odoo-fields-and-orm

name	Odoo Fields and ORM
description	Comprehensive guide to Odoo fields, including basic, relational, computed, and robust technical features (indexing, company_dependent, properties).

Odoo Fields and ORM

Goal

Define robust models and fields, leveraging advanced ORM features for performance, multi-company support, and dynamic customization.

1. Functional Requirements Checklist

Before defining a field, answer these questions to determine the correct attributes:

• Search/Group: Does it need to be searchable or groupable? -> store=True (default for non-computed), index=True
• Performance: Is it a large text field requiring fuzzy search? -> index='trigram'
• Multi-Company: Does the value vary per company (e.g., Cost Price)? -> company_dependent=True
• Consistency: Should it strictly respect company boundaries? -> check_company=True
• Pre-calculation: Should it be computed before the record is created (e.g., for default values)? -> precompute=True (Odoo 17+)
• Dynamic Data: Do users need to define custom fields per record without schema changes? -> Properties field.

2. Defining a Model

Models inherit from models.Model, models.TransientModel (temporary), or models.AbstractModel (mixins).

Model Types

1. Model (models.Model):
   • Regular database-persisted models.
   • Most common type.
2. TransientModel (models.TransientModel):
   • Temporary records, periodically cleaned up by a scheduled action.
   • Used for Wizards (pop-ups to ask user input).
   • No access rights required (usually).
   • Example: class EstateOfferWizard(models.TransientModel): ...
3. AbstractModel (models.AbstractModel):
   • No database table created.
   • Used as a "Mixin" or Interface to be inherited by other models.
   • Example: mail.thread (Chatter), image.mixin.

from odoo import api, fields, models

class EstateProperty(models.Model):
    _name = "estate.property"
    _description = "Real Estate Property"
    _order = "id desc"
    _rec_name = "name"  # Field to use for display name

    # Robust: Prevent access by malicious users
    _allow_sudo_commands = False 

3. Basic & Advanced Fields

Defined in odoo/odoo/orm/fields.py.

Field Type	Python Type	SQL Type	Notes
Char	str	VARCHAR	Short text.
Text	str	TEXT	Long text.
Integer	int	INTEGER
Float	float	FLOAT
Boolean	bool	BOOLEAN
Date	date	DATE	fields.Date.today()
Datetime	datetime	TIMESTAMP	fields.Datetime.now()
Binary	bytes	BYTEA	Encoded in base64.
Json	dict/list	JSONB	Store structured data (Odoo 17+).
Properties	dict	JSONB	Robust: Pseudo-fields defined on a parent container.

Common Attributes

• string="Label": UI Label.
• required=True: NOT NULL constraint.
• readonly=True: UI only (unless compute is used).
• copy=False: Don't copy this value when duplicating the record.
• default=...: Static value or callable (lambda self: ...).
• groups="base.group_user": Restrict access to specific security groups.

Robust Attributes

• index=True / 'btree' / 'btree_not_null' / 'trigram':
  • 'btree_not_null': Better performance if many values are NULL.
  • 'trigram': Enables partial matching (ilike) acceleration (requires pg_trgm).
• company_dependent=True: Stores values as JSONB {'company_id': value}.
• aggregator='sum'/'avg'/'max': Default aggregation function for Group By.

4. Computed Fields

Fields whose values are calculated via Python.

@api.depends("living_area", "garden_area")
def _compute_total_area(self):
    for record in self:
        record.total_area = record.living_area + record.garden_area

Attribute	Description	Robust Tip
store=True	Store in DB. Recomputed when dependencies change.	Essential for searching/grouping.
compute_sudo=True	Compute as superuser.	Default for store=True.
precompute=True	Compute before insert.	New: Optimization for default-like behavior on creation.
recursive=True	Allow recursive dependencies.	handle self-referencing computations.

5. Relational Fields

Link models together.

Many2one

Link to a parents.

partner_id = fields.Many2one("res.partner", string="Partner", ondelete="restrict", index=True)

• ondelete: set null (default), restrict (prevent deletion), cascade (delete child).
• domain: Filter selectable records (e.g., [('is_company', '=', True)]).

One2many

Link to children (inverse of Many2one).

offer_ids = fields.One2many("estate.offer", "property_id", string="Offers")

Many2many

Link to multiple records (M<->M table).

tag_ids = fields.Many2many("estate.tag", string="Tags")

Robust Relational Features

• check_company=True: Ensures partner_id.company_id == self.company_id. Critical for multi-company security.
• context={'active_test': False}: Include archived records in the relation.

6. Onchanges (@api.onchange)

Client-side UI logic. Not for data consistency (use computed fields for that).

@api.onchange("partner_id")
def _onchange_partner_id(self):
    if self.partner_id:
        self.phone = self.partner_id.phone

7. The Properties Field (Advanced)

Allows defining fields dynamically per record, based on a "definition" from a container record.

• Use Case: A "Product" has different specifications depending on the "Category".
• Defined in odoo/odoo/orm/fields_properties.py.

# Definition on Container (e.g., Category)
properties_definition = fields.PropertiesDefinition('Properties')

# Value on Child (e.g., Product)
properties = fields.Properties(
    string='Properties',
    definition='category_id.properties_definition',
)