Design a database for animals in many lakes

[Björn]

The question about animals vanishing from a lake. As you said there is a problem to make a distinction between no observation and examined but not found. Perhabs I have to make a special table with a Yes/No field and a field with the date when you missed the animal for the first time. Perhabs I could write 0 in a field which means examined but not found and no writing when no examination is done.

 

[David Eagar]

Do you have any actual data to work with?

 

[Björn]

Yes I have lots of data, but I hesitate to make some inputs of that data until I can trust the database. It think it is easier to try and make experiments and see effects in the database if I use a limited amount of data. Just as you did in the database-proposal you presented for me. And I´m not afraid of destroying and loosing the data.

Now I´ve got some problems with one box in a mainform and one in a subform which should read names from a table/query, but they will not.
But I´m still trying to solve it. Of course I have examined your proposal.