選擇結果不完整？

Question

我想運行此查詢，但myfield不包含完整的電子郵件地址，姓氏，電話和電子郵件促銷值？它看起來像myField的長度有限制？

SQL語句：

use adventureworks 
go 

select si.CustomerID, 
'myField' = 
      CASE 
       When (Select Top 1 FirstName+ ' ' + MiddleName + ' '+ Phone + ' ' + EmailAddress +' '+ LastName + ' ' + Phone + ' ' + cast(EmailPromotion as varchar) From Person.Contact pc Where si.ContactID = pc.contactid) is not null Then 
      Cast((Select Top 1 FirstName+ ' ' + MiddleName + ' ' + Phone + ' ' +EmailAddress +' '+ LastName + ' ' + Phone + ' ' + cast(EmailPromotion as varchar) From Person.Contact pc Where si.ContactID = pc.contactid ) As varchar) 
      Else '' 
      END 

from Sales.Individual si 
where si.CustomerID=11000 

Answer 1

對於varchar[(n)]：

當在數據定義或變量聲明 語句未指定n，則默認長度爲1。當不與 CAST函數指定n，則默認長度爲30

所以明確地在CAST，例如指定一個適當長的長度varchar(256)

Ref。