Please correct me on the following code in Odoo

Question

This is the following code in Odoo and does not work as I expected.

 def _check_dates(self, cr, uid, ids, context=None):    
    for rec in self.browse(cr, uid, ids, context=context):
        if rec.rdate and rec.gdate :
        start = date.strftime(str(rec.rdate), "%Y-%m-%d")
        end = date.strftime(str(rec.gdate), "%Y-%m-%d")
        if start >= end:
                return False
    return True

    _constraints = [
        (_check_dates, 'Error ! Received Date must be less or equal than given Date', ['rdate'])
        ]

Please correct me anyone. Thanks

Answer 1

Using the new Odoo 8 ORM API (no need to add anything to the _constraints list, which is now deprecated):

@api.one
@api.constrains('rdate', 'gdate')
def _check_dates(self):
    if self.rdate and self.gdate:
        start = fields.Date.from_string(self.rdate)
        end = fields.Date.from_string(self.gdate)
        if start > end:
            raise exceptions.ValidationError("Error! Received Date must be less or equal than given Date")

Note: I changed start >= end to start > end to make it consistent with your error message (since the previous code didn't accept equal dates).

---

Alternatively you can set it up as an SQL constraint, which has the benefit of working on a deeper, database level:

_sql_constraints = [
    (
        'rdate_gdate_check',
        'check(rdate <= gdate)',
        "Error! Received Date must be less or equal than given Date",
    ),
]