Using string as colum name in query

Question

here i am using " lc_remarks " for a colum name , it is changed according to previous conditions,
in below code it is used as a string , how can i use it as a column name
BEGIN
lc_remarks := ' left_date ';
Select student_id into ln_temp_student from std_temp_tut_ledger
where lc_remarks is null;
EXCEPTION
WHEN NO_DATA_FOUND THEN
ln_temp_student := 0;
DBMS_OUTPUT.PUT_LINE( ' insert record here ' || f_name(i) );
When TOO_MANY_ROWS THEN
ln_temp_student := 2;
END;
i also triend this one
BEGIN
lc_remarks := ' where left_date is null';
Select student_id into ln_temp_student from std_temp_tut_ledger
lc_remarks;
EXCEPTION
WHEN NO_DATA_FOUND THEN
ln_temp_student := 0;
DBMS_OUTPUT.PUT_LINE( ' insert record here ' || f_name(i) );
When TOO_MANY_ROWS THEN
ln_temp_student := 2;
END;
but looked like it does not processed " lc_remarks " in query

Answer 1

Taken from
http://www.databasejournal.com/features/oracle/article.php/2109681
To retrieve values from a dynamic statement (INTO clause).
declare
l_cnt varchar2(20);
begin
execute immediate 'select count(1) from emp'
into l_cnt;
dbms_output.put_line(l_cnt);
end;