tsql - 通过嵌套的 select case 语句过滤存储过程记录

Question

我需要进一步优化来自 this post 的存储过程结果集，我需要过滤结果集以仅显示 emailaddr 为 NULL 的记录(意味着仅显示 Invoice_DeliveryType 值为 'N' 的记录)。

在众多查询中，我尝试过:

select 
    Invoice_ID, 'Unknown' as Invoice_Status, 
    case when Invoice_Printed is null then '' else 'Y' end as Invoice_Printed, 
    case when Invoice_DeliveryDate is null then '' else 'Y' end as Invoice_Delivered, 
    (case when Invoice_DeliveryType <> 'USPS' then ''
          when exists (Select 1
                   from dbo.Client c
                   Where c.Client_ID = SUBSTRING(i.Invoice_ID, 1, 6) and
                         c.emailaddr is not null
                  )
          then 'Y'
          else 'N'
     end)
    Invoice_ContactLName + ', ' + Invoice_ContactFName as ContactName, 
from 
    dbo.Invoice
left outer join 
    dbo.fnInvoiceCurrentStatus() on Invoice_ID = CUST_InvoiceID 
where 
    CUST_StatusID = 7 
    AND Invoice_ID = dbo.Client.Client_ID
    AND dbo.client.emailaddr is NULL
order by 
    Inv_Created  

但是我得到一个错误

The conversion of the nvarchar value '20111028995999' overflowed an int column

如何让存储过程只返回带有 DeliveryType = 'N' 的记录？

Answer 1

尝试将存储过程结果选择到临时表中，然后选择 * 来自#TempTable