I am using lazarus 0.9.10 with FBLIB component under win2k,a
lazarus / 16-Databases

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Anonymous · 2006-04-05 09:25

I am using lazarus 0.9.10 with FBLIB component under win2k,and
firebird1.5.3 database server was installed.
Using FBLIB Library,I can create a new firebird database in following
code:
(The corresponing properties such as 'user' and 'password' were set at
design time)
Code: [Select]  TForm1 = class(TForm)
  ...
  FBLDatabase1: TFBLDatabase;
  ...
  procedure TForm1.FormCreate(Sender: TObject);
  var
  DB : string;
  begin
    DB := 'd:\lazarus\dbprojects\test.fdb';
   
FBLDatabase1.CreateDatabase(DB,'sysdba','masterkey',3,4096,'NONE');
  end;

  Now I wonder that if I can do the same thing by using zeos component
set?
  The reason I ask this is because that I would write a DB application
to do things such as creating new database/table,maintaining the
structure of tables,editing records in a dbgrid,etc.But there is no
TTable component in the FBLIB Library.The zeos component set comes
with a TZTable component,but I don't know how to create a new firebird
database by using it.

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matthijs · 2006-04-05 10:28

If you can create a database with ZEOS components I do not know. But
...
You can always use a TQuery component. With TQuery you can do the lot,
display data, edit data, remove records. TTable is a relic left over
from the good old Delphi1 and BDE days.

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Anonymous · 2006-04-07 03:24

I read these files:ZPlainInterbaseDriver.pas,ZPlainFirebird15.pas,
ZPlainloader.pas,and the document Apiguide.pdf
(http://www.ibphoenix.com/downloads/60ApiGuide.zip),
so I made a test application as following:

Code: [Select]unit fbtest;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, LResources, Forms, Controls, Graphics, Dialogs,
  Buttons, Menus, EditBtn, ComCtrls, DBCtrls, DBGrids, DB, sqldb,
  ZDataset, ZConnection, ZSqlProcessor, ZSqlMonitor, ZSequence,
  ZPlainFirebird15, ZPlainInterbaseDriver, windows;

type

  { TForm1 }

  TForm1 = class(TForm)
  ...
  BtnCreateNewDataBase : TButton;
  procedure BtnCreateNewDataBaseClick(Sender: TObject);
  ...

var
  Form1: TForm1;

implementation

...

procedure TForm1.BtnCreateNewDataBaseClick(Sender: TObject);
var
status_vector : PISC_STATUS;
db_handle : TISC_DB_HANDLE;
tran_handle : TISC_TR_HANDLE;
statement : string;
begin
  statement := 'CREATE DATABASE ''C:\mydb\test.fdb'' PAGE_SIZE 4096
USER ''SYSDBA'' PASSWORD ''masterkey'';';
  isc_dsql_execute_immediate := Tisc_dsql_execute_immediate(GetProcAdd
ress(LoadLibrary('C:\FireBird15\bin\fbclient.dll'),'isc_dsql_execute_i
mmediate'));
  db_handle := nil;
  tran_handle := nil;
  isc_dsql_execute_immediate(status_vector,@db_handle,@tran_handle,0,P
Char(statement),3,nil);
end;

The application was compiled and can be run,but when I click on the
BtnCreateNewDataBase,
there is a message 'Access violation.Press OK to ignore,press cancel
to stop the program'.
(I look at the c:\mydb directory,the new database 'test.fdb' was
created and its size is 584kb.)

on page 325 of the document Apiguide.pdf it says:
the 4th parameter of isc_dsql_execute_immediate(Length of the DSQL
statement in bytes) should be set to 0 in C programs to
indicate a null-terminated string.

If I change it to Length(statement),the result is the same as above.

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Marc · 2006-04-07 10:22

first, when loading libs, keep the handle, you need to unload them.

questions:
- does lib := LoadLibrary('C:\FireBird15\bin\fbclient.dll') return a
valid handle ?
- does proc := GetProcAddress(lib,'isc_dsql_execute_immediate' )
return a valid adress ?
- does status_vector need to be initialized ?