Oracle PL/SQL - Basic Terms

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Term	Explanation
PL/SQL	Procedural Language extension of SQL used in Oracle databases. It adds procedural features like variables, loops, and conditions to SQL.
Block	The basic unit of a PL/SQL program. Every PL/SQL code is written in blocks (anonymous or named).
DECLARE	Section to declare variables, constants, cursors, and exceptions (optional).
BEGIN	Mandatory section where the actual executable code (SQL & PL/SQL statements) is written.
EXCEPTION	Optional section to handle runtime errors (exceptions).
END	Marks the end of the PL/SQL block.
Variable	A placeholder to store data temporarily during program execution.
Constant	A variable whose value cannot be changed once initialized.
Cursor	Used to retrieve multiple rows from a SELECT query, row-by-row.
Loop	Allows repeated execution of a block of code.
IF-THEN-ELSE	Conditional statement to perform different actions based on conditions.
Procedure	A named PL/SQL block that performs a task.
Function	Similar to a procedure, but it returns a value.
Trigger	A PL/SQL block that executes automatically in response to an event (e.g., insert, update).
Exception	Error condition during execution (e.g., NO_DATA_FOUND, TOO_MANY_ROWS).

Basic syntax:


DECLARE
-- Variable declarations
variable_name datatype;
BEGIN
-- Executable statements
-- SQL and PL/SQL code goes here
DBMS_OUTPUT.PUT_LINE('Hello PL/SQL!');
EXCEPTION
-- Exception handling
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('An error occurred.');
END;
/

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