ORDER BY with ASC and DESC in SQL

Introduction

We use ORDER BY to sort data in a table. ASC sorts from smallest to largest, DESC sorts from largest to smallest.

When you want to see a list of products sorted by price from low to high.

When you want to find the top scoring students by sorting scores from high to low.

When you want to organize a list of names alphabetically.

When you want to see recent orders first by sorting dates from newest to oldest.

Syntax

SQL

SELECT column1, column2
FROM table_name
ORDER BY column1 ASC | DESC;

ASC means ascending order (smallest to largest).

DESC means descending order (largest to smallest).

Examples

This sorts people by age from youngest to oldest.

SQL

SELECT name, age
FROM people
ORDER BY age ASC;

This sorts products by price from highest to lowest.

SQL

SELECT product, price
FROM products
ORDER BY price DESC;

This sorts cities alphabetically by name.

SQL

SELECT city, population
FROM cities
ORDER BY city ASC;

Sample Program

This creates a table of employees and sorts them by salary from highest to lowest.

SQL

CREATE TABLE employees (id INT, name VARCHAR(20), salary INT);
INSERT INTO employees VALUES
(1, 'Alice', 5000),
(2, 'Bob', 7000),
(3, 'Charlie', 6000);

SELECT name, salary
FROM employees
ORDER BY salary DESC;

Important Notes

If you do not specify ASC or DESC, ASC is the default.

You can order by multiple columns by separating them with commas.

Summary

ORDER BY sorts query results.

Use ASC for ascending order, DESC for descending order.

Sorting helps you organize data to find what you need quickly.

Practice

1. What does the ORDER BY clause do in an SQL query?

easy

A. It sorts the query results in a specified order.

B. It filters rows based on a condition.

C. It groups rows with the same values.

D. It limits the number of rows returned.

Solution

1. Step 1: Understand the purpose of ORDER BY

   The ORDER BY clause is used to arrange the rows returned by a query in a specific order.

2. Step 2: Differentiate from other clauses

   Filtering is done by WHERE, grouping by GROUP BY, and limiting rows by LIMIT. Only ORDER BY sorts the results.

3. Final Answer:

   It sorts the query results in a specified order. -> Option A

4. Quick Check:

   ORDER BY = sorts results [OK]

Hint: ORDER BY always sorts rows; remember ASC or DESC [OK]

Common Mistakes:

• Confusing ORDER BY with WHERE clause
• Thinking ORDER BY filters rows
• Mixing ORDER BY with GROUP BY

2. Which of the following is the correct syntax to sort a table named Employees by the column Salary in descending order?

easy

A. SELECT * FROM Employees ORDER BY Salary DESC;

B. SELECT * FROM Employees SORT BY Salary DESC;

C. SELECT * FROM Employees ORDER Salary DESC;

D. SELECT * FROM Employees ORDER BY Salary DOWN;

Solution

1. Step 1: Recall correct ORDER BY syntax

   The correct syntax to sort is ORDER BY column_name ASC|DESC. Here, DESC means descending order.

2. Step 2: Check each option

   SELECT * FROM Employees ORDER BY Salary DESC; uses correct keywords and syntax. Options B, C, and D use invalid keywords like SORT BY, missing BY, or incorrect direction word.

3. Final Answer:

   SELECT * FROM Employees ORDER BY Salary DESC; -> Option A

4. Quick Check:

   ORDER BY + DESC = correct syntax [OK]

Hint: ORDER BY must be followed by column and ASC or DESC [OK]

Common Mistakes:

• Using SORT BY instead of ORDER BY
• Omitting BY after ORDER
• Using DOWN instead of DESC

3. Given the table Products with columns ProductID and Price, what will be the order of ProductID after running this query?

SELECT ProductID FROM Products ORDER BY Price ASC;

medium

A. Products sorted by ProductID descending.

B. Products sorted by Price from highest to lowest.

C. Products sorted by ProductID ascending.

D. Products sorted by Price from lowest to highest.

Solution

1. Step 1: Analyze ORDER BY clause

   The query orders rows by Price in ascending order, meaning from smallest to largest price.

2. Step 2: Understand output column

   The query selects ProductID but orders by Price. So the ProductID values will appear sorted according to their prices ascending.

3. Final Answer:

   Products sorted by Price from lowest to highest. -> Option D

4. Quick Check:

   ORDER BY Price ASC = lowest to highest [OK]

Hint: ORDER BY sorts by specified column, not selected column [OK]

Common Mistakes:

• Assuming sorting is by selected column instead of ORDER BY column
• Confusing ASC with DESC
• Thinking ORDER BY changes selected columns

4. Identify the error in this SQL query:

SELECT Name FROM Customers ORDER BY Age DESCENDING;

medium

A. Missing ASC keyword after ORDER BY.

B. The keyword DESCENDING is invalid; use DESC instead.

C. ORDER BY cannot be used with DESC.

D. The column Age does not exist.

Solution

1. Step 1: Check ORDER BY direction keywords

   SQL uses ASC for ascending and DESC for descending order. DESCENDING is not a valid keyword.

2. Step 2: Validate other parts

   ORDER BY works with DESC. ASC is optional. We assume Age exists as no schema given.

3. Final Answer:

   The keyword DESCENDING is invalid; use DESC instead. -> Option B

4. Quick Check:

   Use DESC, not DESCENDING [OK]

Hint: Use DESC, not DESCENDING for descending order [OK]

Common Mistakes:

• Typing DESCENDING instead of DESC
• Thinking DESC is not allowed
• Assuming ASC is mandatory

5. You have a table Students with columns Name, Grade, and Age. You want to list students sorted first by Grade descending (highest grade first), and then by Age ascending (youngest first) within the same grade. Which query achieves this?

hard

A. SELECT * FROM Students ORDER BY Age DESC, Grade ASC;

B. SELECT * FROM Students ORDER BY Grade ASC, Age DESC;

C. SELECT * FROM Students ORDER BY Grade DESC, Age ASC;

D. SELECT * FROM Students ORDER BY Age ASC, Grade DESC;

Solution

1. Step 1: Understand sorting priorities

   We want to sort by Grade descending first, so highest grades come first.

2. Step 2: Apply secondary sorting

   Within the same grade, sort by Age ascending, so younger students appear first.

3. Step 3: Match query syntax

   SELECT * FROM Students ORDER BY Grade DESC, Age ASC; matches the required order: ORDER BY Grade DESC, Age ASC. Other options reverse order or directions.

4. Final Answer:

   SELECT * FROM Students ORDER BY Grade DESC, Age ASC; -> Option C

5. Quick Check:

   ORDER BY Grade DESC, Age ASC = correct multi-level sort [OK]

Hint: List columns in ORDER BY by priority with ASC or DESC [OK]

Common Mistakes:

• Reversing ASC and DESC directions
• Swapping column order in ORDER BY
• Using only one column for sorting