PL/SQL: statement ignored when inserting - oracle

Question

I'm trying to create a stored procedure that can only be executed in the month of march based on system date. Here is a snippot of such code:
CREATE PROCEDURE sp_time_window (
p_sales_ID in sales.sales_ID%TYPE,
p_product in sales.product%TYPE,
p_unitCost in sales.unitcost%TYPE,
p_quantity in sales.quantity%TYPE)
IS BEGIN
DECLAR v_date varchar(3)
BEGIN
SELECT TO_CHAR(sysdate,'MM') into v_date from duaL
IF (v_date in ('MAR')) THEN
INSERT INTO sales (sales_ID, product, unitcost, quantity) values
(p_sales_ID, p_ product, p_unitCost, p_quantity);
ENDIF;
END;
END;
/
ORACLE gives me this error:
LINE/COL ERROR
-------- ---------------------------------------------------
14/2 PL/SQL: SQL Statement ignored
16/5 PL/SQL: ORA-00933: SQL command not properly ended
please help

Answer 1

You have a redundant layer of BEGIN/END, and various typos, some of which I think you've just introduced creating the question, like DECLAR instead of DECLARE. But the first thing that might get that error is the missing semicolon after dual.
SELECT TO_CHAR(sysdate,'MM') into v_date from duaL;
You can assign the month value directly to the variable without the select from dual anyway:
v_date := TO_CHAR(sysdate,'MM');
... but as you have that defined as varchar2(3) and later look for MAR, that format mask should be MON not MM. However, using numbers is safer anyway, otherwise you need to be sure your session is in English. Your variable should be the appropriate type.
You also have a spaces in p_ product, and ENDIF instead of END IF, but again those might not be in your real code.
You can reduce what you have to:
CREATE OR REPLACE PROCEDURE sp_time_window (
p_sales_ID in sales.sales_ID%TYPE,
p_product in sales.product%TYPE,
p_unitCost in sales.unitcost%TYPE,
p_quantity in sales.quantity%TYPE)
AS
BEGIN
IF extract(month from sysdate) = 3 THEN
INSERT INTO sales (sales_ID, product, unitcost, quantity)
VALUES (p_sales_ID, p_product, p_unitCost, p_quantity);
END IF;
END;
/
The extract(month from sysdate) gets the month number from the date, so you can check if that is 3, as a number not a string. You also don't need the local v_date variable if you do that extraction in the IF clause.
Silently ignoring the insert seems odd, as the caller will no have no idea if that happens. And this won't stop inserts outside the procedure. In this case it might be appropriate to use a trigger that raises an exception if the month number is not 3.