物理外键拓展

Postgresql数据库端不建立外键关系，odoo ORM保留外键关系

组件使用方式，在外键字段上设置属性db_constraint=False，将会在数据库层将外键关系解除，保留orm层的外键关系

class Author(models.Model):
    name = 'xcj.author'
    name = fields.Char(string="姓名")
    bookids = fields.One2many("xcj.book", "author_id", string="作品")

class Book(models.Model):
    name = 'xcj.book'
    name = fields.Char(string="数目")
    code = fields.Char(string="编号")
    authorid = fields.Many2one("xcj.author", string="作者", dbconstraint=False)
    authorids = fields.Many2many("xcj.author", "xcjbookauthors", "bookid", "authorid", string="作者", db_constraint=False)

设置为True或者不配置db_constraint

author_id = fields.Many2one("xcj.author", string="作者")
author_ids = fields.Many2many("xcj.author", "xcj_book_authors", "book_id", "author_id", string="作者")

或

author_id = fields.Many2one("xcj.author", string="作者", db_constraint=True)
author_ids = fields.Many2many("xcj.author", "xcj_book_authors", "book_id", "author_id", string="作者", db_constraint=True)

设置为False（将不会建立数据库层面的外键关系）

author_id = fields.Many2one("xcj.author", string="作者", db_constraint=False)
author_ids = fields.Many2many("xcj.author", "xcj_book_authors", "book_id", "author_id", string="作者", db_constraint=False)