Building dynamic SQL with descriptors

I am trying to write an SQLRPGLE program that can take a dynamic SQL string
(user selected fields) and extract the data from a file. I am using
descriptors because the fields selected will be variable. For example, they
may do "select firstname, lastname, age from people" or they may do "select
lastname, firstname, gender from people. I have a lot of this working but I
have found that the field I am loading in my program has to be the exact
size of the field in the database.



In the case of firstname (20 chars) and lastname (30 chars) I am using the
below logic.



exec sql

get descriptor :descName VALUE :i

:type = TYPE,

:length = LENGTH,

:result_ind = INDICATOR;

if result_ind >= 0;

select;

when type = '1'; // character

exec sql

get descriptor :descName value:i

:charResult = DATA;

.more data types.

endsl;

endif;



What I am finding is charResult has to be 20A to extract the firstname field
but has to be 30A to extract the lastname field. If either field does not
match, I receive an SQL0076 error.



I am having the same problem with my numeric fields. Since age is a 3,0
field, my numericResult has to be a 3,0. If numericResult is anything other
then 3,0, I get the SQL0076 which means it won't work for another field that
is 5,0.



Can someone tell me what I am missing?