Why we can't execute stored procedure in select statement in oracle? is there any strong reason?

Question

create or replace procedure pr
is
    v_date date; 
begin
    select sysdate into v_date from dual;
    DBMS_output.put_line(v_date);
end pr;

Answer 1

Procedure cannot be executed using select statement, you can use function if you would want to execute using select statement.

If you would want to execute procedure using select statement then one approach is wrap your procedure with a function and call function using select statement.

CREATE OR REPLACE PROCEDURE pr (o_param OUT DATE)
IS
    v_date  DATE;
BEGIN
    SELECT  SYSDATE
      INTO  v_date
      FROM  DUAL;

    o_param := v_date;
END pr;

Now wrap the procedure with a function

CREATE OR REPLACE FUNCTION my_funct
    RETURN DATE
AS
    o_param  DATE;
BEGIN
    pr (o_param);

    RETURN o_param;
EXCEPTION
    WHEN NO_DATA_FOUND
    THEN
        DBMS_OUTPUT.put_line (
        DBMS_UTILITY.format_error_backtrace || ' ' || SQLERRM
    );
                -- raise exception 
    WHEN OTHERS
    THEN
        DBMS_OUTPUT.put_line (
        DBMS_UTILITY.format_error_backtrace || ' ' || SQLERRM
    );
                -- raise exception  
END my_funct;
/

And call the function using select statement

SELECT my_funct  FROM DUAL