Question

I have a MySQL table named “relations”, as follows:

from to count
-------------
A    B  456
A    C  233
A    D  463
B    A  766
B    C  215
B    D  142

(In reality, “from” and “to” contain names of people and the table contains 150 rows). I now need to export this table to an excel file (not CSV) in (150×150) matrix form, like this:

  |  A    B    C   D
--+------------------
A |  0   456  233 463
B | 766   0   215 142

I need to do this from within PHP, but don’t know how to go about this. Do I first create an empty Excel file, naming all the rows and columns? (so like this:)

  |  A    B    C   D
--+------------------
A |
B |

If I do this, then how can I connect to the right cell to insert the correct counts? Or do I write the Excel file from within PHP alltogether?

Also, in reality the table is not structured, so it looks something like:

from to
-------
A    C
F    K
F    L
B    Z
M    P
P    A

So I don’t think I’m able to write cell-by-cell, row-for-row. Or I should first query the database to sort by column “from” and then by column “to”, probably.

Any help to get me started would be greatly appreciated.