A Complete Overview of Fields in Odoo 19

Fields are the backbone of any Odoo application. In Odoo 19, fields define how data is stored, displayed, validated, and interacted with across models, views, and business logic. Whether you are working on ERP modules, custom addons, or large-scale enterprise solutions, understanding Odoo fields deeply is essential. This guide provides a complete, structured, and practical overview of all major field types in Odoo 19, with explanations, examples, and real-world use cases.

1. What Are Fields in Odoo?

In Odoo, a field represents a column in a database table and an attribute of a model (`models.Model`). Fields are declared as Python class attributes and are handled by Odoo’s ORM (Object Relational Mapping).

from odoo import models, fields

class Product(models.Model):
    _name = 'custom.product'

    name = fields.Char(string='Product Name')

Each field controls:

• Data type (string, number, date, relation, etc.)
• Database storage
• UI rendering in views
• Validation and constraints

2. Basic (Simple) Field Types

2.1 Char

Stores short text (VARCHAR).

name = fields.Char(string="Name", required=True)

Use case: Names, titles, codes

2.2 Text

Stores long text (TEXT).

description = fields.Text(string="Description")

Use case: Notes, comments, descriptions

2.3 Html

Stores HTML content with rich-text editor support.

content = fields.Html(string="Content")

Use case: Email templates, product descriptions

2.4 Integer

Stores whole numbers.

quantity = fields.Integer(string="Quantity")

2.5 Float

Stores decimal numbers.

price = fields.Float(string="Price")

2.6 Monetary

Float field linked with currency.

price = fields.Monetary(string="Price", currency_field='currency_id')
currency_id = fields.Many2one('res.currency')

Use case: Financial values

2.7 Boolean

Stores True/False.

active = fields.Boolean(string="Active", default=True)

3. Date & Time Fields

3.1 Date

Stores date only.

start_date = fields.Date(string="Start Date")

3.2 Datetime

Stores date and time (UTC-based).

created_on = fields.Datetime(string="Created On")

4. Selection Fields

Selection fields allow choosing one value from a predefined list.

state = fields.Selection([
    ('draft', 'Draft'),
    ('confirmed', 'Confirmed'),
    ('done', 'Done')
], string="Status", default='draft')

Use case: Status workflows, categories

5. Relational Fields (ORM Power)

5.1 Many2one

Links one record to another.

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

Database: Foreign key

5.2 One2many

Inverse of Many2one (not stored directly).

order_line_ids = fields.One2many('sale.order.line', 'order_id', string="Order Lines")

5.3 Many2many

Many-to-many relationship.

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

Database: Relation table

6. Computed Fields

Fields whose value is calculated dynamically.

amount_total = fields.Float(compute='_compute_amount')

@api.depends('price', 'quantity')
def _compute_amount(self):
    for rec in self:
        rec.amount_total = rec.price * rec.quantity

Key Options

• compute
• store=True (persist in DB)
• @api.depends

7. Related Fields

Fields that mirror another field.

partner_email = fields.Char(related='partner_id.email', store=True)

Use case: Avoid joins, improve reporting

8. Default Values

is_active = fields.Boolean(default=True)

name = fields.Char(default=lambda self: 'New')

9. Field Attributes (Very Important)

Example:

name = fields.Char(
    string="Name",
    required=True,
    tracking=True,
    help="Enter record name"
)

10. Domain & Context in Fields

Domain

Filters selectable records.

partner_id = fields.Many2one(
    'res.partner',
    domain=[('is_company', '=', True)]
)

Context

Pass extra parameters.

partner_id = fields.Many2one(
    'res.partner',
    context={'show_address': True}
)

11. Onchange Fields

Update values on UI change (no DB write).

@api.onchange('quantity')
def _onchange_quantity(self):
    if self.quantity < 0:
        self.quantity = 0

12. Constraints (Validation)

SQL Constraint

_sql_constraints = [
    ('unique_name', 'unique(name)', 'Name must be unique!')
]

Python Constraint

@api.constrains('age')
def _check_age(self):
    for rec in self:
        if rec.age < 18:
            raise ValidationError('Age must be 18+')

13. Company & Multi-Company Fields

company_id = fields.Many2one(
    'res.company',
    default=lambda self: self.env.company
)

14. Special & Advanced Fields

• Binary – File upload
• Image – Image with resizing
• Reference – Dynamic model reference
• Properties – Dynamic property fields

image_1920 = fields.Image(max_width=1920, max_height=1920)

15. Fields & Views Relationship

Fields control rendering in:

• Form View
• Tree View
• Kanban View
• Search View

Example:

xml 

16. Best Practices

• Use store=True only when needed
• Prefer related over duplicate fields
• Always define string
• Index frequently searched fields
• Avoid heavy compute without depends

17. Conclusion

Fields in Odoo 19 are powerful, flexible, and deeply integrated with the ORM, UI, and business logic. Mastering fields means mastering Odoo development itself.

If you understand:

• Field types
• Relations
• Computed & related fields
• Constraints & attributes