Data conversion or data mapping error HY000 in multi row concatenation in sub select in view - sql

Question

I have a sub-select as part of a view that generates a concatenated list of attributes from sub table. When doing a select from the view the data displays fine, but if it do a select in the concatenated list field I sometimes get the error Select or omit error on field.
AS400: V7R1M0
Main enitity:
MSGOCCID : CHAR 20
other fields.....
The detail entity fields (MSDPF):
MSGOCCID : CHAR 20
OCC : Integer 4
FIELDVAL : VARCHAR 128
I got the code for the sub select from StackOverflow and modified it for my situation. (I have also tried the recursive select but it very slow. The XMLSERIALIZE route is executable.)
To try and solve the problem it have added and removed REPLACE,COALESCE and TRIM of the value. I have added CCSID 1208 to the cast, changed the CHAR cast to VARCHAR... not change. (I have change CCSID 1208 to CCSID 37 at one stage to see if that will not solve it.)
If I run the select:
select MSGOCCID, COALESCE(DETLIST,' ')
from WBVIEW MSGP
where 1=1
If returns all the rows with not errors.
Sample output:
MSGOCCID: 2019020443165590
MSGDLIST: 14620, 1, C20180914023575582, 4179792C, C20180914023575582, 4179792C, WIPSTOCK, REMOVE, ROU07561
But if I use:
select MSGOCCID, COALESCE(DETLIST,' ')
from WBVIEW MSGP where 1=1 and DETLIST like '%4179792C%'
It fails with on the IBM backend:
Data conversion or data mapping error.
Select or omit error on field MapXmlData(Cast(Concat(',
',Strip(Replace(Cast(P6MSDPF_4.FIELDVAL AS VarChar(128) CCSID
1208),'-'), Both,' ')) AS VarChar(260) CCSID 1208)) member
COMMSWKBL1. Select/omit error on member COMMSWKBL1.
Short version of the view:
CREATE VIEW WBVIEW (
MSGOCCID ,
DETLIST )
AS
(SELECT MSG.MSGOCCID,
FROM P6DEVCDB00.P6MSGPF MSG
LEFT OUTER JOIN LATERAL
(SELECT XMLSERIALIZE(XMLAGG(XMLTEXT(CONCAT(', ',TRIM(REPLACE(REPLACE(REPLACE(FIELDVAL,',','-'),'>','-'),'<','-'))))) AS VARCHAR(4096) CCSID 1208) AS DETLIST
FROM MSDPF MSGDET
WHERE COALESCE(MSGDET.MSGOCCID,' ') != ' ' and
MSG.MSGOCCID = MSGDET.MSGOCCID AND
MSGDET.FIELDVAL != ''
GROUP BY MSGDET.MSGOCCID)MSGDLIST ON 1=1);
Character concatenation should not be a problem (except if it gets confused somewhere with the CCSIDs). I replace the <>, form the detail for in case that may interfere with xml functions... I have catered for Null and '' values ....
I have search lots of threads on lots of different sites and have run out of ideas.
Any suggestions will be appreciated.

Answer 1

I'm just guessing a quick comment answer here. Those left outer joins can introduce nulls into the mix you can simply coalesce them in the where clause ...
select MSGOCCID, COALESCE(DETLIST,' ')
from WBVIEW MSGP where
coalesce(DETLIST,' ') like '%4179792C%'
IRL I would use locate because it just feels faster when it runs.
select MSGOCCID, COALESCE(DETLIST,' ')
from WBVIEW MSGP where
locate('4179792C' ,coalesce(DETLIST,' ')) <> 0

Answer 2

HY000 is a CLI (ODBC) General error, the explaination in the IBM documentation is:
An error occurred for which there is no specific SQLSTATE and for which no implementation defined SQLSTATE is defined. The error message returned by SQLError in the argument szErrorMsg describes the error and its cause.
Since this is probably not something you are coding by hand, you probably do not have the opportunity to issue SQLError, but I suspect that the message you quoted in your question is the result of some internal process retrieving that error. so the problem should be:
Data conversion or data mapping error.
Select or omit error on field MapXmlData(Cast(Concat(',
',Strip(Replace(Cast(P6MSDPF_4.FIELDVAL AS VarChar(128) CCSID 1208),'-'), Both,' ')) AS VarChar(260) CCSID 1208)) member COMMSWKBL1. Select/omit error on member COMMSWKBL1.
I don't know your files, but I am guessing that there is bad data in the file and that COMMSWKBL1 is a select logical that is accessed to process the selection when you add the DETLIST like '%4179792C%' to your query. Your task is to find out which file is associated with member COMMSWKBL1, and see if you can determine why a Select or omit error would be occurring on that file.

Answer 3

It is fine. I have modified the view to select both the header and detail, and search on both entity entries (linked on the key MSGOCCID) and do a DISTINCT on the key MSGOCCID. It seems a little bit slower than the view the question is about but is working fine. Thank you for you time.