Hi Orange! You seem to begin to understand the database. However I need to do some further explanation. The basic of the whole table is that only those companies have bought from our company who are in column 1! Column 2 shows the companies who are related to the company in column 1. Companies in column 3 are related to the company in column 2. So the table might have (and it has) companies which did not by from our company. Those companies who did not buy from our company are present in column 2 or 3.
We update the table 4 times a year, so if there is a change in a company, than we update it as well.


As I told you this file was an excel file, so, so far I imported the whole file to one table. I have only one table (the excel file).

Hansup! I did not manage to try your solution so far as I was very busy! I'll test it tomorrow morning and let you know about it! Thank you.
Have a nice weekend all!