Question

I have the following query:

SELECT wm_concat(DISTINCT NAME) as Methods FROM TPM_TRAININGPLAN
JOIN TPM_DELIVERYMETHODS USING (METHODID)
WHERE PROJECTID=735 AND VERSIONID=1
ORDER BY NAME

On our production database (some uber expensive Oracle SKU that costs more than my house *), it returns:

I/OLT,ILT-WEB,OLT,QRG

However, on my local Oracle Express instance (11g) which I use for development, I get the error:

>[Error] Script lines: 13-16 ------------------------
 ORA-00904: "WM_CONCAT": invalid identifier
 Script line 13, statement line 1, column 7

Does Oracle Express not support this, or is there a work-around (such as can I copy the function from our production server, or run some script to “mimic” it?) Thanks!

* No seriously it actually costs more than my house.

UPDATE:

As suggested, I tried the LISTAGG function (which is indeed included in both Express 11g and the “Shall we buy an Oracle license or a second yacht” SKU. This seems to almost work, but has a few drawbacks which I can’t find a good workaround for. First, the query:

SELECT LISTAGG(NAME, ',') WITHIN GROUP (ORDER BY NAME) Methods FROM
TPM_TRAININGPLAN
JOIN TPM_DELIVERYMETHODS USING (METHODID) WHERE PROJECTID=240 AND VERSIONID=1

Will return:

COMM,COMM,ILT-F2F,ILT-F2F,ILT-F2F,ILT-F2F,ILT-F2F

However, I want to remove the dupes. Changing NAME to DISTINCT NAME will throw the error DISTINCT option not allowed for this function

Well great, we’ll just toss a CTE in there:

WITH Methods AS
   (SELECT DISTINCT NAME
    FROM TPM_TRAININGPLAN
    JOIN TPM_DELIVERYMETHODS USING (METHODID) WHERE PROJECTID=240 AND VERSIONID=1)
SELECT LISTAGG(NAME, ',') WITHIN GROUP (ORDER BY NAME) Methods FROM Methods

This works, however I forgot to mention that I’m running this entire thing as a nested select in a larger query. It seems you can have nested selects that include a CTE, however within the query you can no longer refer to the root query, only the CTE. So now I can’t replace 240 and 1 with the appropriate values from the row I’m on.

Answer 1

if you are in 11GR2, you ought to be able to do listagg

with fake_data as(

select 'I/OLT' NAME , 1 aa from dual
union all
select 'ILT-WEB' NAME,2 from dual
union all
select 'OLT' NAME,3 from dual
union all
select 'QRG' NAME,4 from dual
)
SELECT 
       LISTAGG(NAME, ', ') WITHIN GROUP (ORDER BY name)  name_list
FROM fake_data
;

NAME_LIST                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
--------------------------
I/OLT, ILT-WEB, OLT, QRG  

I don’t have Oracle Express 11Gr2 to test this (just enterprise).
But Oracle Express does not have Java support, but you can try to implement it via custom types (once again I don’t have Express to test with!)
http://asktom.oracle.com/pls/asktom/f?p=100:11:0::NO::P11_QUESTION_ID:2196162600402