How to Call Function In Oracle?

To call a function in Oracle, you need to use the syntax:

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SELECT function_name(arguments) FROM dual;

In this syntax, replace "function_name" with the name of the function you want to call and "arguments" with any input parameters the function requires. The "FROM dual" clause is used to call the function without referencing an actual table.

You can also call a function within a SQL statement by using it as an expression:

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SELECT column1, function_name(column2) FROM table_name;

In this case, the function will be called for each row returned by the query, using the value of "column2" as input.

Make sure to correctly specify the function name and input parameters when calling a function in Oracle.

How to execute a function in Oracle SQL Developer?

To execute a function in Oracle SQL Developer, you can simply use a SQL query to call the function. Here's an example:

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SELECT my_function(parameter1, parameter2) FROM dual;

Replace my_function with the name of the function you want to execute, and parameter1, parameter2, etc. with the actual parameters required by the function.

After you have written your query, you can execute it by clicking on the "Run" button in SQL Developer, or by pressing the F9 key on your keyboard. The output of the function will be displayed in the results pane.

What is the difference between calling a function and a procedure in Oracle?

In Oracle, the main difference between calling a function and a procedure lies in their return types and how they are executed.

1. Function:

• A function in Oracle is a named program unit that returns a value. It is defined using the CREATE FUNCTION statement.
• Functions can be called within SQL statements to perform a computation and return a result.
• Functions must return a value using the RETURN statement.
• Functions can be called from SQL statements, PL/SQL blocks, and other functions.
• Functions can be used in SELECT, WHERE, and other query clauses.
• Example: SELECT my_function(param1, param2) FROM dual;

1. Procedure:

• A procedure in Oracle is a named program unit that performs a specific task or set of tasks. It is defined using the CREATE PROCEDURE statement.
• Procedures do not return any value; they are used to perform operations or tasks.
• Procedures can have both input and output parameters but do not have a return statement.
• Procedures are executed explicitly by calling them from PL/SQL blocks or other procedures.
• Procedures cannot be used in SQL statements directly.
• Example: EXECUTE my_procedure(param1, param2);

In summary, the main difference between a function and a procedure in Oracle is the return type and how they are called and used in PL/SQL and SQL statements. Functions return a value and can be used in SQL statements, while procedures do not return any value and are used to perform operations or tasks.

How to call a function in a package in Oracle?

To call a function in a package in Oracle, you can use the following syntax:

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package_name.function_name(parameters);

For example, if you have a package named my_package with a function named calculate_salary that takes an employee id as a parameter, you can call the function like this:

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DECLARE
    salary NUMBER;
BEGIN
    salary := my_package.calculate_salary(1001);
    DBMS_OUTPUT.PUT_LINE('Salary for employee 1001: ' || salary);
END;

Make sure to replace package_name and function_name with the actual names of your package and function. You also need to ensure that the package has been created and compiled in the database before you can call its functions.