Re: Excel driver for output not working as expected

[Heinrich Schuchardt]

On 12/20/19 4:32 PM, Meketon, Marc via Bug reports for GLPK (GNU Linear
Programming Kit) wrote:
> I am having problems with the Excel driver for writing results.  It is
> not properly clearing out old results.
>
> Since I’m on 64-bit hardware and operating system, I need to use the
> newer versions of Excel (that ones that write to .xlsx files).  I am
> also on Windows 10.
>
> Using the latest GLPK build (4.65), I modified the example
>   sudoku_excel.mod  by these two changes:
>
> In line 50:
>
>    'DRIVER={Microsoft Excel Driver (*.xls, *.xlsx, *.xlsm,
> *.xlsb)};dbq=.\sudoku.xlsx'
>
> And in line:
>
>    'DRIVER={Microsoft Excel Driver (*.xls, *.xlsx, *.xlsm,
> *.xlsb)};READONLY=FALSE;dbq=.\sudoku.xlsx'
>
> Also, I saved the existing  sudoku.xls  into the newer format and called
> it  sudoku.xlsx
>
> When I run the problem **twice** from the  examples\sql  directory,
> using the command line:
>
> ..\..\w64\glpsol.exe --model sudoku_excel.mod
>
> I find that the solution has 81 blank rows, then the solution starts on
> row 83.  So while the ‘UPDATE’ statement clear out the old results, it
> begins to put the new results below.

Hello Marc,

I think this problem is not new. The Excel driver does not support
delete as mentioned in sudoku_excel.mod. For productive use I would
suggest to use a SQL database like MariaDB.

How did you get ODBC finally running with Excel after all the problems
you got into?

Best regards

Heinrich