Explaining the Difference between Function and Procedure in Oracle PL/SQL

When it comes to Oracle PL/SQL, understanding the difference between a function and a procedure is crucial. The main distinction lies in their return type and usage within a database application.

Function in Oracle PL/SQL

A function in Oracle PL/SQL is a named PL/SQL block that performs a specific task and returns a value. Functions are typically used to compute and return a single value based on the input parameters.

Example Usage of Function:

```sql
CREATE OR REPLACE FUNCTION calculate_total_price (item_price IN NUMBER, quantity IN NUMBER)
RETURN NUMBER
IS
BEGIN
RETURN item_price * quantity;
END;
```

In this example, the function `calculate_total_price` takes the `item_price` and `quantity` as input parameters and returns the total price by multiplying the item price with the quantity.

Procedure in Oracle PL/SQL

On the other hand, a procedure in Oracle PL/SQL is a named PL/SQL block that performs a specific task without returning a value. Procedures are commonly used to execute a series of SQL statements or tasks.

Example Usage of Procedure:

```sql
CREATE OR REPLACE PROCEDURE insert_order (order_id IN NUMBER, customer_id IN NUMBER, order_date IN DATE)
IS
BEGIN
INSERT INTO orders VALUES (order_id, customer_id, order_date);
COMMIT;
END;
```

In this example, the procedure `insert_order` is used to insert a new order into the `orders` table with the specified `order_id`, `customer_id`, and `order_date`.

When to Use Functions and Procedures in a Database Application

Functions are often preferred when you need to calculate and return a value, such as performing mathematical operations or data transformations. On the other hand, procedures are suitable for executing sequences of SQL statements or performing tasks that do not require a return value, such as data manipulation or validations.

Therefore, understanding the distinction between functions and procedures in Oracle PL/SQL is essential for designing efficient and effective database applications.