Frequently asked sql query

-- Find Duplicate Record ----

select empname, count(empname) as Duplicate from employee

group by empname having (count (empname)>1) order by empname  desc

---- Find Second Highest Salary---

select min(salary) from employee where

salary in(select top 2 salary from employee order by salary desc )

----- Find Duplicate Name ----

SELECT empname

FROM employee

GROUP BY empname

HAVING ( COUNT(empname) = 1 )

--- Find Duplicate Name ---

SELECT empname, COUNT(*) TotalCount

FROM employee

GROUP BY empname

HAVING COUNT(*) > 1

ORDER BY COUNT(*) DESC

-- Find Duplicate -- 

SELECT empname, COUNT(*) TotalCount

FROM employee

GROUP BY empname

--- Select Duplicate ---

SELECT * FROM dbo.ATTENDANCE WHERE AUTOID NOT IN (SELECT min(AUTOID)

FROM dbo.ATTENDANCE GROUP BY EMPLOYEE_ID,ATTENDANCE_DATE) 

--- Delete Duplicate --- 

DELETE FROM dbo.ATTENDANCE WHERE AUTOID NOT IN (SELECT MIN(AUTOID)

FROM dbo.ATTENDANCE GROUP BY EMPLOYEE_ID,ATTENDANCE_DATE)