oracle stored procedure with parameters

Oracle is a widely used relational database management system. In Oracle, a stored procedure is a set of preprocessed SQL statements that are stored together and called and executed by a single name. Stored procedures can be used to improve the performance and security of your database. When a stored procedure needs to receive parameters, we need to use a stored procedure with parameters.

A stored procedure with parameters is a special type of stored procedure that allows users to provide parameters to the stored procedure before executing it. These parameters may be numbers, strings, dates, etc. Parameterized stored procedures are very popular in Oracle databases because they provide a fast and highly reusable method to complete common data operations.

In Oracle, the syntax for using stored procedures with parameters is as follows:

CREATE [OR REPLACE] PROCEDURE procedure_name
(parameter_name [IN|OUT] data_type [, …])
IS
BEGIN
    /* Procedure Body */
END;

In this syntax, we can see three main elements:

• procedure_name: The name of the stored procedure. It can be any valid Oracle identifier.
• parameter_name: The parameter name in the stored procedure. It can also be any valid Oracle identifier.
• data_type: The data type of the parameter.

In this syntax, we can also see the IN and OUT keywords, which are used to specify the direction of the parameters. IN means that the parameter is an input parameter, i.e. a value is provided to it when executing the stored procedure. OUT indicates that the parameter is an output parameter, that is, the value returned after the stored procedure is executed.

Next, let’s create a simple stored procedure with parameters, in which there are two input parameters representing two numbers, and then add them together and return the result.

CREATE OR REPLACE PROCEDURE add_two_numbers (num1 IN NUMBER, num2 IN NUMBER, result OUT NUMBER)
IS
BEGIN
    result := num1 + num2;
END;

In this example, we use three parameters: num1 and num2 are input parameters, and result is the output parameter. In the body of the stored procedure, we add num1 and num2 using the addition operator and assign the result to the result parameter.

Now, let’s call this stored procedure and see the output:

DECLARE
    num1 NUMBER := 10;
    num2 NUMBER := 20;
    res NUMBER;
BEGIN
    add_two_numbers(num1, num2, res);
    DBMS_OUTPUT.PUT_LINE('The sum of ' || num1 || ' and ' || num2 || ' is ' || res);
END;

In this code, we declare three variables: num1, num2 and res. We then use the add_two_numbers stored procedure to call these two variables and assign the result to the res variable. Finally, we use the DBMS_OUTPUT.PUT_LINE function to output the results to the terminal.

What needs to be noted here is that in the stored procedure call, we need to pass values ​​to the stored procedure in the order of its parameters.

To summarize: Stored procedures with parameters are a very useful and convenient function in the Oracle database management system. By using stored procedures with parameters, we can easily complete common data operations and improve the performance and security of the database system. To create a stored procedure with parameters, we need to specify the name of the stored procedure, the names and data types of the parameters. Also, in the stored procedure call, we need to pass values ​​to the stored procedure parameters in the order they are.

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