Relations¶

Relations connect records across models. Follow the relation target in each model page to understand the surrounding business graph.

Relation types¶

Type	Meaning	Typical read value
`many2one`	This record points to zero or one target record	`false` or `[id, display_name]`
`one2many`	Target records point back to this record	List of target IDs
`many2many`	Both sides can link to multiple records	List of target IDs

For example, the partner_id field on account.move points to res.partner, while its line_ids field points to journal items in account.move.line.

Write many2one values¶

Send the related numeric ID or false:

{
  "vals": {
    "partner_id": 42
  }
}

Write collection relations¶

Odoo uses command triples for one2many and many2many updates:

Command	Form	Purpose
Create	`[0, 0, values]`	Create and link a new target record
Update	`[1, id, values]`	Update a linked record
Delete	`[2, id, 0]`	Delete the target record and relation
Unlink	`[3, id, 0]`	Remove the relation without necessarily deleting the target
Link	`[4, id, 0]`	Link an existing record
Clear	`[5, 0, 0]`	Remove all links
Set	`[6, 0, ids]`	Replace the complete link set

The exact deletion behavior depends on the relation and its inverse field. Review the official ORM command reference before using delete, unlink, clear, or set commands.

Avoid blind replacement

A set command can remove links added by users or other integrations. Read the current value, apply a deliberate change, and handle concurrent updates.