Dear Tim,

we haven't heard us lately. I am a satisfied DBISAM user (registered
for TechnoLab GmbH and 4-Text). Maybe you remember. Last time we
talked about big blob fileds... Anyway...

I have a problem. But let me explain you first something:

We have a local database with a table that contains the relative path
in a string field to a file, e.g. "files\mypic.jpg". This is in
SessionType relatively easy to access, e.g. via ShellExecute.

Now we convert the database to Client/Server mode. How can I open for
example this file in a clinet server mode. We use the dbsvr.exe and
the admin tool. Can I use any event of the dbsrvr.exe-tool to open the
file with a relative path of the desired database (running in/at
dbsvr.exe)? If yes, could you please give me an example how this would
work in Client/Server mode. the files are in a relative directory in
the database direrectory, for example "\data\files". The database is
in "data" and the files to open in "data\files" (any format). How can
I do that?

I really appreciate your help.

Thanks in advance.

Ralph

Ralph

There are examples in the help file that do this (almost). The main
example sends back a text file assuming a fully qualified path name.
Since you have a relative path you probably need a snippet from another
example (the scheduled backup) as well. Untested (I'm just editing the
help example on the fly):


procedure TMyForm.ServerProcedure(Sender: TObject;
  ServerSession: TDBISAMSession; const ProcedureName: String);
var
   TempFileName, TempPath, TempDesc: string;
begin
   if (AnsiCompareText(ProcedureName,'JPGFile')=0) then
      begin
      with ServerSession do
         begin
         ServerEngine.GetServerDatabase(
                      RemoteParams.ParamByName('DatabaseName').AsString,
                      TempDesc,
                      TempPath);
         TempFileName:= IncludeTrailingBackslash(TempPath)+
                        RemoteParams.ParamByName('FileName').AsString;
         { Now clear the parameters for use in populating
           the result parameters }
         RemoteParams.Clear;
         if FileExists(TempFileName) then
            begin
            { If the file exists, use the TDBISAMParam
              LoadFromFile method to load the file
              data into the parameter }
            with RemoteParams.CreateParam(ftBlob,'FileContents') do
               LoadFromFile(TempFileName,ftBlob);
            end
         else
            { If the file doesn't exist, just create a NULL
              parameter with the correct result name }
            RemoteParams.CreateParam(ftBlob,'FileContents');
         end;
      end;
end;

Hi thanks for your quick reply,

do I need to do this in the srvr.exe or in my seperate application...?

Thank you again.

Ralph

Eryk Bottomley <no@way.com> wrote:

Ralph

There are examples in the help file that do this (almost). The main
example sends back a text file assuming a fully qualified path name.
Since you have a relative path you probably need a snippet from another
example (the scheduled backup) as well. Untested (I'm just editing the
help example on the fly):


procedure TMyForm.ServerProcedure(Sender: TObject;
  ServerSession: TDBISAMSession; const ProcedureName: String);
var
   TempFileName, TempPath, TempDesc: string;
begin
   if (AnsiCompareText(ProcedureName,'JPGFile')=0) then
      begin
      with ServerSession do
         begin
         ServerEngine.GetServerDatabase(
                      RemoteParams.ParamByName('DatabaseName').AsString,
                      TempDesc,
                      TempPath);
         TempFileName:= IncludeTrailingBackslash(TempPath)+
                        RemoteParams.ParamByName('FileName').AsString;
         { Now clear the parameters for use in populating
           the result parameters }
         RemoteParams.Clear;
         if FileExists(TempFileName) then
            begin
            { If the file exists, use the TDBISAMParam
              LoadFromFile method to load the file
              data into the parameter }
            with RemoteParams.CreateParam(ftBlob,'FileContents') do
               LoadFromFile(TempFileName,ftBlob);
            end
         else
            { If the file doesn't exist, just create a NULL
              parameter with the correct result name }
            RemoteParams.CreateParam(ftBlob,'FileContents');
         end;
      end;
end;

Ralph,

> do I need to do this in the srvr.exe or in my seperate application...?

You have to add code like that to the DBISAM server and re-compile it.
You then use SrvAdmin to 'register' the stored procedure and grant
execute rights to the appropriate user accounts and finally use
Session.CallRemoteProcedure from your client application to use the new
functionality.

Eryk

Ralph,

Eryk nailed the answer again on this one - what you want is a server-side
procedure.

--
Tim Young
Elevate Software
www.elevatesoft.com

Hi thanks again,

maybe i am a bit silly or sth. So please step by step again. Thank you really in advance.

1. I write this code (above) in the event: "onServerProcedure" in the dbsrvr.dpr-project.

2. I re-compiled it to a new dbsrvr.exe

3. Registering the procedure? But How? Do I need to use the tabsheet "procedures"? or
"procedure users" What do I need to type there exactly in? "onServerProcedure"?

4. Which rights are necessary to ececute this procedure? and where can I adjust it?

5. Do I call from my normal application "Session.CallRemoteProcedure" (and nothing more? I
mean without parameters or somtething...?!) to execute this procedure?

To Tim: Yeah, The server needs to execute (e.g. open a file on a client's demand.)... Any
code examples?

I really thank you all so much.

Thank you.

Ralph

Eryk Bottomley <no@way.com> wrote:

Ralph,

> do I need to do this in the srvr.exe or in my seperate application...?

You have to add code like that to the DBISAM server and re-compile it.
You then use SrvAdmin to 'register' the stored procedure and grant
execute rights to the appropriate user accounts and finally use
Session.CallRemoteProcedure from your client application to use the new
functionality.

Eryk

Hello Tim,

how does it work with a server side procedure. <please please could you give me a useful
example? For the client side and the server side that needs to open any file e.g. via
shelexecute and all the adjustments in the admin-tool.

Sorry for annoying.

Thanks so much.

Ralph

I've just read in the help files about server procedures.... is this procedure always
relevant for the selected record in the table?

Thanks,

Ralph




Ralph <ralphdietrich@gmail.com> wrote:

Hello Tim,

how does it work with a server side procedure. <please please could you give me a useful
example? For the client side and the server side that needs to open any file e.g. via
shelexecute and all the adjustments in the admin-tool.

Sorry for annoying.

Thanks so much.

Ralph

Ralph,

> 1. I write this code (above) in the event: "onServerProcedure" in the dbsrvr.dpr-project.
>
> 2. I re-compiled it to a new dbsrvr.exe

Yes.

> 3. Registering the procedure? But How? Do I need to use the tabsheet "procedures"? or
> "procedure users" What do I need to type there exactly in? "onServerProcedure"?

I always do it in code so I don't remember the UI too well for this. The
procedure name in the example I posted is 'JPGFile' and you add that to
the appropriate database using the 'Procedures' tab. The 'Procedure
Users' tab then specifies whether specific users can execute the
procedure or not (Admin user can always access procedures by default).

> 4. Which rights are necessary to ececute this procedure? and where can I adjust it?

'Execute' ...and that is the only right appropriate to a stored procedure.

> 5. Do I call from my normal application "Session.CallRemoteProcedure" (and nothing more? I
> mean without parameters or somtething...?!) to execute this procedure?

No, you call it along the following lines (adapting a help file example
again):

begin
   with MyRemoteSession do
      begin
        RemoteParams.CreateParam(ftString,'DatabaseName').AsString:='Main';
RemoteParams.CreateParam(ftString,'FileName').AsString :=
    MyTable.FieldByName('FileName').AsString;
      try
         { Now call the procedure }
         CallRemoteProcedure('JPGFile');
         if not ParamByName('FileContents').IsNull then begin
           ParamByName('FileContents').SaveToFile(
               MyTable.FieldByName('FileName').AsString);
           MyShellExecute(MyTable.FieldByName('FileName').AsString);
         end;
      except
         ShowMessage('There was an error calling the '+
                     'server-side procedure');
      end;
      end;
end;

....there is a silly assumption there since I saved the JPG file to the
client hard disk using the relative path and name from the database
without checking if it is valid or if the file already exists etc.
Typically you would get a temporary file name from the OS and create the
local copy in the user's temporary files directory (and also erase it
when finished). 'MyShellExecute' is just an imaginary wrapper for
ShellExecute since I can't be bothered looking up what parameters it
takes

Eryk

Ralph,

<< I've just read in the help files about server procedures.... is this
procedure always relevant for the selected record in the table? >>

Server-side procedures have no relation whatsoever to a table.

--
Tim Young
Elevate Software
www.elevatesoft.com