SQL Comments

As is any programming languages comments matter a lot in SQL also. In this set we will learn about writing comments in any SQL snippet.

Comments can be written in the following three formats:

• Single line comments.
• Multi line comments
• In line comments

Singleline comments: Comments starting and ending in a single line are considered as single line comments.

Line starting with ‘–‘ is a comment and will not be executed.

Syntax:

      -- single line comment

      -- another comment

SELECT * FROM Customers; 

Multiline comments: Comments starting in one line and ending in different line are considered as multi line comments. Line starting with ‘/*’ is considered as starting point of comment and are terminated when ‘*/’ is encountered.

Syntax:

/* multi line comment

another comment */

SELECT * FROM Customers; 

In line comments: In line comments are an extension of multi line comments, comments can be stated in between the statements and are enclosed in between ‘/*’ and ‘*/’.

Syntax:

SELECT * FROM /* Customers; */ 

More examples:

Multiine Comment :

/* SELECT * FROM Students;

SELECT * FROM STUDENT_DETAILS;

SELECT * FROM Orders; */

SELECT * FROM Articles; 

Inline Comment ->

SELECT * FROM Students;

SELECT * FROM /* STUDENT_DETAILS;

SELECT * FROM Orders;

SELECT * FROM */ Articles;