---
title: "Explain the usage of the CASE statement in SQL for conditional expressions."  
description: "Explain the usage of the CASE statement in SQL for conditional expressions."  
author: "Revati S Misra"  
published: 2023-07-04  
updated: 2023-07-05  
canonical: https://www.mindstick.com/forum/158948/explain-the-usage-of-the-case-statement-in-sql-for-conditional-expressions  
category: "mssql server"  
tags: ["mssql server", "sql server", "sql"]  
reading_time: 3 minutes  

---

# Explain the usage of the CASE statement in SQL for conditional expressions.

[Explain the usage](https://www.mindstick.com/forum/158941/explain-the-usage-and-difference-between-the-and-and-or-operators-in-sql) of the CASE [statement in SQL](https://www.mindstick.com/forum/33706/what-is-the-difference-between-having-clause-and-group-by-statement-in-sql-server) for conditional expressions.

## Replies

### Reply by Aryan Kumar

Sure. The [CASE statement](https://www.mindstick.com/blog/290/case-statement-in-sql-server) in [SQL](https://www.mindstick.com/articles/13115/types-of-keys-in-sql-or-oracle-database) is a conditional statement that allows you to evaluate a condition and return a different value depending on the result of the evaluation. The CASE statement can be used to perform a variety of tasks, such as:

- Formatting data based on different conditions.
- Calculating different values for different groups of data.
- Determining the next action to take based on the results of a logical expression.

The CASE statement has the following syntax:

SQL

```plaintext
CASE WHEN condition1 THEN value1
WHEN condition2 THEN value2
[ELSE valueN]
END;
```

The `condition1` is the first condition that will be evaluated. If the condition is true, then the `value1` will be returned. If the condition is false, then the `condition2` will be evaluated. If the `condition2` is true, then the `value2` will be returned. This process will continue until one of the conditions is true, or until the `ELSE` clause is reached. If the `ELSE` clause is reached, then the `valueN` will be returned.

The `valueN` can be any expression, including a literal value, a column name, or a function call. The `valueN` can also be a nested CASE statement.

Here is an example of how the CASE statement can be used to format data based on different conditions:

SQL

```plaintext
SELECT customer_name,
CASE
WHEN status = 'Active' THEN 'Active'
WHEN status = 'Inactive' THEN 'Inactive'
ELSE 'Unknown'
END AS status
FROM customers;
```

This query will select the `customer_name` and `status` columns from the `customers` table. The `CASE` statement will be used to format the `status` column based on the value of the `status` column. If the value of the `status` column is `Active`, then the `CASE` statement will return the value `Active`. If the value of the `status` column is `Inactive`, then the `CASE` statement will return the value `Inactive`. If the value of the `status` column is not `Active` or `Inactive`, then the `CASE` statement will return the value `Unknown`.

Here is an example of how the CASE statement can be used to calculate different values for different groups of data:

SQL

```plaintext
SELECT department,
CASE
WHEN department = 'Sales' THEN salary * 1.1
WHEN department = 'Marketing' THEN salary * 1.2
ELSE salary
END AS bonus
FROM employees;
```

This query will select the `department` and `bonus` columns from the `employees` table. The `CASE` statement will be used to calculate the `bonus` column based on the value of the `department` column. If the value of the `department` column is `Sales`, then the `CASE` statement will return the value of the `salary` column multiplied by 1.1. If the value of the `department` column is `Marketing`, then the `CASE` statement will return the value of the `salary` column multiplied by 1.2. If the value of the `department` column is not `Sales` or `Marketing`, then the `CASE` statement will return the value of the `salary` column.

The CASE statement is a powerful tool that can be used to perform a variety of tasks in SQL. It is a versatile statement that can be used in a variety of ways to analyze data.


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Original Source: https://www.mindstick.com/forum/158948/explain-the-usage-of-the-case-statement-in-sql-for-conditional-expressions

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