PL/SQL Variables

Variables can be any SQL data type such as CHAR, DATE, NUMBER or PL/SQL data type such as BOOLEAN or PLS_INTEGER.

Declare data type for variables in PL/SQL

You can use the special words %ROWTYPE or %TYPE to declare variables that keeps the columns of tables or records of the tables.
%TYPE attribute provides the ability to set the data type of a variable as being the same with the data type of a column from the table.
Example: v_last_name students.last_name% TYPE;
%ROWTYPE attribute offers a type of record that represents a row in a database table. Can store all rows from the table.

1. Declaring Variables in PL/SQL

DECLARE
student_id NUMBER;
first_name VARCHAR2(100);
is_graduate BOOLEAN;
birthday DATE;

2. Variable use example

DECLARE 
	var_number NUMBER:=40; 
	var_char VARCHAR2(250):='PL/SQL Tutorial'; 
	emp_rec employees%ROWTYPE; 
BEGIN 
	DBMS_OUTPUT.PUT_LINE(var_number); 
	DBMS_OUTPUT.PUT_LINE(var_char); 
	
	var_char:= UPPER(var_char); 
	DBMS_OUTPUT.PUT_LINE(var_char);  

	SELECT * INTO emp_rec from employees WHERE id = 1; 
	DBMS_OUTPUT.PUT_LINE(emp_rec.id);
	DBMS_OUTPUT.PUT_LINE(emp_rec.name);
END;