Invalid connector for timedelta: %s.

Package:

django

59414

Exception Class:

DatabaseError

Raise code

            return 'POWER(%s)' % ','.join(sub_expressions)
        elif connector == '#':
            return 'BITXOR(%s)' % ','.join(sub_expressions)
        return super().combine_expression(connector, sub_expressions)

    def combine_duration_expression(self, connector, sub_expressions):
        if connector not in ['+', '-', '*', '/']:
            raise DatabaseError('Invalid connector for timedelta: %s.' % connector)
        fn_params = ["'%s'" % connector] + sub_expressions
        if len(fn_params) > 3:
            raise ValueError('Too many params for timedelta operations.')
        return "django_format_dtdelta(%s)" % ', '.join(fn_params)

    def integer_field_range(self, internal_type):
        # SQLite doesn't enforce any integer constraints

Links to the raise (1)

https://github.com/django/django/blob/7cca22964c09e8dafc313a400c428242404d527a/django/db/backends/sqlite3/operations.py#L355

Ways to fix

Summary: Only certain connectors are supported on deltatime

The latest Django version 3.2.4 tag only support "+" and "-". If other connectors are used, will get the exception

https://github.com/django/django/blob/843c34b3ab921c1acf77ee2014a97bc7975595b8/django/db/backends/sqlite3/operations.py#L344

However in the "main" branch of Django supports "+", "-", "*", and "/". If other connectors are used, will get the exception

https://github.com/django/django/blob/ecf8af79355c8daa67722bd0de946b351f7f613d/django/db/backends/sqlite3/operations.py#L354

Code to reproduce (WRONG): Django version 3.2.4 will not work, but "main" branch will work

from django.db.backends.sqlite3.operations import DatabaseOperations

operations =  DatabaseOperations(connection=None)
operations.combine_duration_expression(connector='*', sub_expressions=['expression'])

Working version (Fixed): Works for both Django version 3.2.4 and "main" branch

from django.db.backends.sqlite3.operations import DatabaseOperations

operations =  DatabaseOperations(connection=None)
operations.combine_duration_expression(connector='+', sub_expressions=['expression'])

Jun 06, 2021

phoang88 615

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