Stored procedure on Sybase returns empty result set.

Problem

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I have a stored procedure on Sybase that returns a return value and result sets. Whenever I test the return value first, my result set is empty.

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Cause

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This has to do with the way the Sybase DBLibrary processes result sets and return values (or output parameters). Result sets and return values can only be accessed in a manner similar to that of a singly-linked list. It is not possible to access the return value without iterating through the complete result set first. This is not a DBTools.h++ bug.

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Action

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When returning a return value or output parameter and a result sets from a Sybase stored procedure, it is very important to process the result first, then get the return value or the output parameters. Result sets can be stored temporarily into a memory table first and be processed later.

Sample Code:

            RWDBDatabase database =
              RWDBManager::database("SYBASE","user","pwd","DB");
            RWDBConnection conn = database.connection();
            // test proc returns result sets and value
            RWDBStoredProc sproc=database.storedProc("testproc");
            RWDBResult res = sproc.execute(conn);
            RWDBMemTable memTab(res.table().reader(conn));
                if(sproc.returnValue().asInt()==1)
            { 
            // Process results here from the memTab
            }