Sql PIVOT，如何使用 PIVOT 将结果中的 NULL 转换为值 0

Posted 2023-03-24

【中文标题】Sql PIVOT，如何使用 PIVOT 将结果中的 NULL 转换为值 0

【英文标题】：Sql PIVOT, How I convert the NULL to value 0 in the Result using PIVOT

【发布时间】：2017-11-04 11:19:40

【问题描述】：

这是正在使用的查询

select * from ( select * from  ( select (Left(CONVERT(date, T_Canteen.vcBillDate, 103),10)) as BillDate ,
ISNULL( SUM( T_CanteenPayment.dPayAmt),0 )as dPayAmt , case ISNULL ( T_CanteenPayment.iPayMode, 0.00) when 15 then 'Cash'
 when 17 then  'eWallet' when 19 then 'Card'  end  as Paymode
 from T_CanteenPayment
inner join T_Canteen on T_Canteen.iKey = T_CanteenPayment.iTransKey 
inner join M_CAN_Outlet on T_Canteen.iOutletKey = M_CAN_Outlet.iKey 
left join   M_Gn_Desk ON M_CAN_Outlet.iDeskKey = M_Gn_Desk.iKey   WHERE T_Canteen.iDelFlg =0 and T_Canteen.iSoftKey  = 42
 and (right(CONVERT(date,T_CanteenPayment.dtPayDt, 103),10))between(right(CONVERT(date,'01/09/2017', 103),10))      
and (right(CONVERT(date,'04/11/2017', 103),10))group by (Left(CONVERT(date, T_Canteen.vcBillDate, 103),10)), T_CanteenPayment.iPayMode , M_CAN_Outlet.vcName  )
 as s 
 PIVOT    
(    
    max ( dPayAmt)
    FOR [Paymode] IN (Cash,  eWallet,Sodexo_Card)    
)AS pvt )as GH 

**我得到了输出**

BillDate    Cash    eWallet Sodexo_Card
----------------------------------------------------
2017-09-01  NULL    110.00  NULL
2017-09-02  NULL    50.00   NULL
2017-09-05  50.00   NULL    NULL
2017-09-06  32.00   3.00    NULL
2017-09-07  28.00   3.00    NULL
2017-09-08  NULL    785.00  NULL

我如何在结果中将 NULL 转换为值 0。请帮忙解决

【问题讨论】：

将列包装在 ISNULL（列名，0）中。没有任何格式就很难阅读你的 SQL。

现在我格式化了查询

它的工作。非常感谢@DavidBeaumont

【参考方案1】：

您可以指定列而不是使用select * 并使用isnull()（或coalesce()）：

select 
    BillDate
  , Cash = isnull(Cash,0)
  , eWallet = isnull(eWallet,0)
  , Sodexo_Card = isnull(Sodexo_Card,0) 
from (....

【参考方案2】：

您的查询会像条件聚合一样简单：

select convert(date, c.vcBillDate) as BillDate ,
       sum(case when cp.iPayMode = 15 then cp.dPayAmt else 0 end) as as cash,
       sum(case when cp.iPayMode = 17 then cp.dPayAmt else 0 end) as as eWalet,
       sum(case when cp.iPayMode = 19 then cp.dPayAmt else 0 end) as as card
from T_CanteenPayment cp inner join
     T_Canteen c
     on c.iKey = cp.iTransKey inner join
     M_CAN_Outlet o
     on c.iOutletKey = o.iKey left join
     M_Gn_Desk d
     on o.iDeskKey = d.iKey
where c.iDelFlg = 0 and
      c.iSoftKey = 42 and
      convert(date, cp.dtPayDt >= '2017-09-01' and '2017-11-04'
group by convert(date, c.vcBillDate)
order by convert(date, c.vcBillDate);

注意事项：

不需要子查询。 对日期使用标准格式可以简化代码并使其更具可读性。 表别名使代码更易于编写和阅读。 M_Gn_Desk 未使用，因此应从查询中删除。