56/125 Oracle PLSQL: Working with Packages / Forward Declaration

Learn Oracle PLSQL EXAM 1Z0-144 --------------------------------------------------------------------- create or replace package proc_rules_calling is procedure print_emp_details (p_emp_id number); end; create or replace package body proc_rules_calling is function get_no_work_days (p_emp_id number) return number is v_hiredate date; begin select HIRE_DATE into v_hiredate from employees where EMPLOYEE_ID=p_emp_id; return round(sysdate-v_hiredate); end; procedure print_emp_details (p_emp_id number) is -- we will call the funcion from this procedure --so it should be defined above in order to invoke it v_details employees%rowtype; begin select * into v_details from employees where EMPLOYEE_ID=p_emp_id; dbms_output.put_line( 'id:'||v_details.EMPLOYEE_ID); dbms_output.put_line( 'fname:'||v_details.FIRST_NAME); dbms_output.put_line( 'salary:'||v_details.salary); dbms_output.put_line( 'hire date:'||v_details.HIRE_DATE); dbms_output.put_line( 'no of days work:'||get_no_work_days(p_emp_id)); end; end; execute proc_rules_calling.print_emp_details(101); ------------------------------------------------------------------------------ --same example but we will change the order create or replace package proc_rules_calling is procedure print_emp_details (p_emp_id number); end; --it will give error --'GET_NO_WORK_DAYS' not declared in this scope create or replace package body proc_rules_calling is procedure print_emp_details (p_emp_id number) is v_details employees%rowtype; begin select * into v_details from employees where EMPLOYEE_ID=p_emp_id; dbms_output.put_line( 'id:'||v_details.EMPLOYEE_ID); dbms_output.put_line( 'fname:'||v_details.FIRST_NAME); dbms_output.put_line( 'salary:'||v_details.salary); dbms_output.put_line( 'hire date:'||v_details.HIRE_DATE); dbms_output.put_line( 'no of days work:'||get_no_work_days(p_emp_id)); end; function get_no_work_days (p_emp_id number) return number is v_hiredate date; begin select HIRE_DATE into v_hiredate from employees where EMPLOYEE_ID=p_emp_id; return round(sysdate-v_hiredate); end; end; ------------------------------------------------------------------ --the solution is to do forward declaration drop package proc_rules_calling; create or replace package proc_rules_calling is procedure print_emp_details (p_emp_id number); end; create or replace package body proc_rules_calling is function get_no_work_days (p_emp_id number) return number; -- we put the function specification only procedure print_emp_details (p_emp_id number) is -- we will call the funcion from this procedure --so it should be defined above in order to invoke it v_details employees%rowtype; begin select * into v_details from employees where EMPLOYEE_ID=p_emp_id; dbms_output.put_line( 'id:'||v_details.EMPLOYEE_ID); dbms_output.put_line( 'fname:'||v_details.FIRST_NAME); dbms_output.put_line( 'salary:'||v_details.salary); dbms_output.put_line( 'hire date:'||v_details.HIRE_DATE); dbms_output.put_line( 'no of days work:'||get_no_work_days(p_emp_id)); end; function get_no_work_days (p_emp_id number) return number is v_hiredate date; begin select HIRE_DATE into v_hiredate from employees where EMPLOYEE_ID=p_emp_id; return round(sysdate-v_hiredate); end; end; execute proc_rules_calling.print_emp_details(104);