure email is unique
_auto	Auto-create DB table	Disable for views
_table	Custom DB table name	Use log_entry_table
_log_access	Audit fields like create_uid	Disable for performance or logs
_check_company_auto	Ensure company consistency	Multi-company safety
_register	Register model in Odoo	Disable for abstract base classes
_transient	Auto-delete records	Used in wizards
_constraints	Add Python-based validations	Validate field relationships

These meta attributes offer powerful control over model behavior and structure. Use them carefully to follow Odoo design patterns and ensure clean, maintainable code.