Having errors in basic for loop

Question

Folks
I am tring to write SQL script that implements a block that contains a for-loop which increments a counter from 1 to 10 and inserts the counter value into the results field of the LOOPING table that i have created. i want to insert a null val in place of the counter if the counter value is equal to either 6 or 8.
Below are my work
Table creation
CREATE TABLE LOOPING (Result VARCHAR2(60));
I am expecting a output like this
Result
1
2
3
4
5
NULL
7
Null
9
10
My SCRIPT
BEGIN
FOR COUNTER IN 1..10
IF ((COUNTER = 6 ) AND (COUNTER = 8 ))
THEN
INSERT INTO MESSAGES
VALUES(NULL);
ELSE
INSERT INTO MESSAGES
VALUES(COUNTER);
END LOOP;
END;
I am getting errors. I am a beginner . Please help me out .
can you point out my errors and explain
And finaly please tell me how to correct it .
Thanks
Guna

Answer 1

1) When you get an error, it's always helpful to post the details of that error (the error number and the line number). That makes it far easier for us to help you.
2) Thank you for posting your code and table definition. That definitely helps! In the future, you'll want to use the \ tag (6 characters, all lower case) before and after any code fragments to preserve the white space & indentation.  That makes your code far easier to read.
3) Your code fails to compile because
- you are missing the LOOP keyword between lines 2 and 3
- you are missing the END IF at the end of your IF statement
- you are referring to a table named MESSAGES while your CREATE TABLE statement refers to a table named LOOPING
If you correct those three errors, your code will compile
[code]
SQL> ed
Wrote file afiedt.buf
  1  BEGIN
  2    FOR COUNTER IN 1..10
  3    LOOP -- Added
  4      IF ((COUNTER = 6 ) AND (COUNTER = 8 ))
  5      THEN
  6        INSERT INTO looping -- Changed table name
  7          VALUES(NULL);
  8      ELSE
  9        INSERT INTO looping -- Changed table name
10          VALUES(COUNTER);
11      END IF; -- Added
12    END LOOP;
13* END;
SQL> /
PL/SQL procedure successfully completed.
[/code]
4) However, now that the code compiles, you'll have a problem that it does not meet the requirements.  It will never insert a NULL value because your IF condition is incorrect.  Since this looks like a homework problem, however, I don't want to completely give it away-- I've probably done more than I should have already.
Justin