operations.py 文件源码

 复制代码def datetime_trunc_sql(self, lookup_type, field_name, tzname):
        # Django 1.6
        if settings.USE_TZ:
            field_name = "CONVERT_TZ({0}, 'UTC', %s)".format(field_name)
            params = [tzname]
        else:
            params = []
        fields = ['year', 'month', 'day', 'hour', 'minute', 'second']
        format_ = ('%Y-', '%m', '-%d', ' %H:', '%i', ':%S')
        format_def = ('0000-', '01', '-01', ' 00:', '00', ':00')
        try:
            i = fields.index(lookup_type) + 1
        except ValueError:
            sql = field_name
        else:
            format_str = ''.join([f for f in format_[:i]] +
                                 [f for f in format_def[i:]])
            sql = "CAST(DATE_FORMAT({0}, '{1}') AS DATETIME)".format(
                field_name, format_str)
        return sql, params