SQL - 查找两周或更长时间从未登录过的用户

Question

Date        UserID  
1/1/2013    Jo1234   
2/1/2013    Bob1234    
2/2/2013    Bob1234    
2/3/2013    Cal5678  
1/4/2013    Bob1234   
2/1/2013    Bob1234    
2/2/2013    Bob1234    
2/3/2013    Cal5678  

Hi I would like to find the users who didn't log in for two weeks or more

SELECT DISTINCT [UserID]  FROM UsersTable

I cant use WEEK() as I am using an older version of sql I appreciate your help

Answer 1

SELECT DISTINCT [UserID] FROM UsersTable WHERE DATEDIFF(DAY, myDateCol, getDate()) >= 14

Basic date functions are easily found for SQL Server; please check Google for date calculations if you need something more precise.

https://docs.microsoft.com/en-us/sql/t-sql/functions/date-and-time-data-types-and-functions-transact-sql?view=sql-server-ver15

Answer 2

Since you want to filter based on two weeks (14 days), you can use the following to filter the results out :

DATEADD(DAY, -14, GETDATE()

Consider the following dataset :

CREATE TABLE Test(LastDateOfLogin DATE, UserID  NVARCHAR(20))

INSERT INTO Test VALUES('11-Nov-2020', 'Jo1234')
INSERT INTO Test VALUES('01-Nov-2020', 'Bob1234')
INSERT INTO Test VALUES('02-Nov-2020', 'Bob1234')
INSERT INTO Test VALUES('03-Nov-2020', 'Cal5678')
INSERT INTO Test VALUES('03-Nov-2020', 'Bob1234')
INSERT INTO Test VALUES('12-Nov-2020', 'Bob1234')
INSERT INTO Test VALUES('15-Nov-2020', 'Bob1234')
INSERT INTO Test VALUES('05-Nov-2020', 'Cal5678')

The table will look as :

Write the query :

SELECT      LastDateOfLogin, UserID
FROM        Test
WHERE       LastDateOfLogin <= DATEADD(DAY, - 14, GETDATE())

The result will be :

Hope, this helps!!

Answer 3

To answer your part about WEEK(), you are correct. No such thing exists. You have to use DATEPART().

SELECT DATEPART(WW, GETDATE());

I think what you are looking for though is

SELECT DISTINCT [UserID] 
FROM UsersTable
GROUP BY [UserID]
HAVING MAX(Date) < CAST(DATEADD(WEEK, -1, GETDATE()) AS DATE)