using cursor attributes in a CURSOR FOR LOOP - oracle

Question

I am running the following in the Scott schema:
SET serveroutput ON;
BEGIN
FOR c_Emp IN (SELECT * FROM emp)
LOOP
dbms_output.put_line('The record processed by the cursor ' || c_Emp%rowcount);
END LOOP;
end;
This gives the error:
cursor attribute may not be applied to non-cursor 'C_EMP'
However if this is done using an explicit cursor it works fine:
set serveroutput on ;
DECLARE
emp_record emp%ROWTYPE;
count_variable NUMBER;
CURSOR c IS
SELECT * FROM emp;
BEGIN
OPEN c;
loop
fetch c INTO emp_record;
exit WHEN c%notfound;
dbms_output.put_line ('The record count is ' || c%rowcount);
END loop;
close c;
end;
Just want to understand : whether while using the CURSOR FOR LOOP, is the index variable not a cursor attribute, if so why? could someone plz expalin this....

Answer 1

c_Emp is not the cursor, its a record with felds for each column in the SELECT statment
c_Emp is similar to the emp_record from your second example.

Answer 2

Even while using a FOR loop the cursor has to be explicitly defined.
A sample use of FOR loop with a cursor would look like below:
declare
cursor c1 is select a from table;
begin
FOR b in c1
loop
<required logic>
end loop;
end;

Answer 3

To get the index in a for loop, you can add the rownum pseudocolumn in the select clause of implicit cursor.
SET serveroutput ON;
BEGIN
FOR c_Emp IN (SELECT e.*, rownum FROM emp e)
LOOP
dbms_output.put_line('The record processed by the cursor ' || c_Emp.rownum);
END LOOP;
end;

Answer 4

Try this:
SET serveroutput ON;
DECLARE
x NUMBER :=0 ;
BEGIN
FOR c_Emp IN (SELECT * FROM emp)
LOOP
x := x+1;
dbms_output.put_line('The record processed by the cursor ' || x);
END LOOP;
-----
IF x>0 THEN
dbms_output.put_line('Cursr was opened');
ELSE
dbms_output.put_line('Cursr was not opened');
END IF;
end;

Answer 5

SQL> create table product(
2 product_id number(4) not null,
3 product_description varchar2(20) not null
4 );
Table created.
SQL>
SQL> insert into product values (1,'Java');
1 row created.
SQL> insert into product values (2,'Oracle');
1 row created.
SQL> insert into product values (3,'C#');
1 row created.
SQL> insert into product values (4,'Javascript');
1 row created.
SQL> insert into product values (5,'Python');
1 row created.
SQL> create table company(
2 product_id number(4) not null,
3 company_id NUMBER(8) not null,
4 company_short_name varchar2(30) not null,
5 company_long_name varchar2(60)
6 );
Table created.
SQL> insert into company values(1,1001,'A Inc.','Long Name A Inc.');
1 row created.
SQL> insert into company values(1,1002,'B Inc.','Long Name B Inc.');
1 row created.
SQL> insert into company values(1,1003,'C Inc.','Long Name C Inc.');
1 row created.
SQL> insert into company values(2,1004,'D Inc.','Long Name D Inc.');
1 row created.
SQL> insert into company values(2,1005,'E Inc.','Long Name E Inc.');
1 row created.
SQL> insert into company values(2,1006,'F Inc.','Long Name F Inc.');
1 row created.
SQL> DECLARE
2 CURSOR cursorValue IS
3 SELECT h.product_description,o.company_short_name FROM company o,product h
4 WHERE o.product_id =h.product_id
5 ORDER by 2;
6 num_total_rows NUMBER;
7 BEGIN
8
9 FOR idx IN cursorValue LOOP
10 dbms_output.put_line(rpad(idx.product_description,20,' ')||' '||
11 rpad(idx.company_short_name,30,' '));
12
13 num_total_rows :=cursorValue%ROWCOUNT;
14 END LOOP;
15 IF num_total_rows >0 THEN
16 dbms_output.new_line;
17 dbms_output.put_line('Total Organizations = '||to_char(num_total_rows));
18 END IF;
19 END;
20 /
Java A Inc.
Java B Inc.
Java C Inc.
Oracle D Inc.
Oracle E Inc.
Oracle F Inc.
Total Organizations = 6
PL/SQL procedure successfully completed.
SQL> drop table product;
Table dropped.
SQL> drop table company;
Table dropped.
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