SQL Comments

Getting Started with SQL Server

About Lesson

SQL Comments

In SQL, comments are used to annotate SQL code for better understanding and documentation. Comments are ignored by the SQL engine during execution.

Single-line Comments

SELECT * FROM Employees; -- This is a single-line comment

This is a single-line comment that follows a SQL statement.

/*
This is a multi-line comment
that spans across multiple lines
*/

This is a multi-line comment enclosed within /* and */ delimiters.

SELECT
    /* Selecting all columns */
    * 
FROM
    Employees;

This example demonstrates a comment within a SQL statement, providing additional context about the query.

Comments in SQL are essential for documenting code, explaining logic, and improving readability.
Single-line comments start with --, and multi-line comments are enclosed within /* and */ delimiters.
Comments should be concise and relevant to the code they annotate.
Comments are ignored by the SQL engine during execution, so they do not affect query performance.