SQL选择具有特定状态的特定学生的最新记录

Question

请帮我选择状态= 1的每位学生的最新记录。我有一个名为stdData和列

的表

 Student ID    FDate        Status
     12        2014-03-12      1
     12        2014-03-15      1 
     13        2014-02-03      1 
     13        2014-02-04      0
     13        2014-02-05      1

如何选择状态= 1的每位学生的最新记录？

Answer 1

您需要使用group by

select student_id, max(date)
from table_name
where status=1
group by student_id;

fiddle

Answer 2

在此查询中很明显status = 1我将其添加到我的选择中，如下所示：

Select Student_ID ,max(Date) Date, 1 status From table1 
where status = 1 Group by Student_ID;

SQL Fiddle

Answer 3

如果您使用的是sql server，请尝试使用

Select top(1) * from StudentTable where status =1 order by student_id desc

Answer 4

试试这个！

SELECT LAST(column_name) FROM table_name;

Answer 5

试试这个！

;with cte as
(
select *,rn=row_number() over(partition by Student_Id order by Date desc) from #t
)

select * from cte where rn=1 and status=1

SEE DEMO

Answer 6

在Sqlserver

中

Create table Student(
ID int identity(1,1) primary key not null,
S_Date datetime,
Status bit
)

insert  into Student values ('2014-03-11',1)
insert  into Student values ('2014-03-12',0)
insert  into Student values ('2014-03-13',1)
insert  into Student values ('2014-03-14',0)
insert  into Student values ('2014-03-15',1)

select top 1 * from Student where Status=1 Order By S_Date Desc

Answer 7

您可以使用ROW_NUMBER功能来实现此目的：

SELECT Student_ID,  Date , Status
 FROM 
(
  SELECT ROW_NUMBER() OVER (PARTITION BY Student_ID ORDER BY Date  DESC) AS rn, Student_ID,  Date , Status
  FROM your_table 
  WHERE Status = 1
) tab
WHERE tab.rn = 1