Refresh Dataset with SQLDB and Firebird
lazarus / 16-Databases

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jwest · 2016-03-19 03:11

Does someone can post a sample about How to do a Refresh with
TSQLQuery and SQLDB with Firebird?

Here is my pseudo code:

var
DB:TIBConnection;
Tn:TSQLTransacttion;
Qry:TSqlQuery;

DB:=TIBConnection.Create;
//set params of DB
Tn:=TSQLTransacttion.Create;
Tn.Database:=DB;

Qry:=TSqlQuery.Create;
Qry.Database:=DB;
Qry.Transactio:=Tn;
Qry.Sql.Text:='Select * from tableX';

Qry.Open;

//Insert or update TabelX in another station, and Commit;

Qry.Refresh; //No refresh is done here

But, if commit the transaction and I close and reopen the Qry, I have
the dataset refreshed.

How I do a Refresh without Commit TN, Close e Reopen Qry??

How  Refresh method works?

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mangakissa · 2016-03-19 08:16

try this with the params of your transaction:
read_committed
rec_version
nowait

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jwest · 2016-03-19 14:35

Sorry , but it doesn't work. No refresh is done with this settings.

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balazsszekely · 2016-03-19 15:24

Quote@jwest
//Insert or update TabelX in another station, and Commit;What do you
mean by "another station"? The table is updated with a different
connection? If you update the table with the same connection, after a
post, which is a logical transaction, you should see the changes
without refresh. To permanently save the data to the database use the
commit/commitretaining methods. If the changes was done in the context
of separate connection, then you need a refresh. You will be able to
see the changes only after the other connection commited the data.

Ps: Of course, all this depends on the isolation level(usually "Read
committed").

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jwest · 2016-03-19 15:28

Yes, It was updated with a different app and connection.

I just solved when I added
"isc_tpb_read_commited" in transaction params instead of 
"read_commited".

Thank you.

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rvk · 2016-03-19 18:51

Quote from: jwest on March 19, 2016, 04:28:43 pmI just solved when I
added
"isc_tpb_read_commited" in transaction params instead of 
"read_commited".
I think you mean "isc_tpb_read_committed". Notice the double T.
"isc_tpb_read_commited" shouldn't do anything. Yeah, typos like that
really make finding these problems difficult. In Delphi IBX you can
just add "read_committed" because that component puts the prefix
"isc_tpb_" in front of it. So it depends on each component what
exactly you need to provide to set the TPB parameter. But normally
nowadays the components need the complete name (with isc_tpd_ prefix).

For instance...
http://www.devrace.com/en/fibplus/articles/479.php
http://www.devrace.com/en/fibplus/articles/3292.php