img img
The Menu of this blog is loading..........

PL/SQL First Program: Hello World Example

Dailyblogs1234

 

How to write a simple program using PL/SQL

In this section, we are going to write a simple program for printing “Hello World” using “Anonymous block“.

Write a simple program using PL/SQL

BEGIN
dbms_output.put_line (‘Hello World..');
END;
/

Output:

Hello World...

Code Explanation:

  • Code line 2: Prints the message “Hello World. . .”
  • The below screenshot explains how to enter the code in SQL* Plus.

Note: A block should be always followed by ‘/’ which sends the information to the compiler about the end of the block. Till the compiler encounters ‘/’, it will not consider the block is completed, and it will not execute it.

Write a simple program using PL/SQL

Declaring and usage of variables in the program

Here we are going to print the “Hello World” using the variables.

Declaring and usage of Variables

DECLARE
text VARCHAR2(25);
BEGIN
text:= ‘Hello World’;
dbms_output.put_line (text);
END:
/

Output:

Hello World

Code Explanation:

  • Code line 2: Declaring a variable “text” of a VARCHAR2 type with size 25
  • Code line 4: Assigning the value “Hello World” to the variable “text”.
  • Code line 5: Printing the value of the variable “text”.

Comments in PL/SQL

Commenting code simply instructs the compiler to ignore that particular code from executing.

Comment can be used in the program to increase the readability of the program. In PL/SQL codes can be commented in two ways.

  • Using ‘–‘ in the beginning of the line to comment that particular line.
  • Using ‘/*…….*/’ we can use multiple lines. The symbol ‘/*’ marks the starting of the comment and the symbol ‘*/’ marks the end of the comment. The code between these two symbols will be treated as comments by the compiler.

Example: In this example, we are going to print ‘Hello World’ and we are also going to see how the commented lines behave in the code

Comments in PL/SQL

BEGIN
--single line comment
dbms output.put line (' Hello World ’);
/*Multi line commenting begins
Multi line commenting ends */
END;
/

Output:

Hello World

Code Explanation:

  • Code line 2: Single line comment and compiler ignored this line from execution.
  • Code line 3: Printing the value “Hello World.”
  • Code line 4: Multiline commenting starts with ‘/*’
  • Code line 5: Multiline commenting ends with ‘*/’
Dailyblogs1234

Posted by Dailyblogs1234