How do I change the path of my database when running the program?

Question

How do I change the path of my database when running the program?

I'm starting to program with Delphi XE8and using Firebird 2.5.

I managed to implement my database and it is working all right.

The problem I'm facing now is that as I switch from computers to programming (home, college, etc), I have to change the path where my database file is located, compile and only then can I run the program.

I want to change the configuration of my TSQL Connection at runtime and not having to compile the program every time I switch computer.

In this case, create a form with the program settings or, before the program initializes, request the database path.

In the image is highlighted the property I want to modify.

I tried with this code:

   procedure TDMDados.ConexaoBeforeConnect(Sender: TObject);
   begin
       Conexao.Params:= 'Caminho do arquivo';
   end;

The problem is that, as I have already configured this connection, this parameter is already set.

Some connection parameters:

   DriverName=Firebird
   DriverUnit=Data.DBXFirebird
   DriverPackageLoader=TDBXDynalinkDriverLoader,DbxCommonDriver220.bpl
   DriverAssemblyLoader=Borland.Data.TDBXDynalinkDriverLoader,Borland.Data.DbxCommonDriver,Version=22.0.0.0,Culture=neutral,PublicKeyToken=91d62ebb5b0d1b1b
   MetaDataPackageLoader=TDBXFirebirdMetaDataCommandFactory,DbxFirebirdDriver220.bpl
   MetaDataAssemblyLoader=Borland.Data.TDBXFirebirdMetaDataCommandFactory,Borland.Data.DbxFirebirdDriver,Version=22.0.0.0,Culture=neutral,PublicKeyToken=91d62ebb5b0d1b1b
   LibraryName=dbxfb.dll
   LibraryNameOsx=libsqlfb.dylib
   VendorLib=fbclient.dll
   VendorLibWin64=fbclient.dll
   VendorLibOsx=/Library/Frameworks/Firebird.framework/Firebird
   Database=C:\Users\Johnny\Dropbox\1.MESTRADO\10.DISSERTAÇÃO\PROGRAMA DELPHI\Banco de dados\bd.fdb
   User_Name=sysdba
   Password=masterkey
   Role=RoleName
   [...]

My intention is to change this parameter of the connection at runtime:

Database=C:\Users\Johnny\Dropbox\1.MESTRADO\10.DISSERTAÇÃO\PROGRAMA DELPHI\Banco de dados\bd.fdb

"- I still haven't been able to try to do this because I don't know how to start. I know how to change the parameters of the connection before compiling ".

2

delphi firebird delphi-xe8 object-pascal

Author: LGregianin, 2019-01-20

Source

1 answers

score 1 · Answer 1

After getting a lot here is the solution I got, it met my need satisfactorily.

Before the program creates the form1 the user is asked to select the file from the database, then the program manages to get the file path. I created a function (SelectBDpath) to get the file path and sequentially called the function and applied it to a variable which will be used in my DataModule.

function SelectBDpath() : string ;
var
    selectedFile: string;
    dlg: TOpenDialog;
begin
    selectedFile := '';
    dlg := TOpenDialog.Create(nil);
    try
        dlg.InitialDir := GetCurrentDir;
        dlg.Filter :=   'Firebird DB Files|*.FDB';
        if dlg.Execute
            then
                SelectBDpath := dlg.FileName;
    finally
        dlg.Free;
   end;
end;
//Evento *OnCreate*
procedure TForm1.FormCreate(Sender: TObject);
    begin
        BDpath:=SelectBDpath();
        DMDados.Conexao.Open;
end;

In sequence my DataModule , before the connection occurs, "pulls" the file path (bdpath) of Form1 (for this it is necessary to put Unit corresponding in uses of DataModule ) and applies in the parameters of the connection of my database, as code below:

procedure TDMDados.ConexaoBeforeConnect(Sender: TObject);
    begin
        Conexao.Params.Values['Database']:= BDpath;
    end;

This way every time I run the program it will ask to select the file from my database and apply on the parameters of the connection.