This function is used to return the total number of orders for a shopper using their ID. Every time I try to throw an exception, nothing happens. It will return a null value. For example, IDSHOPPER = 19 does not exist within BB_BASKET, so I was thinking that I could throw an exception if lv_total_orders = 0, but it was still returning a null value and DBMS_OUTPUT.PUT_LINE would not show anything in the output. Could anyone suggest how to throw an exception for this function if I were to use a IDSHOPPER that does not exist in BB_BASAKET? This is for homework for my class, but I have done most of the work except for the exception which is required. I cannot find anything that suggests how to execute an exception.
CREATE OR REPLACE FUNCTION NUM_PURCH_SF
(p_shopper IN NUMBER)
RETURN NUMBER
AS
lv_total_orders NUMBER(3);
BEGIN
SELECT SUM(ORDERPLACED)
INTO lv_total_orders
FROM BB_BASKET
WHERE IDSHOPPER = p_shopper
AND ORDERPLACED = 1;
RETURN lv_total_orders;
END;
SELECT NUM_PURCH_SF(IDSHOPPER)
FROM BB_SHOPPER
WHERE IDSHOPPER = 23;
Aggregation functions always returns single row, even if no rows match the condition. You can look at this article
So, if you want to throw exception, you can use raising exceptions explicitly.
In your code, before return statement:
if lv_total_orders is null then
raise_application_error(-20200, 'No data found for given ShopperID, ShopperID: ' || p_shopper);
end if;
Related
So I have a procedure below that accept a date as an IN parameter. If a wrong type of parameter is passed in, the exception area will not be able to catch it because the parameter is used in the CURSOR declaration section.
PROCEDURE ABC(p_date IN DATE)
IS
CURSTOR cur
IS
SELECT *
FROM table
WHERE table.date = TRUNC(p_date);
BEGIN
do something;
EXCEPTION
WHEN OTHERS THEN
do something;
END;
If the user passes a wrong parameter type:
BEGIN
ABC(123);
END;
I'll get the "wrong number or types of arguments in call to 'ABC'" error.
Is there a way to handle this error under this scenario?
Micklesh is correct. An error in calling the procedure isn't handled by the called procedure, it needs to be handled in the calling procedure.
I have a pl sql code that execute three queries sequentially to determine a match level and do some logic
The issue is - when first query has no results (completely valid scenario) I get ORA-01403 No data found.
I understand that I need to incorporate [ Exception clause when NO_DATA_FOUND ]- but how to add it and continue to the next query?
PL/SQL Code
SELECT A into PARAM A FROM SAMPLE WHERE SOME CONDITION;
-- GOT ORA-01403 No data found HERE
MATCH_LEVEL =1;
if A is null then
do some logic;
end if
SELECT A INTO PARAM_B FROM SAMPLE WHERE SOME OTHER CONDITION
MATCH_LEVEL =2
if A is null then
do some logic 2;
end if
SELECT A INTO PARAM_B FROM SAMPLE WHERE SOME OTHER CONDITION
MATCH_LEVEL =3
if A is null then
do some logic 3;
end if
END PL/SQL Code
Declare
--your declarations
begin
SELECT A into PARAM A FROM SAMPLE WHERE SOME CONDITION;
-- GOT ORA-01403 No data found HERE
Begin
MATCH_LEVEL =1;
if A is null then
do some logic;
end if;
EXCEPTION
WHEN NO_DATA_FOUND THEN
dbms_output.put_line ('Error...');
END;
--- and son on for other blocks
end;
Just surround your SELECT INTO with begin-end;
begin
-- your faulty statement here
Exception
When NO_DATA_FOUND Then
-- Do what you want or nothing
WHEN TOO_MANY_ROWS THEN
-- what if you get more then one row? and need specific handler for this
When OTHERS Then
-- do something here or nothing (optional - may happen if you have more than your SELECT INTO between 'begin' and 'Exception')
end;
This is like try block of PL/Sql
With this technique you can log the reason your statement failed.
For a SELECT ... INTO ... statement, the PL/SQL engine assume there will be one, and only one row returned by your query. If there is no row, or more than one, an exception is raised.
FWIW, you can handle such cases without resorting on exception handling by using aggregate functions. That way, there will always be only one row in the result set.
Assuming A can't be NULL in your rows:
SELECT MAX(A) into PARAM A FROM SAMPLE WHERE SOME CONDITION;
-- A would be NULL if there was *no* row. Otherwise, it is *the* value for *the* row
MATCH_LEVEL =1;
if A is null then
do some logic;
end if
If the NULL value is a possible case, just add an extra COUNT(*) column:
SELECT MAX(A), COUNT(*) into A, HAS_FOUND_ROW FROM SAMPLE WHERE SOME CONDITION;
if HAS_FOUND_ROW > 0 then
...
end if;
Oracle will not allow you to open an implicit cursor (i.e. a select statement in the body of a code block) that returns no rows. You have two options here (3 really, counting #Sylvain's answer, but that is an unusual approach): use an explicit cursor or handle the error.
Explicit Cursor
An explicit cursor is one found in the DECLARE section it must be opened and fetched manually (or in a FOR loop). This has the added advantage that, if you parameterize the query properly, you can write it once and use it multiple times.
DECLARE
a sample.a%type;
MATCH_LEVEL number;
cursor cur_params (some_column_value number) is
SELECT A FROM SAMPLE WHERE some_column = some_column_value;
BEGIN
MATCH_LEVEL := 1;
open cur_params (match_level);
fetch cur_params into a;
close cur_params;
if A is null then
null; --some logic goes here
end if;
MATCH_LEVEL := 2;
open cur_params (match_level);
fetch cur_params into a;
close cur_params;
if A is null then
null; --some logic goes here
end if;
end;
Handle the error
If you choose to handle the error, you'll need to create a BEGIN...END block around the code that is going to throw the error. When disregarding an error, it's crucial that you ensure that you are only disregarding the specific error you want avoid, when generated from the specific statement you expect it from. If you simply add the EXCEPTION section to your existing BEGIN...END block, for instance, you couldn't know which statement generated it, or even if it was really the error you expected.
DECLARE
a sample.a%type;
MATCH_LEVEL number;
BEGIN
MATCH_LEVEL := 1;
BEGIN
SELECT A into A FROM SAMPLE WHERE some_column = MATCH_LEVEL;
EXCEPTION
WHEN NO_DATA_FOUND THEN
null; --Do nothing
END;
if A is null then
null; --some logic goes here
end if;
MATCH_LEVEL := 2;
BEGIN
SELECT A into A FROM SAMPLE WHERE some_column = MATCH_LEVEL;
EXCEPTION
WHEN NO_DATA_FOUND THEN
null; --Do nothing
END;
if A is null then
null; --some logic goes here
end if;
end;
While I'd discourage it, you can catch any other errors in the same exception blocks. However, by definition, those errors would be unexpected, so it would be a poor practice to discard them (you'll never know they even happened!). Generally speaking, if you use a WHEN OTHERS clause in your exception handling, that clause should always conclude with RAISE;, so that the error gets passed up to the next level and is not lost.
I'm designing a function that is part of a larger package. The function is intended to take a District Code and return a collection of unique IDs for 10-15 stores that are assigned to that district. The function is intended to return a collection that can be queried like a table, i.e., using the TABLE function in a SQL statement.
I've created the following Types:
Schema Level type:
create or replace TYPE HDT_CORE_ORGIDS AS TABLE OF CHAR(20);
and a Type inside the Package
TYPE CORE_ORGIDS IS TABLE OF CHAR(20) INDEX BY BINARY_INTEGER;
Here's the function code:
FUNCTION FindDistrictOrgs(
ParamOrgCode VARCHAR2
)
RETURN HDT_CORE_ORGIDS
AS
ReturnOrgs HDT_CORE_ORGIDS := HDT_CORE_ORGIDS();
FDOTemp HDT_CORE_MAIN.CORE_ORGIDS;
i BINARY_INTEGER := 0;
CURSOR FDOCurr IS
SELECT org.id AS OrgID
FROM tp2.tpt_company org
WHERE LEVEL = 2
START WITH org.name = ParamOrgCode
CONNECT BY PRIOR org.id = org.parent_id;
BEGIN
OPEN FDOCurr;
LOOP
i := i +1;
FETCH FDOCurr INTO FDOTemp(i);
EXIT WHEN FDOCurr%NOTFOUND;
END LOOP;
IF FDOTemp.EXISTS(FDOTemp.FIRST) THEN
ReturnOrgs.EXTEND(FDOTemp.LAST);
FOR x IN FDOTemp.FIRST .. FDOTemp.LAST LOOP
ReturnOrgs(x) := FDOTemp(x).OrgID;
END LOOP;
END IF;
CLOSE FDOCurr;
RETURN ReturnOrgs;
END FindDistrictOrgs ;
I'm getting the PLS-00487:Invalid Reference to variable 'CHAR' at the line:
ReturnOrgs(x) := FDOTemp(x).OrgID;
I've double-checked at the value returned by the SQL (the org.id AS OrgID) is of the CHAR(20 BYTE) datatype.
So...what's causing the error?
Any help is appreciated! :)
OrgID is the alias you gave the column in your cursor, it has no meaning to the collection. Since both collections are of simple types you should just be doing:
ReturnOrgs(x) := FDOTemp(x);
The syntax you're using is implying FDOTemp is a collection of objects and you're trying to reference the OrgID attribute of an object; but since CHAR isn't an object type, this errors. The error message even makes some sense when viewed like that, though it's not terribly helpful if you don't already know what's wrong... and not entirely helpful when you do.
Incidentally, you could use a bulk collect to populate the collection without the cursor or loops, or the extra collection:
SELECT org.id
BULK COLLECT INTO ReturnOrgs
FROM tp2.tpt_company org
WHERE LEVEL = 2
START WITH org.name = ParamOrgCode
CONNECT BY PRIOR org.id = org.parent_id;
RETURN ReturnOrgs;
I am trying to write a following PL/SQL function body for a dynamic action
The purpose of dynamic action is to set value for text area based on input parameters. Way I am trying to do it, is that setting the value into variable for different options
declare
P_NOTE varchar(100); -- derive value
P_WEBSERVER varchar(100); -- derive name
begin
-- for getting the P_NOTE value
select distinct note into P_NOTE from port_mapping where PLATFORM = :P3_PLATFORM and VERSION = :P3_VERSION;
-- for getting web server value
select CONCAT(P_NOTE,CONCAT('https-',:P3_CLIENT)) into P_WEBSERVER from dual order by 1;
if (:P3_PLATFORM = 'Apache') then
return P_WEBSERVER;
end if;
end;
However I am getting error
ORA-06550: line 15, column 5:
PLS-00372: In a procedure, RETURN statement cannot contain an expression
ORA-06550: line 15, column 5:
PL/SQL: Statement ignored
declare
P_NOTE varchar(100);
P_WEBSERVER varchar(100);
I am not sure what I am missing.
(Since you did not post any apex version this explanation deals with version 4.2)
If this -is- a dynamic action and the code you posted is in a true action of type 'Execute PL/SQL Code' then you can not use RETURN. The plsql block is not a function body (close, Mr Kemp!).
If you want to return values from the session state to page items then you need to use the "Page Items to Return" item of the true action.
This will put the session state of the defined page items into the value of the item on the page. This means that you can not use any variable to just put stuff in to be able to return it to the page, but you need to use an actual page item (after all, these are bind variables).
To clarify further, you would not write :
return P_WEBSERVER;
But you'd have to use a page item, say P3_WEBSERVER, and you'll need to create one if it doesn't exist of course:
:P3_WEBSERVER := p_webserver;
Of course you'd need to make sure that the correct value will be in there as you can not shortcircuit as you did in your code sample (p_webserver will usually hold a value even if the platform is not 'Apache') eg:
if (:P3_PLATFORM = 'Apache') then
:P3_WEBSERVER := P_WEBSERVER;
else
:P3_WEBSERVER := NULL;
end if;
Just read error message:
line 15, column 5
So, trouble caused by this line:
return P_WEBSERVER;
return not allowed in PL/SQL blocks, use output parameter to return a value.
Read Tom's answer to find out how to do that.
I have a function which would return a record with type my_table%ROWTYPE, and in the caller, I could check if the returned record is null, but PL/SQL complains the if-statement that
PLS-00306: wrong number or types of arguments in call to 'IS NOT NULL'
Here is my code:
v_record my_table%ROWTYPE;
v_row_id my_table.row_id%TYPE := 123456;
begin
v_record := myfunction(v_row_id)
if (v_record is not null) then
-- do something
end if;
end;
function myfunction(p_row_id in my_table.row_id%TYPE) return my_table%ROWTYPE is
v_record_out my_table%ROWTYPE := null;
begin
select * into v_record_out from my_table
where row_id = p_row_id;
return v_record_out;
end myfunction;
Thanks.
As far as I know, it's not possible. Checking the PRIMARY KEY or a NOT NULL column should be sufficient though.
You can check for v_record.row_id IS NULL.
Your function would throw a NO_DATA_FOUND exception though, when no record is found.
You can't test for the non-existence of this variable so there are two ways to go about it. Check for the existence of a single element. I don't like this as it means if anything changes your code no longer works. Instead why not just raise an exception when there's no data there:
I realise that the others in the exception is highly naughty but it'll only really catch my table disappearing when it shouldn't and nothing else.
v_record my_table%ROWTYPE;
v_row_id my_table.row_id%TYPE := 123456;
begin
v_record := myfunction(v_row_id)
exception when others then
-- do something
end;
function myfunction(p_row_id in my_table.row_id%TYPE) return my_table%ROWTYPE is
v_record_out my_table%ROWTYPE := null;
cursor c_record_out(c_row_id char) is
select *
from my_table
where row_id = p_row_id;
begin
open c_record_out(p_row_id);
fetch c_record_out into v_record_out;
if c_record_out%NOTFOUND then
raise_application_error(-20001,'no data);
end if;
close c_record_out;
return v_record_out;
end myfunction;