operations.py 文件源码

def datetime_trunc_sql( self, lookup_type, field_name, tzname ):
        sql = "TIMESTAMP(SUBSTR(CHAR(%s), 1, %d) || '%s')"
        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() == 'SECOND':
            sql = sql % ( field_name, 19, '.000000' )
        if lookup_type.upper() == 'MINUTE':
            sql = sql % ( field_name, 16, '.00.000000' )
        elif lookup_type.upper() == 'HOUR':
            sql = sql % ( field_name, 13, '.00.00.000000' )
        elif lookup_type.upper() == 'DAY':
            sql = sql % ( field_name, 10, '-00.00.00.000000' )
        elif lookup_type.upper() == 'MONTH':
            sql = sql % ( field_name, 7, '-01-00.00.00.000000' )
        elif lookup_type.upper() == 'YEAR':
            sql = sql % ( field_name, 4, '-01-01-00.00.00.000000' )
        return sql, []