error connecting Lazarus to Oracle XE
lazarus / 16-Databases

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lawlerp · 2013-11-09 21:54

Hi I was wondering if somebody could help me with a problem I am
having connecting Lazarus 1.0.12 to an Oracle 11g XE database.

I am using
Lazarus 1.0.12
Oracle XE Version 11.2.0
Windows XP (32 Bit)

I have created a form on which I have dropped the following controls
an OracleConnection a SQLTransaction a SQLQuery a datasource and  a DB
Grid control
OracleConnection properties set as follows
DatabaseName = XE
Hostname=localhost
Username =  ituser
Password = XXXXXX
Once these properties were set I set the Connected property to True

Next I set the SQLTransaction properties as follows
Database=OracleConnection1
Active = True
I noticed afterwards that the OracleConnection.Transaction property
was set to SQLTransaction1

Next I set the SQLQuery1.Transaction property to SQLTransaction1. This
had the effect of setting the SQLQuery1.database property to
OracleConnection1.  When I tried to set the Active propert y to  True
I get ora-1062: unable to allocate memory for the define buffer. Any
help would be appreciated thanks

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Edson · 2013-11-10 03:12

Hi.

I have experimented some similar. I have made a simple connection,
like you described, and I can run it. But just a simple query of 300
records, make the project use more than 550Mb of RAM.

Probably in your case, it doesn't have too much RAM avalaible.

It seems that the Oracle connection, have a problem in Lazarus (at
least on Windows). I haven't found a solution, until now.

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lawlerp · 2013-11-10 11:51

Quote from: lawlerp on November 09, 2013, 10:54:52 pmHi I was
wondering if somebody could help me with a problem I am having
connecting Lazarus 1.0.12 to an Oracle 11g XE database.

I am using
Lazarus 1.0.12
Oracle XE Version 11.2.0
Windows XP (32 Bit)

I have created a form on which I have dropped the following controls
an OracleConnection a SQLTransaction a SQLQuery a datasource and  a DB
Grid control
OracleConnection properties set as follows
DatabaseName = XE
Hostname=localhost
Username =  ituser
Password = XXXXXX
Once these properties were set I set the Connected property to True

Next I set the SQLTransaction properties as follows
Database=OracleConnection1
Active = True
I noticed afterwards that the OracleConnection.Transaction property
was set to SQLTransaction1

Next I set the SQLQuery1.Transaction property to SQLTransaction1. This
had the effect of setting the SQLQuery1.database property to
OracleConnection1.  When I tried to set the Active propert y to  True
I get ora-1062: unable to allocate memory for the define buffer. Any
help would be appreciated thanks

Replaced the OracleConnection with and ODBC connection. ODBC works
fine. No errors.  I'd like to find a fix the OracleConnection problem
though. I'd prefer use Oracle connection over ODBC - just a personal
preference.

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Edson · 2013-11-10 16:16

I think the Lazarus Oracle client is some abandoned. I had this
problem this since the 1.0.8 (In the 1.2RC1, I can't even  compile a
simple test program).

I've seen some people prefer using Zeos. But I haven't tested.
Probably, it suits to your needs.

IMHO, ODBC is not portable. It depend's on some personal
configurations on the PC.

Personally, I access to Oracle using the sqlplus, like a process, and
controling his inputs/outputs.

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LacaK · 2013-11-10 17:34

It seems that similar problem "unable to allocate memory for the
define buffer" is reported here:
http://bugs.freepascal.org/view.php?id=24723
Can somebody prepare test application which will reproduce this error
with TRUNK (2.7.1) version of FPC? or with 2.6.3 ?

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Edson · 2013-11-15 18:47

I have tested a simple connection in Lazarus 1.2RC1 (FPC 2.6.2):

Code: [Select]procedure TForm1.FormCreate(Sender: TObject);
begin
  SQLquery1.DataBase := OracleConnection1;
  SQLquery1.SQL.Text := 'select table_name from user_tables';
  SQLquery1.Open;
  SQLquery1.Last;
  ShowMessage (intToStr(SQLquery1.RecordCount));
  SQLquery1.First;
  while not SQLquery1.EOF do
  begin
    ShowMessage(SQLquery1.FieldByName('table_name').AsString);
    SQLquery1.Next;
  end;
end;

And it use more than 800Mb of RAM in my PC. My user_tables, just have
350 records.

So I think, the problem persists.