Date and conditions using PL/SQL - stored-procedures

Question

I am having a problem with the procedure below as whenever I pass a date of month and year, the IF condition loops on the number of records that exists in my table- only two rows existed- and also it shows the two possibilities. I also included the result to show what I mean!
PRODUCT_NUM ORDER_NUM QUANTITY PRICE MONTHLY_DATE
-------------- ----------- ------------- ------------ -------------
12345 106 3 19.99 21-DEC-15
67894 107 1 19.99 21-DEC-15
CREATE OR REPLACE PROCEDURE Proce_Name (Pram_Date DATE )
AS
BGIN
FOR Y IN
(SELECT SUM(PRICE) AS TOTAL_AMOUNT, SUM(NVL(QUANTITY,0) * NVL (
(PRICE,0)) AS TOTAL, MONTHLY_DATE
FROM PRODUCTS
GROUP BY MONTHLY_DATE
ORDER BY MONTHLY_DATE DESC) LOOP
IF TO_CHAR( Y.MONTHLY_DATE, 'mm-yyyy')= TO_CHAR(Pram_Date,'mm-yyyy') THEN
DBMS_OUTPUT.PUT_LINE('TOTAL AMOUNT: '|| ' '|| Y.TOTAL_AMOUNT);
DBMS_OUTPUT.PUT_LINE('');
DBMS_OUTPUT.PUT_LINE('TOTAL: '|| ' '|| Y.TOTAL);
ELSE
DBMS_OUTPUT.PUT_LINE('No Data for this month');
END IF;
END LOOP;
END Proce_name;
calling block:
DECLARE
MONTHLY_D DATE := TO_DATE('01-2012','mm-yyyy');
BEGIN
Proce_Name(MONTHLY_D);
END;
/
This is when the date I pass matches the records in the table:
No Data for this month
TOTAL AMOUNT: 4
TOTAL: 99.96
The result here when I pass a date that is not existed in the table:
No Data for this month
No Data for this month
How can I alter my procedure to examine the above date format accurately ?

Answer 1

Here is the code, you can consider exception handling as well:
Few observations, you an consider prem_date as char it self instead of passing date. Also if data set is huge and monthly_date is indexed, you should avoid applying to_char condition on monthly_date.
CREATE OR REPLACE PROCEDURE Proce_Name (Pram_Date DATE )
AS
l_total_amount float;
l_total float;
BEGIN
SELECT SUM(PRICE) AS TOTAL_AMOUNT,
SUM(NVL(QUANTITY,0) * NVL(PRICE,0)) AS TOTAL
INTO l_total_amount, l_total
FROM PRODUCTS
WHERE to_char(monthly_date, 'mm-yyyy') = to_char(pram_date, 'mm-yyyy');
if(l_total_amount is not null) then
DBMS_OUTPUT.PUT_LINE('TOTAL AMOUNT: '|| ' '|| L_TOTAL_AMOUNT);
DBMS_OUTPUT.PUT_LINE('');
DBMS_OUTPUT.PUT_LINE('TOTAL: '|| ' '|| L_TOTAL);
else
DBMS_OUTPUT.PUT_LINE('No Data for this month');
end if;
END Proce_name;
/

Answer 2

I have update procedure as following
CREATE OR REPLACE PROCEDURE get_sales_report(c_date date) AS
l_amount number(18, 2);
l_total number(18, 2);
BEGIN
begin
SELECT SUM(PRICE), SUM(NVL(QUANTITY, 0) * NVL(PRICE, 0))
into l_amount, l_total
FROM product
where TO_CHAR(MONTHLY_DATE, 'mm-yyyy') = to_char(c_date, 'mm-yyyy')
GROUP BY TO_CHAR(MONTHLY_DATE, 'mm-yyyy')
ORDER BY TO_CHAR(MONTHLY_DATE, 'mm-yyyy') DESC;
DBMS_OUTPUT.PUT_LINE('TOTAL AMOUNT: ' || ' ' || l_amount);
DBMS_OUTPUT.PUT_LINE('');
DBMS_OUTPUT.PUT_LINE('TOTAL: ' || ' ' || l_total);
exception
when no_data_found then
DBMS_OUTPUT.PUT_LINE('No Data for this month');
END; -- end of exception
-- add your code here
-- add your code here
-- add your code here
end;
Also call following command for dbms_output echoing text.
set serveroutput on size 30000;
Call your procedure as
declare
c_date2 DATE := TO_DATE('12-2015','mm-yyyy');
begin
get_sales_report(c_date2);
end;

Answer 3

Dates are fixed sized types. So, if you want to group by a whole month, you must query your date column as char. Meaning, you should use TO_CHAR instead of TO_DATE.
Here's (the simpler) way to do it (My changes are lowercase) -
CREATE OR REPLACE PROCEDURE Proce_Name (Pram_Date date) AS
l_month char(7);
l_total_amount number;
l_total number;
BEGIN
SELECT to_char(monthly_date,'mm-yyyy') as month,
SUM(PRICE) AS TOTAL_AMOUNT,
SUM(NVL(QUANTITY,0)*NVL(PRICE,0)) AS TOTAL
INTO l_month, l_total_amount, l_total
FROM PRODUCTS
where to_char(monthly_date,'mm-yyyy')=to_char(Pram_Date, 'mm-yyyy')
GROUP BY to_char(monthly_date,'mm-yyyy');
if l_month is not null then
DBMS_OUTPUT.PUT_LINE('TOTAL AMOUNT: '|| ' '|| Y.TOTAL_AMOUNT);
DBMS_OUTPUT.PUT_LINE('');
DBMS_OUTPUT.PUT_LINE('TOTAL: '|| ' '|| Y.TOTAL);
else
DBMS_OUTPUT.PUT_LINE('No Data for this month');
end if;
END Proce_name;
/
Here's some testing code - http://sqlfiddle.com/#!4/b1068/2