Pl/SQL problem with syntax in validation code - sql

Question

Trying to write this type of script in PL / SQL on the second line with "WHEN", I get a syntax error. Please help
The function should validate and contain the logic it is trying to write
I don't have much experience. How could I write it differently?
create or replace FUNCTION BUSINESS_PROVIDER_GET(valueGet IN VARCHAR2)
RETURN VARCHAR2
IS
v_value business_provider_configuration.billing_account_id%TYPE ;
BEGIN
DECLARE
V_BUSINESS_PROVIDER business_provider_configuration.business_provider%TYPE;
V_TRADING_NAME business_provider_configuration.trading_name%TYPE;
V_CUSTOMER_ID business_provider_configuration.customer_id%TYPE;
V_PROVIDER BUSINESS_PROVIDER_CONFIGURATION%TYPE;
BEGIN
SELECT
*
INTO V_BUSINESS_PROVIDER
FROM
BUSINESS_PROVIDER_CONFIGURATION
WHERE
V_BUSINESS_PROVIDER = valueGet
AND
Upper(V_BUSINESS_PROVIDER) = Upper (valueGet);
EXCEPTION
WHEN no_data_found THEN
SELECT
*
INTO V_TRADING_NAME
FROM
BUSINESS_PROVIDER_CONFIGURATION
WHERE
V_TRADING_NAME = valueGet
AND
Upper(V_TRADING_NAME) = Upper (valueGet);
EXCEPTION
WHEN no_data_found THEN
SELECT
*
INTO V_CUSTOMER_ID
FROM
BUSINESS_PROVIDER_CONFIGURATION
WHERE
V_CUSTOMER_ID = valueGet
AND
Upper(V_CUSTOMER_ID) = Upper (valueGet);
EXCEPTION
WHEN no_data_found
raise_application_error(-20000, 'Not found');

Answer 1

Exception is 'end-of-block' keyword - you can't just pull it out of nowhere multiple times in the same block.
In function you are allowed to have one exception statement, because function body is block on it's own.
If inside exception block you want to handle another exception, the code which may raise that exception must be inside a block.
It helps a lot to fix such issues when code is properly indented - i had to do it here:
create or replace FUNCTION BUSINESS_PROVIDER_GET(valueGet IN VARCHAR2)
RETURN VARCHAR2
IS
v_value business_provider_configuration.billing_account_id%TYPE ;
BEGIN
DECLARE
V_BUSINESS_PROVIDER business_provider_configuration.business_provider%TYPE;
V_TRADING_NAME business_provider_configuration.trading_name%TYPE;
V_CUSTOMER_ID business_provider_configuration.customer_id%TYPE;
V_PROVIDER BUSINESS_PROVIDER_CONFIGURATION%TYPE;
BEGIN
SELECT *
INTO V_BUSINESS_PROVIDER
FROM BUSINESS_PROVIDER_CONFIGURATION
WHERE V_BUSINESS_PROVIDER = valueGet
AND Upper(V_BUSINESS_PROVIDER) = Upper (valueGet);
EXCEPTION
WHEN no_data_found THEN
BEGIN -- Block that can raise second exception
SELECT *
INTO V_TRADING_NAME
FROM BUSINESS_PROVIDER_CONFIGURATION
WHERE V_TRADING_NAME = valueGet
AND Upper(V_TRADING_NAME) = Upper (valueGet);
EXCEPTION
WHEN no_data_found THEN
BEGIN -- Block that can raise third exception
SELECT *
INTO V_CUSTOMER_ID
FROM BUSINESS_PROVIDER_CONFIGURATION
WHERE V_CUSTOMER_ID = valueGet
AND Upper(V_CUSTOMER_ID) = Upper (valueGet);
EXCEPTION
WHEN no_data_found
raise_application_error(-20000, 'Not found');
END; -- End of block that can raise third exception
END; -- End of block that can raise second exception
END BUSINESS_PROVIDER_GET; -- End of function body
I do not have your tables so i was not able to test it, there might still be some issues here.
Also, the code is a little bit of mess- you should not have to look in multiple columns that have distinct business meaning for just one value.
And i have no idea, how do you want to 'select *' into single scalar variable from a table, that has multiple columns - just specify, which column you want to fetch.
I would argue that 'select *' should never be used in stored code, unless you fetch into record variable that inherits rowtype from table.

Answer 2

First of all, the conditions as you are using them will never return any values. You are defining the variable, for example V_BUSINESS_PROVIDER and right after that compare it against valueGet. Since the V_BUSINESS_PROVIDER is null the result of conditions will be always false
Second, the set of conditions
V_BUSINESS_PROVIDER = valueGet
AND Upper(V_BUSINESS_PROVIDER) = Upper(valueGet);
is reduntant. If you need values to be exactly the same case (e.g. 'Word' <> 'wORD') you have to use only lines like this
V_BUSINESS_PROVIDER = valueGet
otherwise, if you don't need to compare cases (e.g. 'Word' = 'wORD') you need to use such conditions only
AND Upper(V_BUSINESS_PROVIDER) = Upper(valueGet)
Third. As I see the aim is to get column values into variables named after them. In this case you have to specify the column names in the select statement. E.g.
select business_provider
into V_BUSINESS_PROVIDER
FROM BUSINESS_PROVIDER_CONFIGURATION
....
Fourth thing is the using exception handlers for non-handling purpose is a bad idea. I'd recomment you to rewrite this part like the following
create or replace FUNCTION BUSINESS_PROVIDER_GET(valueGet IN VARCHAR2)
RETURN VARCHAR2
IS
v_value business_provider_configuration.billing_account_id%TYPE ;
V_BUSINESS_PROVIDER business_provider_configuration.business_provider%TYPE;
V_TRADING_NAME business_provider_configuration.trading_name%TYPE;
V_CUSTOMER_ID business_provider_configuration.customer_id%TYPE;
V_PROVIDER BUSINESS_PROVIDER_CONFIGURATION%TYPE;
BEGIN
begin
select ... into V_BUSINESS_PROVIDER ...;
exception
when no_data_found then
V_BUSINESS_PROVIDER := null;
end;
if V_BUSINESS_PROVIDER is null then
begin
select ... into V_TRADING_NAME ...;
exception
when no_data_found then
V_TRADING_NAME := null;
end;
end if;
if V_TRADING_NAME is null then
begin
select ... into V_CUSTOMER_ID ...;
exception
when no_data_found then
raise(...); -- though I'm not sure if you have to raise it, the no_data_found will get raised anyway you can handle the native exception
end;
end if;
end BUSINESS_PROVIDER_GET;