John, I am not sure the GET DESCRIPTOR statement will achieve what you want.

From the manual, 'Database: Embedded SQL Programming',

"A SELECT statement with a variable SELECT list (that is, a list of columns to be returned as part of the query) that runs dynamically requires an SQL descriptor area (SQLDA). This is because you cannot know in advance how many or what type of variables to allocate in order to receive the results of the SELECT."

The SQLDA will give you the flexibility you need. However, not for the faint-hearted as you'll need to incorporate the use of based-variables, basing pointers and runtime (temporary) storage allocation. If there are only a limited number of columns and combinations that the User can select, you may wish to consider conditioning multiple Static SELECT statements, rather than building a Dynamic SELECT statement.

Just a thought.

Brian.

PS. I've found that the SQLDA structures generated by the INCLUDE SQLDA statement to be a little less refined than coding the Descriptor Area from first principles.

On 03/09/2017 21:49, John R. Smith, Jr. wrote:
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?



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