PowerBuilder 12.5 sql cursors transaction size error - sql

Question

i have a major problem and trying to find a workaround. I have an application in PB12.5 that works on both sql and oracle dbs.. (with a lot of data)
and i m using CURSOR at a point,, but the aplications crashes only in sql. Using debuging in PB i found that the sql connection returs -1 due to huge transaction size. But i want to fetch row by row my data.. is any work around to fetch data like paging?? i mean lets fetch the first 1000 rows next the other 1000 and so on.. i hope that you understand what i want to achieve (to break the fetch process and so to reduce the transaction size if possible) , here is my code
DECLARE trans_Curs CURSOR FOR
SELECT associate_trans.trans_code
FROM associate_trans
WHERE associate_trans.usage_code = :ggs_vars.usage ORDER BY associate_trans.trans_code ;
OPEN trans_Curs;
FETCH trans_Curs INTO :ll_transId;
DO WHILE sqlca.sqlcode = 0
ll_index += 1
hpb_1.Position = ll_index
if not guo_associates.of_asstrans_updatemaster( ll_transId, ls_error) then
ROLLBACK;
CLOSE trans_Curs;
SetPointer(Arrow!)
MessageBox("Update Process", "Problem with the update process on~r~n" + sqlca.sqlerrtext)
cb_2.Enabled = TRUE
return
end if
FETCH trans_Curs INTO :ll_transId;
LOOP
CLOSE trans_Curs;

Answer 1

Since the structure of your source table s not fully presented, I'll make some assumptions here.
Let's assume that the records include a unique field that can be used as a reference (could be a counter or a timestamp). I'll assume here that the field is a timestamp.
Let's also assume that PB accepts cursors with parameters (not all solutions do; if it does not, there are simple workarounds).
You could modify your cursor to be something like:
[Note: I'm assuming also that the syntax presented here is valid for your environment; if not, adaptations are simple]
DECLARE TopTime TIMESTAMP ;
DECLARE trans_Curs CURSOR FOR
SELECT ots.associate_trans.trans_code
FROM ots.associate_trans
WHERE ots.associate_trans.usage_code = :ggs_vars.usage
AND ots.associate_trans.Timestamp < TopTime
ORDER BY ots.associate_trans.trans_code
LIMIT 1000 ;
:
:
IF (p_Start_Timestamp IS NULL) THEN
TopTime = CURRENT_TIMESTAMP() ;
ELSE
TopTime = p_Start_Timestamp ;
END IF ;
OPEN trans_Curs;
FETCH trans_Curs INTO :ll_transId;
:
:
In the above:
p_Start_Timestamp is a received timestamp parameter which would initially be empty and then will contain the OLDEST timestamp fetched in the previous invocation,
CURRENT_TIMESTAMP() is a function of your environment returning the current timestamp.
This solution will work solely when you need to progress in one direction (i.e. from present to past) and that you are accumulating all the fetched records in an internal buffer in case you need to scroll up again.
Hope this makes things clearer.

Answer 2

First of all thank you FDavidov for your effort, so i managed to do it using dynamic datastore instead of cursor,, so here is my solution in case someone else need this.
String ls_sql, ls_syntax, ls_err
Long ll_row
DataStore lds_info
ls_sql = "SELECT associate_trans.trans_code " &
+ " FROM associate_trans " &
+ " WHERE associate_trans.usage_code = '" + ggs_vars.usage +"' "&
+ " ORDER BY associate_trans.trans_code"
ls_syntax = SQLCA.SyntaxFromSQL( ls_sql, "", ls_err )
IF ls_err <> '' THEN
MessageBox( 'Error...', ls_err )
RETURN
END IF
lds_info = CREATE DataStore
lds_info.Create( ls_syntax, ls_err )
lds_info.SetTransObject( SQLCA )
lds_info.Retrieve( )
DO WHILE sqlca.sqlcode = 0 and ll_row <= ll_count
FOR ll_row = 1 TO ll_count
ll_transId = lds_info.GetItemNumber( ll_row, 'trans_code' )
ll_index += 1
hpb_1.Position = ll_index
do while yield(); loop
if not guo_associates.of_asstrans_updatemaster( ll_transId, ls_error) then
ROLLBACK;
DESTROY lds_info
SetPointer(Arrow!)
MessageBox("Update Process", "Problem with the update process on~r~n" + sqlca.sqlerrtext)
cb_2.Enabled = TRUE
return
end if
NEXT
DESTROY lds_info
LOOP