Sum Of Two Numbers in PL/SQL

Prerequisite - PL/SQL introduction
In PL/SQL code groups of commands are arranged within a block. A block group related declarations or statements. 

In declare part, we declare variables and between begin and end part, we perform the operations.

Here, first, we take three variables x, y, and z and assign the value in x and y and after addition of both the numbers, we assign the resultant value to z and print z.

Examples:  

Input : 15 25
Output : 40

Input : 250 400
Output : 650

Below is the required implementation: 

Method 1:

declare

-- declare variable x, y 
-- and z of datatype number
x number(5);             
y number(5);            
z number(7);        

begin

-- Here we Assigning 10 into x
x:=10;                 

-- Assigning 20 into x
y:=20;                 

-- Assigning sum of x and y into z
z:=x+y;                 

-- Print the Result
dbms_output.put_line('Sum is '||z); 
end; 
/                         
-- Program End

Output : 

Sum is 30

Method 2(Using function) :

Here we are giving input during run time:

CREATE OR REPLACE FUNCTION add_two_nums(
    num1 NUMERIC,
    num2 NUMERIC
)
RETURNS NUMERIC AS $$
BEGIN
    RETURN num1 + num2;
END;
$$ LANGUAGE PLPGSQL;

In this method, we've created a PL/pgSQL function named 'add_two_nums' that takes two 'NUMERIC' parameters ('num1' and 'num2') and returns their sum. You can use the function like this:

postgres=# SELECT add_two_nums(5,6);

Output:

11