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Editorial Team
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Asked: 2026-05-25T11:42:47+00:00

I’m a little new to DB2, and am having trouble developing a query. I

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I’m a little new to DB2, and am having trouble developing a query. I have created a user-defined function that returns a table of data which I want to then join and select from in larger select statement. I’m working on a sensitive db, so the query below isn’t what I’m literally running, but it’s almost exactly like it (without the other 10 joins I have to do lol).

select 
  A.customerId,
  A.firstname,
  A.lastname,
  B.orderId,
  B.orderDate,
  F.currentLocationDate,
  F.currentLocation
from 
  customer A
  INNER JOIN order B
    on A.customerId = B.customerId
  INNER JOIN table(getShippingHistory(B.customerId)) as F
    on B.orderId = F.orderId
where B.orderId = 35

This works great if I run this query without the where clause (or some other where clause that doesn’t check for an ID). When I include the where clause, I get the following error:

Error during Prepare 58004(-901)[IBM][CLI Driver][DB2/LINUXX8664]
SQL0901N The SQL statement failed because of a non-severe system
error. Subsequent SQL statements can be processed. (Reason “Bad Plan;
Unresolved QNC found”.) SQLSTATE=58004

I have tracked the issue down to fact that I’m using one of join criteria for the parameters (B.customerId). I have validated this fact by replacing B.customerId with a valid customerId, and the query works great. Problem is, I don’t know the customerId when calling this query. I know only the orderId (in this example).

Any thoughts on how to restructure this so I can make only 1 call to get all the info? I know the plan is the problem b/c the customerId isn’t getting resolved before the function is called.

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1 Answer

  1. Editorial Team

    i found the best solution (given the current query structure) is to use a LEFT join instead of an INNER join in order force the LEFT part of the join to happen which will resolve the customerId to a value by the time it gets to the function call.

    select 
  A.customerId,
  A.firstname,
  A.lastname,
  B.orderId,
  B.orderDate,
  F.currentLocationDate,
  F.currentLocation
from 
  customer A
  INNER JOIN order B
    on A.customerId = B.customerId
  LEFT JOIN table(getShippingHistory(B.customerId)) as F
    on B.orderId = F.orderId
where B.orderId = 35
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