Accessing Clarion Database from Visual Basic 
Author Message
 Accessing Clarion Database from Visual Basic

I have a Clarion app that was written in Clarion for DOS version 2.1 - I
need to access the database from within a Visual Basic application.  Is
there anyway to achieve this (I know very little about Clarion).

Any help / suggestions would be greatly appreciated.

TIA

Eric



Sun, 13 Jan 2002 03:00:00 GMT  
 Accessing Clarion Database from Visual Basic
There are tools (cfile.exe,  I think I've seen that you can get it at the
www.topspeed.com  website)  that you can use to export the data from Clarion
to ASCII or Dbase III or something that you can import into a format Visual
Basic can work with.   You are thus either replacing the existing
application or building a reporting engine that has "historic" data of some
form in it.

Unfortunately for you, there is no ODBC driver for the Clarion format files
and no one has ever brought a driver to the attention of this forum that
would permit you to get into those files natively and interactively with VB.

        Tim

Quote:

> I have a Clarion app that was written in Clarion for DOS version 2.1 - I
> need to access the database from within a Visual Basic application.  Is
> there anyway to achieve this (I know very little about Clarion).

> Any help / suggestions would be greatly appreciated.

> TIA

> Eric


--
Tim Phillips
Vermont Agency of Natural Resources
Department of Environmental Conservation


Sun, 13 Jan 2002 03:00:00 GMT  
 Accessing Clarion Database from Visual Basic

Quote:

> Unfortunately for you, there is no ODBC driver for the Clarion format files
> and no one has ever brought a driver to the attention of this forum that
> would permit you to get into those files natively and interactively with VB.

If you have $ to burn(750 or more), you can buy DJengine from DataJunction and
call it from VB. I dont know if they allow record level access or not.

---
Mark Riffey
Granite Bear Development
http://www.granitebear.com

Software for professional photography studios
and non-profit organizations



Sun, 13 Jan 2002 03:00:00 GMT  
 Accessing Clarion Database from Visual Basic
Quote:

> Unfortunately for you, there is no ODBC driver for the Clarion format files
> and no one has ever brought a driver to the attention of this forum that
> would permit you to get into those files natively and interactively with VB.

The file format for Cla (clarion) files is public domain so if you want to
access the data you could. Would be a bit of work but not hopeless.  
---------
Jim Kane  - TeamTopSpeed
Productive Software Solutions
Can't Find that Message?
Get Organized, Get ForKeeps!
www.fkeeps.com


Sun, 13 Jan 2002 03:00:00 GMT  
 Accessing Clarion Database from Visual Basic

Quote:


>> Unfortunately for you, there is no ODBC driver for the Clarion format
files
>> and no one has ever brought a driver to the attention of this forum that
>> would permit you to get into those files natively and interactively with
VB.

>The file format for Cla (clarion) files is public domain so if you want to
>access the data you could. Would be a bit of work but not hopeless.

These files, on my system, have a .dat extension - are they not clarion
files?  If they are clarion files do you know where I could find any public
domain literature on the file layouts?  The clarion app is a mission
critical app that I do not want to replace, however, I do need to add
reporting capabilities from the app into our existing VB based EIS system

Thanks,

Eric Scantlebury



Sun, 13 Jan 2002 03:00:00 GMT  
 Accessing Clarion Database from Visual Basic

Quote:


>> Unfortunately for you, there is no ODBC driver for the Clarion format
files
>> and no one has ever brought a driver to the attention of this forum that
>> would permit you to get into those files natively and interactively with
VB.

>If you have $ to burn(750 or more), you can buy DJengine from DataJunction
and
>call it from VB. I dont know if they allow record level access or not.

If they can do what their web site says then I may loose the money very
quickly.  I need access to these files - thanks for the help.

Eric Scantlebury



Sun, 13 Jan 2002 03:00:00 GMT  
 Accessing Clarion Database from Visual Basic


Quote:
> These files, on my system, have a .dat extension - are they not clarion
> files?  If they are clarion files do you know where I could find any public
> domain literature on the file layouts?  The clarion app is a mission
> critical app that I do not want to replace, however, I do need to add
> reporting capabilities from the app into our existing VB based EIS system

yes .dat is correct. I dont know what I was thinking. I got the formats from
Topspeeds web site a long time ago.  I found the file.
_______
Jim Kane  - TeamTopSpeed
Productive Software Solutions
Can't Find that Message?
Get Organized, Get ForKeeps!
www.fkeeps.com


Sun, 13 Jan 2002 03:00:00 GMT  
 Accessing Clarion Database from Visual Basic
Hi Eric:

You will need to create "wrapper" functions, using the Pascal calling
convention, for any Clarion file handling funtions that you wish to call
from VB. You will also need to create "memory copy" functions that will
copy data to and from the Clarion Record structure and an identical data
structure within your VB program. Here is a quote from my book titled
The Clarion Companion, Chapter 18 - Building reusable components.

<begin quote>
There are a variety of things you must do in order to make a Clarion DLL
that will be (might be?) compatible when called from a non-Clarion
language.  The following list of seven considerations is a good start
but it still may not produce acceptable results due to Clarion's
proprietary compiler technology.  The considerations include:

1. Calling Convention
Use the PASCAL attribute on all of your exported procedures and
functions.  This suppresses the JPI register-based calling convention
and makes sure that parameters are placed on the stack in an order that
the caller can access.  You can even build "wrappers" around Clarion
functions so that the external calling convention is PASCAL.  For
example, suppose you want to access the Clarion ERRORCODE() function
from a DLL using a foreign language.  Then the prototype would be:

  WRAP_ErrorCode(),LONG,PASCAL,NAME('WRAP_ERRORCODE')

And the function code would be:

WRAP_ErrorCode     FUNCTION
  CODE
  RETURN(ERRORCODE())

The above prototype and code will create a wrap function called
WRAP_ErrorCode() that does nothing more than call ERRORCODE() and return
its value on the stack according to the PASCAL calling convention.

<end quote>

Quote:

> I have a Clarion app that was written in Clarion for DOS version 2.1 - I
> need to access the database from within a Visual Basic application.  Is
> there anyway to achieve this (I know very little about Clarion).

> Any help / suggestions would be greatly appreciated.

> TIA

> Eric


--
 Randy Goodhew
 =[oooooooooo]=


Mon, 14 Jan 2002 03:00:00 GMT  
 
 [ 8 post ] 

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