OUTSIDE LOOP COUNTER SEEN 0 - sql

Question

Their TOT and CNT are getting 0 after Loop running. My input is 5 but the result always got 0 why?? I want to input multiple times by the user. Is it possible???????
DECLARE
TOT NUMBER:=0;
CNT NUMBER:=0;
AVG1 NUMBER:=0;
A NUMBER;
B NUMBER;
BEGIN
A := TO_NUMBER(&INPUT_NUMBER);
DBMS_OUTPUT.PUT_LINE('A ====='||A);
WHILE(CNT > A)
LOOP
TOT := TOT+ A;
CNT := CNT + 1;
END LOOP;
AVG1:= TOT/CNT;
DBMS_OUTPUT.PUT_LINE('AVERAGE ============'|| AVG1);
END;
/

Answer 1

cnt is 0 and a is 5 and your loop condition is WHILE(CNT > A) and since 0 > 5 is false then the loop will never run.
You probably want WHILE(CNT < A).
DECLARE
TOT NUMBER:=0;
CNT NUMBER:=0;
AVG1 NUMBER:=0;
A NUMBER:=TO_NUMBER(&INPUT_NUMBER);
BEGIN
DBMS_OUTPUT.PUT_LINE('A ====='||A);
WHILE(CNT < A)
LOOP
TOT := TOT+ A;
CNT := CNT + 1;
END LOOP;
AVG1:= TOT/CNT;
DBMS_OUTPUT.PUT_LINE('AVERAGE ============'|| AVG1);
END;
/
However, since all you are doing is adding A multiple times then you will end up with CNT := A (or 0 if A is negative) and TOTAL := CNT*A and, for positive numbers, the average will be A*CNT/CNT which is simply A so your code could be simplified to:
DECLARE
A NUMBER:=TO_NUMBER(&INPUT_NUMBER);
CNT NUMBER:=GREATEST(A,0);
TOT NUMBER:=CNT*A;
AVG1 NUMBER:=TOT/CNT;
BEGIN
DBMS_OUTPUT.PUT_LINE('A ====='||A);
DBMS_OUTPUT.PUT_LINE('AVERAGE ============'|| AVG1);
END;
/
fiddle
The input value should be inside the loop. I want input multiple times by the user.
That is impossible.
A substitution variable is processed on the SQL*Plus client and acts as if a find-replace has been performed on your code and then the updated SQL text is sent to the SQL engine on the database server without the substitution variable. The database NEVER sees the variables (and if it did it would not understand them) as they are entirely processed on the client side.
The SQL*Plus client does not run the code when it processes the substitution variables so it will not unroll the loops and request multiple inputs from the user; it will just replace the value once and send the updated text to the server to process.