SQL Procedure Errors - oracle

Question

i am learning mysql and have moved onto procedures. I have created a procedure and i am trying to run it. But when I run the procedure i am faced with lots of errors, the error point to lines that have no errors that I can see, can anyone help me out?
This is the procedure I have created
create or replace PROCEDURE AD_AGENCY_INFO(
v_ad_id IN ad_agency.AGENCY_ID%TYPE,
v_cert IN ad_agency.NO_OF_AD_RUNS%TYPE,
v_price IN ad_agency.CREDIT_WORTHY%TYPE,
v_agency_id IN ad_agency.AGENCY_ID%TYPE
) AS
BEGIN
UPDATE AD SET AD_ID = v_ad_id, CERTIFICTAION = v_cert, PRICE = v_price where agency_id = v_agency_id;
INSERT INTO AD_SLOT (AD_ID) VALUES (v_ad_id);
EXCEPTION
WHEN NO_DATA_FOUND THEN
rollback;
END AD_AGENCY_INFO;
This is how I am calling the procedure
DECLARE
V_AGENCY_ID NUMBER:=&Enter_Agency_ID;
V_NO_OF_RUNS NUMBER:=&Enter_No_of_Runs;
V_CREDIT_WORTHY CHAR(3):=&Enter_Credit_Worthy;
V_AVAILABLE_SLOTS NUMBER:=&Enter_Available_Slots;
V_STATUS CHAR(1):=&Enter_Status;
BEGIN
V_AGENCY_ID := NULL;
V_NO_OF_RUNS := NULL;
V_CREDIT_WORTHY := NULL;
V_AVAILABLE_SLOTS := NULL;
V_STATUS := NULL;
AD_AGENCY_INFO(
V_AGENCY_ID => V_AGENCY_ID,
V_NO_OF_RUNS => V_NO_OF_RUNS,
V_CREDIT_WORTHY => V_CREDIT_WORTHY,
V_AVAILABLE_SLOTS => V_AVAILABLE_SLOTS,
V_STATUS => V_STATUS
);
END;
And this is the error log I get after running the procedure
Error report -
ORA-06550: line 4, column 28:
PLS-00201: identifier 'N' must be declared
ORA-06550: line 4, column 19:
PL/SQL: Item ignored
ORA-06550: line 6, column 21:
PLS-00201: identifier 'Y' must be declared
ORA-06550: line 6, column 12:
PL/SQL: Item ignored
ORA-06550: line 10, column 3:
PLS-00320: the declaration of the type of this expression is incomplete or malformed
ORA-06550: line 10, column 3:
PL/SQL: Statement ignored
ORA-06550: line 12, column 3:
PLS-00320: the declaration of the type of this expression is incomplete or malformed
ORA-06550: line 12, column 3:
PL/SQL: Statement ignored
ORA-06550: line 17, column 24:
PLS-00320: the declaration of the type of this expression is incomplete or malformed
ORA-06550: line 14, column 3:
PL/SQL: Statement ignored
06550. 00000 - "line %s, column %s:\n%s"
*Cause: Usually a PL/SQL compilation error.
*Action:

Answer 1

In the script that you're using to call the procedure, you're using substitution variables. They are replaced by their value before the script is interpreted. This means that a line like V_CREDIT_WORTHY CHAR(3):=&Enter_Credit_Worthy; with the value "no" will be translated into V_CREDIT_WORTHY CHAR(3):=no; You'll notice that "no" is unquoted there. In order to use substitution variables to pass a string to a PL/SQL script, you need to enclose the bind variable in quotes: V_CREDIT_WORTHY CHAR(3):='&Enter_Credit_Worthy';.
An alternative would be to use bind variables. They are interpreted as a part of the script and can therefore be treated as normal variable. To do this, you would simply need to replace the ampersands with colons. The line I referenced above would become V_CREDIT_WORTHY CHAR(3):=:Enter_Credit_Worthy;.