How to Get the Top 5 Highest Values from an Oracle SQL Column?
Jan 09, 2025 pm 01:42 PMOracle SQL: How to retrieve the top 5 highest values in a column
In database queries, it is often necessary to limit the results to rows with specific characteristics, such as the highest or lowest value in a specific column. In Oracle SQL, you can use analytic functions such as RANK(), DENSE_RANK(), or ROW_NUMBER() for this purpose.
RANK() and DENSE_RANK() for highest values
Analysis functions like RANK() and DENSE_RANK() assign a rank to each row based on a specified ranking. To retrieve the top 5 highest values in a column, you can use the following query format:
SELECT * FROM ( SELECT <column_name>, RANK() OVER (ORDER BY <column_name> DESC) AS rnk FROM <table_name> ) WHERE rnk <= 5;
RANK() assigns a numerical rank to each row, starting with the highest value of 1. DENSE_RANK() compresses gaps when identical values exist, while assigning ranks.
ROW_NUMBER() for a specific number of rows
ROW_NUMBER() analysis function assigns a serial number to each row. You can use this to retrieve a specific number of rows regardless of their value. For example:
SELECT * FROM ( SELECT <column_name>, ROW_NUMBER() OVER (ORDER BY <column_name> DESC) AS rnk FROM <table_name> ) WHERE rnk <= 5;
Non-analytical solution: use ROWNUM
Although less common, you can also use the ROWNUM pseudo-column to limit the results to a specific number of rows. However, it should be used with caution because ROWNUM is evaluated before the ORDER BY clause, which can lead to unpredictable results.
Example: Get the highest paid employee
To illustrate the use of RANK() and DENSE_RANK() when retrieving the 5 highest paid employees:
SELECT * FROM ( SELECT empno, sal, RANK() OVER (ORDER BY sal DESC) AS rnk FROM emp ) WHERE rnk <= 5;
This query assigns each employee a numerical rank based on their salary, where 1 represents the highest paid employee. It then displays the top 5 employees in order of decreasing salary.
The above is the detailed content of How to Get the Top 5 Highest Values from an Oracle SQL Column?. For more information, please follow other related articles on the PHP Chinese website!

Hot Article

Hot tools Tags

Hot Article

Hot Article Tags

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics

Reduce the use of MySQL memory in Docker

How do you alter a table in MySQL using the ALTER TABLE statement?

How to solve the problem of mysql cannot open shared library

What is SQLite? Comprehensive overview

Run MySQl in Linux (with/without podman container with phpmyadmin)

Running multiple MySQL versions on MacOS: A step-by-step guide

What are some popular MySQL GUI tools (e.g., MySQL Workbench, phpMyAdmin)?

How do I configure SSL/TLS encryption for MySQL connections?
