Top N Salary in SQL

Top 2 Salary from each Department:

+-----+------+-----------+-------+----------+-------+------+

|empno| ename|designation|manager| hire_date|    sal|deptno|

+-----+------+-----------+-------+----------+-------+------+

| 7369| SMITH|      CLERK|   7902|1980-12-17| 800.00|    20|

| 7499| ALLEN|   SALESMAN|   7698|1981-02-20|1600.00|    30|

| 7521|  WARD|   SALESMAN|   7698|1981-02-22|1250.00|    30|

| 7566| JONES|    MANAGER|   7839|1981-04-02|2975.00|    20|

| 7654|MARTIN|   SALESMAN|   7698|1981-09-28|1250.00|    30|

| 7698| BLAKE|    MANAGER|   7839|1981-05-01|2850.00|    30|

| 7782| CLARK|    MANAGER|   7839|1981-06-09|2450.00|    10|

| 7788| SCOTT|    ANALYST|   7566|1982-12-09|3000.00|    20|

| 7839|  KING|  PRESIDENT|   NULL|1981-11-17|5000.00|    10|

| 7844|TURNER|   SALESMAN|   7698|1981-09-08|1500.00|    30|

| 7876| ADAMS|      CLERK|   7788|1983-01-12|1100.00|    20|

| 7900| JAMES|      CLERK|   7698|1981-12-03| 950.00|    30|

| 7902|  FORD|    ANALYST|   7566|1981-12-03|3000.00|    20|

| 7934|MILLER|      CLERK|   7782|1982-01-23|1300.00|    10|

+-----+------+-----------+-------+----------+-------+------+

+------+----------+--------+

|deptno|     dname|     loc|

+------+----------+--------+

|    10|ACCOUNTING|NEW YORK|

|    20|  RESEARCH|  DALLAS|

|    30|     SALES| CHICAGO|

|    40|OPERATIONS|  BOSTON|

+------+----------+--------+

Solution-1:

select e.ename,
       d.dname,
       e.sal 

          from emp e join dept d 

          on e.deptno = d.deptno 

          where e.sal in  

          (

          select sal from  

          ( 

            select ename,
                  salary,
                  deptno,
                  DENSE_RANK() over(partition by deptno                      order by sal desc)rn from emp)rn1 

                  where rn1.rn <=2);