What is the query to find nth highest salary?
What is the use of cursors?
Answer Posted / suraj kedia
There are 3 ways to find out the nth highest salary in a
given table (e.g. emp) as below;
1) select distinct sal from emp e1 where &n=(select count
distinct sal from emp e2 where e1.sal <=e2.sal);
2) select empno,enaame,sal,deptno,rank () over (order by sal
desc) as ra from emp where ra=&n;
3) select empno,enaame,sal,deptno,dense_rank () over (order
by sal desc) as ra from emp where ra=&n;
All the above methods are tried n tested....it works
successfully.
What is a Cursor.
When a query is executed in oracle, a result set is produced
and stored in the memory. Oracle allows the programmer to
access this result set in the memory through cursors.
Why use a cursor?
Many times, when a query returns more than one row as a
result, we might want to go through each row and process the
data in different way for them. Cursor is handy here.
Types of cursors:
Oracle PL/SQL declares a cursor implicitly for all queries
and DML statements (including queries that return only one
row). But in most of the cases we don’t use these cursors
for queries that return one row. Based on this, there are 2
types of cursors
1. Explicit cursor
2. Implicit cursor
| Is This Answer Correct ? | 13 Yes | 2 No |
Post New Answer View All Answers
Differentiate between source qualifier and filter transformation?
How to differentiate between the active and passive transformations?
What is rank transformation in informatica
Design a mapping to get the pervious row salary for the current row. If there is no pervious row exists for the current row, then the pervious row salary should be displayed as null.
Different circumstance which drives informatica server to expel records?
What is the meaning of decode in informatica?
What is the difference between source qualifier transformations source filter to filter transformation?
differences between service based and product based?
What is aggregator transformation in informatica?
How can you increase the performance in joiner transformation?
hi real timers . iam waiting for ur reply regarding ETL TESTING
During the running session, output files are created by informatica server. Enlist few of them.
What are batches?
Suppose we do not group by on any ports of the aggregator what will be the output?
What are the limitations of joiner transformation?