PL/SQL Function to check whether a number is prime or not - sql

Question

Please find the error and rectify this code
This is a PL/SQL function to check whether a number is prime or not
By using the flag method instead of using count to check the requirement, it's working perfectly but not for this method.
create or replace function isprime(x in number)
RETURN number
IS
i int;
count int;
BEGIN
count:=0;
for i in 2..x/2 LOOP
if mod(x,i)=0 then
count:=count+1;
end if;
end loop;
return count;
end;
/
Warning: Function created with compilation errors.
DECLARE
n int;
c int;
BEGIN
n:=&n;
c:=isprime(n);
if c=0 then
dbms_output.put_line(n||'is a prime number');
else
dbms_output.put_line(n||'is not prime');
end if;
end;
/
Enter value for n: 5
old 5: n:=&n;
new 5: n:=5;
c:=isprime(n);
*
ERROR at line 6:
ORA-06550: line 6, column 4:
PLS-00905: object SYSTEM.ISPRIME is invalid
ORA-06550: line 6, column 1:
PL/SQL: Statement ignored
Here is the error list:
SQL> show errors
Errors for FUNCTION ISPRIME:
LINE/COL ERROR
-------- -----------------------------------------------------------------
10/1 PL/SQL: Statement ignored
10/8 PLS-00204: function or pseudo-column 'COUNT' may be used inside a
SQL statement only
13/1 PL/SQL: Statement ignored
13/8 PLS-00204: function or pseudo-column 'COUNT' may be used inside a
SQL statement only

Answer 1

COUNT is reserve sql word, have a look at this as an alternative solution for this task.
DECLARE
value_ NUMBER default :A;
i NUMBER DEFAULT 5;
is_prime VARCHAR2(5 CHAR);
BEGIN
IF value_ = 2 OR value_ = 3 THEN
is_prime := 'TRUE';
ELSIF MOD(value_,2)=0 OR MOD(value_,3)=0 OR value_ <= 1 THEN
is_prime := 'FALSE';
END IF;
WHILE POWER(i,2) <= value_ LOOP
IF MOD(value_,i)=0 OR MOD(value_,i + 2)=0 THEN
is_prime := 'FALSE';
exit;
END IF;
i := i + 6;
end loop;
is_prime := nvl(is_prime,'TRUE');
DBMS_Output.Put_Line(is_prime||' IT IS '||CASE is_prime WHEN 'FALSE' THEN 'NOT' END||'A PRIME NUMBER');
END;