Employee Register Log
(Download the CSV file used)

/* To see the file*/  

SELECT * from EmployeeLog;  

Day	Employee	Present
Mon	Alvin	1
Mon	Simon	1
Mon	Theodore	1
Mon	Jim	0
Tues	Alvin	1
Tues	Simon	0
Tues	Theodore	1
Tues	Jim	0
Weds	Alvin	0
Weds	Simon	1
Weds	Theodore	1
Weds	Jim	1
Thurs	Alvin	1
Thurs	Simon	1
Thurs	Theodore	0
Thurs	Jim	1
Fri	Alvin	0
Fri	Simon	1
Fri	Theodore	1
Fri	Jim	0

/* To see how many days of the weeek each employee worked */  

SELECT Employee, SUM(Present) AS Total_Present_Days  
FROM EmployeeLog  
GROUP BY Employee  
ORDER BY Total_Present_Days DESC;  

/* Find the most consecutive days worked per employee, and order descending */  

WITH ConsecutiveDays AS (  
    SELECT   
        Employee,  
        Present,  
        ROW_NUMBER() OVER (PARTITION BY Employee, Present ORDER BY Day) -   
        ROW_NUMBER() OVER (PARTITION BY Employee ORDER BY Day) AS ConsecutiveGroup  
    FROM EmployeeLog  
)  
, ConsecutiveStreaks AS (  
    SELECT  
        Employee,  
        MAX(COUNT(*)) AS MaxConsecutiveDays  
    FROM ConsecutiveDays  
    WHERE Present = 1  
    GROUP BY Employee, ConsecutiveGroup  
)  
SELECT  
    Employee,  
    MAX(MaxConsecutiveDays) AS Max_Consecutive_Days  
FROM ConsecutiveStreaks  
GROUP BY Employee  
ORDER BY Max_Consecutive_Days DESC;