Question

我有以下表格，我想进行可以给出结果5的查询（如下面的粗体所示）。

我试图查询，但是你不能帮忙吗？

 SELECT utl_reader_route.reader_route_code, 
       utl_reader_route_date.read_date 
FROM   utl_reader_route_date 
       JOIN utl_reader_route 
         ON utl_reader_route.reader_route_id = 
            utl_reader_route_date.reader_route_id 
       JOIN utl_meter_reader 
         ON utl_reader_route.meter_reader_id = utl_meter_reader.meter_reader_id 
WHERE  utl_meter_reader.meter_reader_code = 'ADR MRS' 
       AND utl_reader_route_date.read_date BETWEEN '2014-05-01' AND '2014-05-31' 
ORDER  BY read_date

utl_meter_reader

meter_reader_id ......... meter_reader_code

1 ......... ADR MRS

2 ......... AGC

utl_reader_route

reader_route_id .......... meter_reader_id

1 ......... 1

2 ......... 2

utl_reader_route_date

reader_route_date_id ......... reader_route_id ......... read_date

1 ......... 1 ......... 20/04/2014

1 ......... 2 ......... 20/20/2014

1 ......... 3 ......... 20/06/2014

2 ......... 4 ......... 20/04/2014

2 ......... 5 .........

2 ......... 6 ......... 20/06/2014

3 ......... 7 ......... 20/04/2014

3 ......... 8 ......... 20/20/2014

3 ......... 9 ......... 20/06/2014

Answer 1

假设您需要没有日期的记录。您可以输入Or子句并检查

之类的空日期

select utl_reader_route.reader_route_code,utl_reader_route_date.read_date from 
utl_reader_route_date join utl_reader_route on  
utl_reader_route.reader_route_id=utl_reader_route_date.reader_route_id Join 
utl_meter_reader on utl_reader_route.meter_reader_id=utl_meter_reader.meter_reader_id      where 

utl_meter_reader.meter_reader_code='ADR MRS' and utl_reader_route_date.read_date between '2014-05-01' and '2014-05-31' Or utl_reader_route_date.read_date is Null order by read_date

加入日期之间

1 个答案: