用于3个子查询的SQL查询，具有自联接功能

请提供一些建议，如何实现以下要求的输出

Table1 data
-----------
request_id    record_type  invoice_number      merchant_info          transaction_info
----------    -----------  -----------------   ----------------    -----------------------
123             01              NULL                NULL                  Trans1
123             30              NULL                Merc1                  NULL
123             02              Invoice1            NULL                   NULL
123             01              NULL                NULL                   Trans2
123             30              NULL                Merc2                  NULL
123             02              Invoice2            NULL                   NULL
124             01              NULL                NULL                  Trans3
124             30              NULL                Merc3                 NULL
124             02              Invoice3            NULL                   NULL
124             01              NULL                NULL                   Trans4
124             30              NULL                Merc4                  NULL
124             02              Invoice4            NULL                   NULL

所需输出

---------------
invoice_number      merchant_info          transaction_info
--------------     --------------           -----------------
Invoice1             Merc1                     Trans1
Invoice2             Merc2                     Trans2
Invoice3             Merc3                     Trans3
Invoice4             Merc4                     Trans4



SELECT xpt.transaction_info,XTG.merchant_info,x.invoice_number
FROM (select * from table1
WHERE record_type='01' )xpt,
 (SELECT *
 FROM table1
 WHERE record_type='30'
 ) XTG,
 (SELECT *
 FROM table1
 WHERE record_type='02'
 and invoice_number is not null
 ) X
 WHERE 1=1 
 and xtg.request_id=xpt.request_id
and x.request_id=xpt.request_id

只需使用聚合：

select request_id, max(invoice_number) as invoice_number,
       max(merchant_info) as merchant_info,
       max(transaction_info) as transaction_info
from table1
group by request_id;

select max (decode ( record_type, '01', transaction_info, null)) as transaction_info, 
       max (decode ( record_type, '30', merchant_info,    null)) as merchant_info,
       max (decode ( record_type, '02', invoice_number,   null)) as invoice_number
from table1
group by request_id

只需使用聚合：

select request_id, max(invoice_number) as invoice_number,
       max(merchant_info) as merchant_info,
       max(transaction_info) as transaction_info
from table1
group by request_id;

select max (decode ( record_type, '01', transaction_info, null)) as transaction_info, 
       max (decode ( record_type, '30', merchant_info,    null)) as merchant_info,
       max (decode ( record_type, '02', invoice_number,   null)) as invoice_number
from table1
group by request_id

---

尝试一些条件聚合：

select request_id, max(invoice_number) as invoice_number,
       max(merchant_info) as merchant_info,
       max(transaction_info) as transaction_info
from table1
group by request_id;

select max (decode ( record_type, '01', transaction_info, null)) as transaction_info, 
       max (decode ( record_type, '30', merchant_info,    null)) as merchant_info,
       max (decode ( record_type, '02', invoice_number,   null)) as invoice_number
from table1
group by request_id

---

尝试一些条件聚合：

select request_id, max(invoice_number) as invoice_number,
       max(merchant_info) as merchant_info,
       max(transaction_info) as transaction_info
from table1
group by request_id;

select max (decode ( record_type, '01', transaction_info, null)) as transaction_info, 
       max (decode ( record_type, '30', merchant_info,    null)) as merchant_info,
       max (decode ( record_type, '02', invoice_number,   null)) as invoice_number
from table1
group by request_id

---

选择发票号…

和

按请求分组\u id

？我们不需要分组数据。此外，每个记录都会为一个或多个字段返回空值。我们提供了样本数据。根据这一点，我们要求同样的。不是分组数据。请注意，我看到一个表有3条记录，一个输出有1行，其中包含来自每个表记录的数据，这似乎是分组。如果没有，你能举个更清楚的例子吗？@jarlh。我很尴尬。干杯。我还是不太清楚<代码>发票1和

发票2

具有相同的

请求id

和

记录类型

；那么，我怎么能说

Invoice1

匹配

Merc1

和

Trans1

而不是

Merc2

或

Trans2

。您的数据中是否有订单？

选择发票号…

和

按请求分组\u id

？我们不需要分组数据。此外，每个记录都会为一个或多个字段返回空值。我们提供了样本数据。根据这一点，我们要求同样的。不是分组数据。请注意，我看到一个表有3条记录，一个输出有1行，其中包含来自每个表记录的数据，这似乎是分组。如果没有，你能举个更清楚的例子吗？@jarlh。我很尴尬。干杯。我还是不太清楚<代码>发票1和

发票2

具有相同的

请求id

和

记录类型

；那么，我怎么能说

Invoice1

匹配

Merc1

和

Trans1

而不是

Merc2

或

Trans2

。您的数据中是否有任何排序？