PL/SQL Comments

Last Updated : 16 May, 2026

PL/SQL provides comments to make code more readable and understandable. Comments are non-executable statements ignored by the compiler during execution.

  • Improve code readability and understanding.
  • Help explain complex queries and logic.
  • They are ignored during program execution.
  • Provide context and documentation for database code.

Types of PL/SQL Comments

Comments in PL/SQL are explanatory statements used to improve the readability and understanding of the code. It supports two main types of comments.

commentsin-plsql
Types of PL/SQL Comments

1. Single-Line Comments

A single-line comment in PL/SQL starts with --. Everything written after it on the same line is treated as a comment and ignored by the compiler. It is used for short explanations or notes in the code.

Syntax

-- This is a single line comment

Example: PL/SQL Program to illustrate Single-Line Comment

DECLARE
   a NUMBER := 10;   -- First number
   b NUMBER := 20;   -- Second number
   c NUMBER;         -- Variable to store sum
BEGIN
   c := a + b;       -- Adding two numbers
   DBMS_OUTPUT.PUT_LINE(c);   -- Display result
END;
/

2. Multi-Line Comments

Multi-line comments in PL/SQL are used to comment multiple lines together. They start with /* and end with */. They are useful for writing detailed explanations in the code.

Syntax 

/* Multi line comment starts
. . .  continue . . .
. . .  continue . . .
. . .  continue . . .
Multi line comment ends */

Example: PL/SQL Program to illustrate the Multi-Line Comment

DECLARE
   a NUMBER := 10;
   b NUMBER := 20;
   c NUMBER;

BEGIN
   /* Adding the values
      of a and b */
   c := a + b;

   DBMS_OUTPUT.PUT_LINE(c);
END;
/

Importance of Comments in PL/SQL

  • Comments make the code more readable and easier to understand for programmers.
  • They help during debugging by explaining the logic and flow of the program.
  • Comments are useful for documenting variables, functions and important statements in the code.
  • They can be used to mark future changes or improvements needed in the program.
  • Comments help other developers understand and maintain the code more easily.
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