SQL Server：插入日期返回錯誤的值

Question

當我試圖插入另一個表中的信息時，它應該是空的時候從date列返回'1900-01-01'。在導入表上，數據類型爲varchar，我想在表中插入信息是date數據類型。有在EndDate列一些空值應插入爲空，但它返回「1900-01-01」

Insert into tblServiceHistory (PersonID, PositionID, CommitteeID,StartDate, EndDate) 
    Select distinct 
     PersonID, PositionID, CommitteeID, StartDate, EndDate 
    From 
     tblCommitteeOfficers_IMPORT 
    Where 
     PersonID is not null 
     And StartDate is not null 
     And PositionID is not null 
     And CommitteeID is not null 

Answer 1

轉換爲日期空白弦翻中'1900-01-01'。

例如select convert(date,'')返回'1900-01-01'。

您可以使用nullif()在您的select中將空字符串變成null值。

試試這個：

Insert into tblServiceHistory (PersonID, PositionID, CommitteeID,StartDate, EndDate) 
Select distinct PersonID, PositionID, CommitteeID, nullif(StartDate,''), nullif(EndDate,'') 
From tblCommitteeOfficers_IMPORT 
Where PersonID is not null 
    AND nullif(StartDate,'') is not null 
    AND PositionID is not null 
    AND CommitteeID is not null