can anybody tell difference between many2one and one2many with example
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hello,
many2one:
This type of field associates this object to a parent object via this Field. For example "Product Category" "Product" belongs to would Many to one. i.e Many Products will belong to a Product Category.
Syntax: field_name = fields.Many2one('object.name', 'Field Name')
Example: category_id = fields.Many2one('product.category', string="category")
# into product table category of product is the example.
one2many:
This field provides a virtual relationship towards multiple objects (inverse of many2one).
Syntax: field_name = fields.One2many('object.name', 'field_id(m2o)', 'Field name')
Example: product_ids = fields.One2many('product.product', 'category_id', string="Products")
# into category the list of products.
Hi Saiharitha,
When you create a many2one field you can select (and set) one value on this field. The code will look like this:
parent_id = fields.Many2one('product.category', string='Parent category')
Which will result in the following in a view:
When you create a one2many you can select (and set) multiple records on this field. The code will look like this (and it has to link to another many2one or many2many):
child_ids = fields.One2many('product.category', 'parent_id', string='Child categories')
Which will result in the following in a view:
So you should use the many2one if you want to set one value (link to one record) and one2many when you want to set multiple values (link to multiple records).
Regards,
Yenthe
HI,
Refer sale order and it's relation with order line:
sale.order has field one2many with order's line, means one order can belongs to many order lines:
order_line = fields.One2many('sale.order.line', 'order_id', string='Order Lines',)
And sale.order.line has field many2one with order's line, means each line only belongs to one order line:
order_id = fields.Many2one('sale.order', string='Order Reference',)
Thanks
Hi,
Two see the difference between the two field types, see this: http://findnerd.com/list/view/Create-many2one-and-one2many-relationship-in-OpenERP/508/
Example:
Many2one: Partner field in the sale order
partner_id = fields.Many2one('res.partner', 'Customer')
One2many: Order lines in the sale Order
order_line = fields.One2many('sale.order.line', 'order_id', string='Order Lines', states={'cancel': [('readonly', True)], 'done': [('readonly', True)]}, copy=True, auto_join=True)
Thanks
in odoo10
These are just mappings, You will mostly find them on any framework which uses a relational database.
One2Many:
Object A can have one or many of objects B (E.g A person can have many cars).
Relationship: A -> B = One -> Many = One2Many
(You can select many cars while creating a person).
Many2one:
Object B can only have one object of A.
(E.g A car is owned by one person also many cars can be owned by the same person).
Relationship: B -> A = Many -> One = Many2One