how to make a loop for all columns of a table? - oracle

Question

I have a table EMPLOYEES, i need to make a loop, on every step of the loop I use dbms_output.put_line(column_name)
How can I make this?

Answer 1

Just found this solution
begin
for rec in (SELECT column_name
FROM all_tab_columns
WHERE owner = 'HR'
AND table_name = 'EMPLOYEES')
loop
dbms_output.put_line(rec.column_name);
end loop;
end;

Answer 2

Try to use cursor as below:
set serveroutput on;
declare
var_col1 varchar2(30) ;
num_col2 number ;
CURSOR cur
is
select var_col ,num_col
from table
where <conditions>;
begin
open cur;
fetch cur into var_col1,num_col2;
LOOP
fetch cur into var_col1,num_col2;
EXIT WHEN cur%NOTFOUND;
dbms_output.put_line( var_col1||' '||num_col2);
END LOOP;
close cur;
end;
here is another solution:
set serveroutput on;
begin
FOR cur in ( select var_col ,num_col from table where <conditions>)
LOOP
dbms_output.put_line(cur.var_col||' = '||cur.num_col);
END LOOP;
end;

Answer 3

Of course You can rewrite this SELECT example with WHERE after table_name. I dont compiled this code but I thinks its OK. Change ID_Employee and Name for your atributes
CREATE OR REPLACE PROCEDURE AAA_TEST
IS
BEGIN
DECLARE
v_id NUMBER :=0;
v_name VARCHAR2(25);
CURSOR cursorMails IS
SELECT Id_Employee,Name FROM EMPLOYEES;
BEGIN
OPEN cursorMails;
LOOP
FETCH cursorMails INTO v_id, v_name;
DBMS_OUTPUT.PUT_LINE('Number of Employee: ' || v_id || ' Name Employee: ' || v_name);
EXIT WHEN cursorMails%NOTFOUND;
END LOOP;
CLOSE cursorMails;
END;
END;
/