Multiple choice technology databases

Given a function CALCTAX : CREATE OR REPLACE FUNCTION calc tax (sal NUMBER) RETURN NUMBER IS BEGIN RETURN (sal * 0.05); END; If you want to run the above function from the SQL *Plus prompt, which statement is true?

  1. a) You need to execute the command CALCTAX(1000); .

  2. b) You need to execute the command EXECUTE FUNCTION calc tax; .

  3. c) You need to create a SQL *Plus environment variable X and issue the command :X := CALCTAX(1000); .

  4. d) You need to create a SQL *Plus environment variable X and issue the command EXECUTE :X := CALCTAX;

  5. e) You need to create a SQL *Plus environment variable X and issue the command EXECUTE :X := CALCTAX(1000);
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

To execute a PL/SQL function from SQL*Plus and capture its return value, you must create a bind variable and use the EXECUTE command with the variable assignment syntax (E). Option A is incorrect because you cannot call a function directly without handling the return value. Options B and D use incorrect syntax. Option C is missing the EXECUTE keyword required for anonymous blocks in SQL*Plus.

AI explanation

To run the given function CALCTAX from the SQL *Plus prompt, you need to create a SQL *Plus environment variable X and issue the command EXECUTE :X := CALCTAX(1000);.

Let's go through each option to understand why it is correct or incorrect:

Option A) You need to execute the command CALCTAX(1000); - This option is incorrect because executing the function directly without assigning the result to a variable will not give you the desired output.

Option B) You need to execute the command EXECUTE FUNCTION calc tax; - This option is incorrect because the syntax of the EXECUTE command is incorrect. It should be EXECUTE ();.

Option C) You need to create a SQL *Plus environment variable X and issue the command :X := CALCTAX(1000); - This option is incorrect because the syntax of assigning a value to the variable X is incorrect. It should be X := ; instead of :X := ;.

Option D) You need to create a SQL *Plus environment variable X and issue the command EXECUTE :X := CALCTAX; - This option is incorrect because the function CALCTAX requires an input argument sal, which is missing in the EXECUTE command.

Option E) You need to create a SQL *Plus environment variable X and issue the command EXECUTE :X := CALCTAX(1000); - This option is correct because it correctly creates a SQL *Plus environment variable X and assigns the result of the function CALCTAX(1000) to X using the EXECUTE command.

The correct answer is option E.

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