Environment
The Environment stores various contextual data(上下文数据 ) used by the ORM: the database cursor (for database queries), the current user (for access rights checking) and the current context (storing arbitrary metadata). The environment also stores caches.
All recordsets have an environment, which is immutable(不可改变的), can be accessed using env and gives access to the current user (user), the cursor (cr) or the context (context):
>>> records.env
<Environment object ...>
>>> records.env.user
res.user(3)
>>> records.env.cr
<Cursor object ...)
When creating a recordset from an other recordset, the environment is inherited. The environment can be used to get an empty recordset in an other model, and query that model:
>>> self.env['res.partner']
res.partner
>>> self.env['res.partner'].search([['is_company', '=', True], ['customer', '=', True]])
res.partner(7, 18, 12, 14, 17, 19, 8, 31, 26, 16, 13, 20, 30, 22, 29, 15, 23, 28, 74)
Altering the environment
The environment can be customized from a recordset. This returns a new version of the recordset using the altered environment.
sudo()-
creates a new environment with the provided user set, uses the administrator if none is provided (to bypass access rights/rules in safe contexts), returns a copy of the recordset it is called on using the new environment:
# create partner object as administrator
env['res.partner'].sudo().create({'name': "A Partner"}) # list partners visible by the "public" user
public = env.ref('base.public_user')
env['res.partner'].sudo(public).search([]) with_context()-
- can take a single positional parameter, which replaces the current environment's context
- can take any number of parameters by keyword, which are added to either the current environment's context or the context set during step 1
# look for partner, or create one with specified timezone if none is
# found
env['res.partner'].with_context(tz=a_tz).find_or_create(email_address) with_env()- replaces the existing environment entirely