operations.py 文件源码

def datetime_extract_sql(self, lookup_type, field_name, tzname):
        if settings.USE_TZ:
            hr, min = self._get_utcoffset(tzname)
            if hr < 0:
                field_name = "%s - %s HOURS - %s MINUTES" % (field_name, -hr, -min)
            else:
                field_name = "%s + %s HOURS + %s MINUTES" % (field_name, hr, min)

        if lookup_type.upper() == 'WEEK_DAY':
            return " DAYOFWEEK(%s) " % ( field_name ), []
        else:
            return " %s(%s) " % ( lookup_type.upper(), field_name ), []

    # Truncating the date value on the basic of lookup type.
    # e.g If input is 2008-12-04 and month then output will be 2008-12-01 00:00:00
    # Reference: http://www.ibm.com/developerworks/data/library/samples/db2/0205udfs/index.html