What is the basic structure of PL/SQL?

by

PL/SQL uses BLOCK structure as its basic structure. Each PL/SQL program consists of SQL and PL/SQL statement which form a PL/SQL block.

PL/SQL block contains 3 sections.

  • The Declaration Section (optional)
  • The Execution Section (mandatory)
  • The Exception handling Section (optional)

The basic structure of a PL/SQL (Procedural Language/Structured Query Language) block consists of three sections:

  1. Declaration Section: This is where you declare variables, constants, and cursors that will be used in the block. It starts with the keyword DECLARE and ends with the keyword BEGIN.
  2. Execution Section: This is where you write the actual PL/SQL code or logic. It starts with the keyword BEGIN and ends with the keyword END.
  3. Exception Section: This section handles exceptions (errors) that may occur during the execution of the block. It starts with the keyword EXCEPTION and ends with the keyword END.

Here is a simple example:

DECLARE
-- Declaration Section
v_variable NUMBER := 10;BEGIN
— Execution Section
DBMS_OUTPUT.PUT_LINE(‘The value of v_variable is: ‘ || v_variable);

— Exception Section
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE(‘An error occurred: ‘ || SQLERRM);
END;

In this example, DECLARE declares a variable v_variable, BEGIN contains the PL/SQL code, and EXCEPTION handles any exceptions that might occur. The / at the end is a delimiter indicating the end of the PL/SQL block.