Comments

SQL comments

Comments is used to add a line which is not executed in the output.

Single line Comments

It starts with - -

Example:

- - Select all the employee

SELECT * FROM employee;

Example:

SELECT * FROM employee - - WHERE salary = 50,000 ;

In this example, the details of all the employee will be generated , not the salary. Here the salary is commented.

Multi-line comments

Multiple line comments starts with / * */ .

Any thing you write between the commented line it will not be considered ( ignored ).

Example:

/ * This will not be considered * /

Example:

/ * SELECT * FROM employee ;

SELECT * FROM student ; * /

SELECT * FROM library ;

In this example, employee and student is commented, so details of library will be generated or fetched.