[solved] Unable to use ZeosLib with multiple connections

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Sorien
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Joined: 18.04.2012, 12:29

[solved] Unable to use ZeosLib with multiple connections

Post by Sorien »

When i try to query for data changed during another connection, zeos components will not return correct data

steps to reproduce problem:

#1, 1st connection calls query like
SELECT DISTINCT(data) FROM test_table

and result is 1, 2, 3, 4, 5

Code: Select all

query:= TZReadOnlyQuery.Create(nil);
query.Connection := ZConnection1;
query.SQL.Text:= 'SELECT DISTINCT(data) FROM test_table';
query.Open;

while not query.Eof do begin
  Memo1.Lines.Add(query.Fields[0].AsString);
  query.Next;
end;

query.Close;
#2, 2nd connection/external editor updates data to 1, 9, 3, 4, 5

#3, when i execute first query(code block) again from 1st connection it will return 1, 2, 3, 4, 5 instead of 1, 9, 3, 4, 5 query will not return fresh data but cached.

tested with mysql and firebird connections using egonhugeist branch revision 1338 and 1645, old DBX components don't have this problem
Zeos 7.0 - egonhugeist branch, DB charset and collation UTF-8, Connection UTF-8, Win7 64Bit
marsupilami
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Joined: 17.01.2011, 14:17

Post by marsupilami »

Hello Sorien,

which transaction isolation level did you set in the first connection component? I tried this with Firebird 2.1 and a transaction isolation of tiReadCommitted and things worked as expected.
Best regards,

Jan
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EgonHugeist
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Posts: 1936
Joined: 31.03.2011, 22:38

Post by EgonHugeist »

Sorien,

i answered your pm. i think Jan is right here.. IF the external editor OR Zeos(no AutoCommit) using "sessions" then it is impossible to see the changes between the two apps.

Michael
Best regards, Michael

You want to help? http://zeoslib.sourceforge.net/viewtopic.php?f=4&t=3671
You found a (possible) bug? Use the new bugtracker dude! http://sourceforge.net/p/zeoslib/tickets/

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Sorien
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Posts: 13
Joined: 18.04.2012, 12:29

Post by Sorien »

its working, ty guys
Zeos 7.0 - egonhugeist branch, DB charset and collation UTF-8, Connection UTF-8, Win7 64Bit
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