Question

基本上我想要的是将出现在[借用日期]旁边的列
此列将称为“状态”，它将有两个值
这些值取决于以下条件：如果今天的日期比[借用的日期]大3天，则“状态”列=过期，否则它应显示“未过期”

这是我的代码。

SELECT dbo.borrowing.[book_id], 
       dbo.bookregistration.[book_title], 
       dbo.bookregistration.[book_category], 
       dbo.bookregistration.[book_type], 
       dbo.bookregistration.edition, 
       dbo.borrowing.[borrowed_date], 
       dbo.borrowing.[adm_no] 
FROM   dbo.bookregistration 
INNER JOIN dbo.borrowing ON dbo.bookregistration.[book_id] = dbo.borrowing.[book_id]

Answer 1

这是您的查询。首先，我们将使用my_datframe.to_csv('file_name.csv')使其更短，第二次使用alias

这是您的完整查询。

select case

Answer 2

您可以使用DATE_ADD和CASE语句满足以下要求-

String

Answer 3

SELECT id
    ,date
    ,first_value(id) over (partition by id order by date) = date as first
FROM table_name;

Answer 4

尝试一下：

 SELECT
      B.[Book_ID]
      , BR.[Book_Title]
      , BR.[Book_Category]
      , BR.[Book_Type]
      , BR.Edition
      , CASE WHEN DATE_ADD([B.Borrowed_Date], INTERVAL 3 DAY) > GetDate() THEN 'Not Overdue' ELSE 'Overdue' END Status
      , BR.[Adm_NO]   
 FROM dbo.BookRegistration BR
 INNER JOIN dbo.Borrowing B ON BR.[Book_ID] = B.[Book_ID]

Answer 5

我们在这里：

SELECT dbo.Borrowing.[Book_ID], dbo.BookRegistration.[Book_Title]
    , dbo.BookRegistration.[Book_Category], dbo.BookRegistration.[Book_Type]
    , dbo.BookRegistration.Edition, dbo.Borrowing.[Borrowed_Date] AS [Borrowed_Date]
    , case when DATEADD(DD,3,[Borrowed_Date]) > GETDATE() THEN 'Not Overdue' ELSE 'Overdue' END AS Status
    , dbo.Borrowing.[Adm_NO]
FROM dbo.BookRegistration
INNER JOIN dbo.Borrowing ON dbo.BookRegistration.[Book_ID] = dbo.Borrowing.[Book_ID]

添加基于日期[借入日期]给出否或是的列

5 个答案: