Question

我有一个用户表，该表包含具有多个用户的多个客户端，每个用户的最后登录日期。我需要获取每个客户端的最新登录用户的日期。我已经尝试过max（date），但是这使我获得了每个客户端的每个用户的最后登录日期。

我的目标是让每个客户拥有一个最新登录日期的用户。

clc
clear
close all

revenue = ones(100,1);
opex = -1*ones(100,1);
opex(10:15,1) = 3;

revenueNeg = revenue;
revenueNeg(revenueNeg>0) = 0;
revenuePos = revenue;
revenuePos(revenuePos<0) = 0;
opexNeg = opex;
opexNeg(opexNeg>0) = 0;
opexPos = opex;
opexPos(opexPos<0) = 0;
yDataNeg = [revenueNeg, opexNeg];
yDataPos = [revenuePos, opexPos];
hold on;
bar(yDataNeg,'stack')
bar(yDataPos,'stack')
legend('Revenue','Opex');
hold off;

我正在寻找用户的登录日期最近的地方

 SELECT DISTINCT(u.clientid),u.userid,Max(u.lastLogin) as lastLogin
 FROM users u
 WHERE u.clientid IN (10,20,30,40)
 GROUP BY u.clientid,u.userid,u.lastLogin

 clientid  userid  lastLogin
    10        1      a date
    10        2      a date
    10        3      a date
    20        4      a date
    20        5      a date
    30        6      a date
    30        7      a date
    30        8      a date
    30        9      a date
    and so on

Answer 1

以下示例脚本使用row_number()和CTE来获取每个具有最后登录名的客户端的用户请根据您的表结构和列名更新脚本。

declare @mytable as table(client varchar(50),myuser varchar(50),lastlogin datetime)

insert into @mytable values
('client1','user11','2019-06-15 2:57PM'),
('client1','user12','2019-06-12 7:47PM'),
('client2','user21','2019-06-13 8:30PM'),
('client2','user22','2019-06-17 9:00AM'),
('client3','user31','2019-06-10 10:57PM'),
('client3','user32','2019-06-10 11:57PM')

;with cte as(
select client,myuser,lastlogin,row_number() over(partition by client order by lastlogin desc) r# from @mytable )
select * from cte where r#=1

MS SQL Server最后一个用户登录到具有多个用户的多个客户端

1 个答案: